PSY280 Final Exam

M ganglion cells

"Large cells." Connect to the magnocellular pathway: involved in motion processing. Excellent temporal resolution, but poor spatial resolution

Oliver Selfridge's computational model of letter recognition

"Perception by committee" "Demons" loosely represent neurons; each level represents a different brain area

P ganglion cells

"Small cells." Connect to the parvocellular pathway; involved in fine visual acuity, color, and shape processing. They have poor temporal resolution but good spatial resolution

Presbyopia

"old sight" inability to accomodate nearby objects

Vagus nerve

(Cranial nerve X) - for the fixed part of the tongue furthest in the back of the mouth cavity

Fundamental frequency

(first harmonic): lowest frequency component of the sound Perception of timbre depends on context in which sound is heard

Anatomy of a neuron

- Dendrites : fibers that receive messages from other neurons - Cell body (with nucleus) integrates incoming signals from dendrites - Axons : fibers that carry outgoing signals to other neurons or organs. There are gaps between - Synapse: region where the neuron meets other neuron or target cell - Signals are sent via Neurotransmitters

Receptive field properties of IT neurons

- Very large—some cover half the visual field - Don't respond well to spots or lines - Do respond well to stimuli such as hands, faces, or objects, animals, and vehicles

OFF-center ganglion cell responds when

-offset of small bright light in center of receptive field -onset of annulus of light in surround of receptive field

ON-center ganglion cell responds when

-onset of small bright light in center of receptive field -offset of annulus of light in surround of receptive field

Where is the ILD nonexistent

0 degrees and 180 degrees

Cortical magnification

1 degree of visual angle at fovea is processed by at 15 times more neurons than 1 degree of visual angle just 10 degrees away from fovea

Absolute threshold for taste

1 teaspoon of sugar in 2 gallons of water

Viewpoint Invariance

1. A property of an object that does not change when observer viewpoint changes. 2. A class of theories of object recognition that proposes representations of objects that do not change when viewpoint changes.

summary of midlevel vision

1. Bring together what should be brought together. - GROUPING MECHANISMS 2. Split asunder what should be split asunder. - FIGURE GROUND SEGMENTATION 3. Use what you know. - Use heuristics for findings corners, etc... and divide objects into parts. 4. Avoid accidents. - Do not consider as likely accidental view point representations 5. Seek consensus and avoid ambiguity.

Three steps to color perception

1. Detection 2. Discrimination 3. Appearance

Four tactile receptors

1. Meissner corpuscles 2. Merkel cell neutrite complexes 3. Pacinian corpuscles 4. Ruffini endings

Vertical Pathway

1. Photoreceptor 2. Bipolar Cell 3. Ganglion

What are the steps to face perception

1. Recognition of face parts 2. Recognition of the spatial configuration of these parts

Three ways responses of a cell could be changed by attention

1. Response enhancement 2. Sharper tuning 3. Altered tuning

What are the stages of stereopsis

1. Selection of a depth plane (horopter) using vengeance eye movements and accommodation 2. Computation of binocular disparity, which provides depth information relative to the horopter

How do you build a motion detector

1. Start with two adjacent receptors 2. register change in position 3. Incorporate a delay to account for change in time

what are the four steps for subtractive color mixture?

1. Take white light that contains a broad mixture of wavelengths 2. Pass it through a filter that absorbs shorter wavelengths. The result will look yellowish 3. Pass that through a blush filter that absorbs all but a middle range of wavelengths 4. The wavelengths that make it through the filters will be a mix that looks greenish

Neural transduction of sound energy at the stereocilia

1. Tip link mechanically opens potassium channels 2. Potassium enters cell, leading to depolarization of the cell membrane 3. Depolarization opens calcium channels, causing vesicles to fuse with cell membrane and release neurotransmitters into the synaptic cleft 4. Postsynaptic button of the afferent auditory nerve gets activated by the neurotransmitter 5. Firing of auditory nerve fibers into patterns of neural activity finally completes process of translating sound waves into patterns of neural activity (sensation)

Two important features of the striate cortex

1. Topographical Mapping 2. Dramatic scaling of information from different parts of the visual field

What is the path of image processing from the eyeball to the brain?

1. eye (vertical path) photoreceptors bipolar cells retinal ganglion cells 2. lateral geniculate nucleus 3. striate cortex

Biochemical cascade caused by light

1. light hits rhodopsin in retina 2. causes the attached retinal to change form from cis to trans 3. G-protein activated (transducin) 4. transducin activates phosphdiesterase enzyme 5. The enzyme changes cGMP to GMP (cGMP is what binds/opens sodium channels to depolarize cells in the dark) 6. with less cGMP, less sodium channels open, cells becomes more negative, hyperpolarizes (potassiums equ. potential) (potassium channels always open)

Three mechanisms for cognitive habituation

1. olfactory receptors internalized into cell bodies during odor adaptation may be hindered after continuous exposure, take longer to recycle 2. Odorant molecules may be absorbed into bloodstream, causing adaptation to continue 3. Cognitive-emotional factors (healthful vs. harmful odor experiment)

Three attributes of touch receptors

1. type of stimulation the receptor responds to (pressure, temperature, pain) 2) size of the receptive field (portion of skin the receptor responds to) 3) rate of adaptation (how fast it will fatigue

Contrast Sensitivity Function peaks when?

2-4 Cycles/degree for photopic (daylight) vision, reduced for mesopic (twiglight) and scotopic (nighttime) vision

Human hearing uses a limited range of sound energy

20 to 20,000 Hz

What sound range can college aged people hear?

20-15,000Hz

What sound range can young people hear?

20-20,000Hz

What is the critical period for human vision?

3-8 years

Hypercolumn

A 1x1-mm block of striate cortex containing "all the machinery necessary to look after everything the striate cortex is responsible for, in a certain small part of the visual world" Many columns with preference for range of orientations Left and right eye Even color

Cribriform plate

A bony structure riddled with tiny holes, at the level of the eyebrows, that separates the nose from the brain Axons from OSNs pass through the tiny holes to enter the brain

Edge detector

A cell in the visual cortex that responds most to edges in the visual field.

cone-opponent cell

A cell type—found in the retina, lateral geniculate nucleus, and visual cortex—that, in effect, subtracts one type of cone input from another.

Vomeronasal organ

A chemical sensing organ at the base of the nasal cavity of many animals with a curved tubular shape evolved to detect chemicals that cannot be processed by the olfactory epithelium, such as large and/or aqueous molecules - the types of molecules that constitute pheromones

Neurotransmitter

A chemical substance used in neuronal communication at synapses

Color contrast

A color perception effect in which the color of one region induces the opponent color in a neighboring region

Color assimilation

A color perception effect in which two colors bleed into each other, each taking on some of the chromatic quality of the other

Relative size

A comparison of size between items without knowing the absolute size of either one

Illusory contour

A contour that is perceived even though nothing changes from one side of the contour to the other in the image

Object recognition should be seen as what?

A conversation among many parts of the brain rather than as a one way progression

Occlusion

A cue to relative depth order when , for example, one object obstructs the view of part of another object

Two groups of nociceptors

A delta fibers C fibers

Texture Gradient

A depth cue based on the geometric fact that items of the same size form smaller images when they are farther away Two items that are same size, the one farther away from you is perceived as smaller

Aerial Perspective

A depth cue based on the implicit understanding that light is scattered by the atmosphere more light is scattered when we look through more atmosphere more distant objects appear fainter, bluer, and less distinct

Relative metrical depth cue

A depth cue that could specify, for example, that object A is twice as far away as object B without providing information about the absolute distance to either A or B

Monocular depth cue

A depth cue that is available even when the world is viewed with one eye alone

Absolute metrical depth cue

A depth cue that provides quantifiable information about distance in the third dimension

Binocular depth cue

A depth cue that relies on information from both eyes

structural description

A description of an object in terms of the nature of its constituent parts and the relationships between those parts

Amblyopia

A developmental disorder characterized by reduced spatial vision in an otherwise healthy eye, even with proper correction for refractive error

Stereoscope

A device for presenting one image to one eye and another image to the other eye, creating a single, three-dimensional design

Absolute disparity

A difference in the actual retinal coordinates in the left and right eyes of the image of a feature in the visual scene (used for control of convergence)

Ames room

A distorted room to generate optical distance and size illusions

wave

A disturbance that transfers energy from place to place

retinitis pigmentosa

A family of hereditary diseases that involve the progressive death of photoreceptors and degeneration of the pigment epithelium

Uniqueness Constraint

A feature in the world will be represented exactly once in each retinal image

Dithering

A form of color quantization, resulting in a reduction of the number of colors needed

Efferent Copy

A form of sensory input from muscles

cupula

A gelatin-like structure containing a tuft of hairlike sensory receptor cells in the semicircular canals.

equal loudness curve

A graph plotting sound pressure level (dB SPL) against the frequency for which a listener perceives constant loudness.

Middle vision

A loosely-defined stage of visual processing that comes after basic features have been extracted from the image and before object recognition and scene understanding Involves the perception of edges and surfaces Determines which regions of an image should be grouped together into objects

Audibility threshold

A map of just barely audible tones of varying frequencies

Stereoacuity

A measure of the smallest binocular disparity that can generate a sensation of depth

Reaction time

A measure of the time from the onset of a stimulus to a response

Habituation procedure

A method for studying infant perception. After some exposure to a stimulus, an infant becomes habituated and stops paying attention to it. If the infant shows renewed interest when a new stimulus is presented, this reveals that the infant regards the new stimulus as different from the old one.

Inferior Colliculus

A midbrain nucleus in the auditory pathway

Strabismus

A misalignment of the two eyes such that a single object in space is imaged on the fovea of one eye, and on the nonfoveal area of the other (turned) eye

koniocellular cell

A neuron located between the Magnocellular and parvocellular layers of the lateral geniculate nucleus

Cone-opponent cell (or color-opponent cell)

A neuron whose output is based on a difference between sets of cones

Bandpass noise

A noise signal that contains a limited range of sound frequencies

Entorhinal cortex

A phylogenetically old cortical region that provides major sensory association input to the hippocampus. Also receives direct projections from olfactory regions

Visual field defect

A portion of the visual field with no vision or with abnormal vision, typically resulting from damage to the visual nervous system

Color-matching experiment

A procedure in which observers are asked to match the color in one field by mixing two or more lights in another field.

Belt Area

A region of cortex, directly adjacent to A1, with inputs from A1, where neurons respond to more complex characteristics of sounds

Parabelt Area

A region of cortex, lateral and adjacent to the belt area, where neurons respond to more complex characteristics of sounds, as well as to input from other senses

Lesion

A region of damaged brain To destroy a section of the brain

medial superior olive (MSO)

A relay station in the brain stem where inputs from both ears contribute to detection of the interaural time difference.

on center ganglion cell

A retinal ganglion cell that is activated when light is presented to the center, rather than the periphery, of the cell's receptive field. increases firing in response to an increase in light intensity in its receptive field center

Vertigo

A sensation of rotation or spinning

The Reichardt Motion Detector

A simple motion detection circuit proposed by Werner Reichardt Based on delay and compare fires only if signals from both detectors arrive at the comparator at the same time

Illusory conjunctions

A situation, demonstrated in experiments by Anne Treisman, in which features from different objects are inappropriately combined.

prism

A solid figure that has two congruent, parallel polygons as its bases. Its sides are parallelograms

Bayesian Approach

A statistical model based on Reverend Thomas Bayes' insight that prior knowledge could influence your estimates of the probability of a current event

random dot stereogram

A stereogram made of a large number of randomly placed dots RDSs contain no monocular cues to depth Stimuli visible stereoscopically in RDSs are cyclopean stimuli

Cue

A stimulus that might indicate where (or what) a subsequent stimulus will be: valid vs. invalid vs. neutral

Organ of Corti

A structure on the basilar membrane of the cochlea composed of hair cells and dendrites of auditory nerve fibers Movements of the cochlear partition translated into neural signals by structures in organ of corti

What advantage do sensory systems provide?

A survival advantage

Ideal observer

A theoretical observer with complete access to the best available information and the ability to combine different sources of information in the optimal manner it can be useful to compare human performance to that of an ideal observer

Absolute threshold vestibular

A tilt of less than half a minute on a clock face

Hertz

A unit of measure for frequency One hz equals one cycle per second

Decibel

A unit of measure for the physical intensity of sound Named after inventor of the telephone: Alexander Graham Bell Difference between two sounds as the ratio between two sound pressures p0 is typically based on faintest sound pressure we can hear Each 10:1 sound pressure ratio equals 20 dB, and a 100:1 ratio equals 40 dB Doubling in sound pressure corresponds to 6 dB Ratio between faintest and loudest sounds is more than 1:1,000,000

Column

A vertical arrangement of neurons. Neurons within a single column tend to have similar receptive fields and similar orientation preferences.

Afterimage

A visual image seen after the stimulus has been removed

Vestibulo-spinal responses

A whole family of reflexes that work together to keep us from falling over Without vestibulo-spinal responses, we would be unable to stand up in the dark Patients with vestibular loss actually over-compensate for body sway

Convergence

Ability of the two eyes to turn inward; reduces the disparity of the feature to zero, or near zero two eyes turning inward

Divergence

Ability of the two eyes to turn outward; reduces the disparity of the feature to zero, or near zero Two eyes turning outward

When is the fovea fully developed?

About four years old

Accidental viewpoints

Accidental co-terminations can lead to illusory depth perception due to erroneous assumptions of contiguity

otoacoustic emissions

Active amplification of sounds by the outer hair cells leads to production of sound by the ear

When do cones and rods develop and organize?

After Birth

How do you locate a sound?

All auditory signals get summed in the ear canal (Owl example) Similar dilemma to determining how far an object is two ears: critical for determining auditory locations

Striate Cortex

Also known as the primary visual cortex or V1, major transformation of visual information takes place here Consists of about 200 million cells

Binocular summation

An advantage in detecting a stimulus that is afforded by having two eyes rather than just one Two retinal images of a 3D world are not the same

Negative after image

An afterimage whose polarity is the opposite of the original stimulus light stimulus produce dark negative afterimages

parahippocampal place area (PPA)

An area in the temporal lobe that contains neurons that are selectively activated by pictures of indoor and outdoor scenes. Prefers scenes over faces or objects

Tonotopic Organization

An arrangement in which neurons that respond to different frequencies are organized anatomically in order of frequency Maintained in primary auditory cortex Neurons from A1 project to belt area, then to parabelt area

Superior Olive

An early brain stem region in the auditory pathway where inputs from both ears converge

Boundary extension

An error of committing a scene to memory in which people confidently remember seeing a surrounding region of a scene that was not visible in the studied view

rapid serial visual presentation (RSVP)

An experimental procedure in which stimuli appear in a stream at one location (typically the point of fixation) at a rapid rate (typically about eight per second).

Ponzo illusion

An illusion of size in which two objects of equal size that are positioned between two converging lines appear to be different in size. Also called the railroad track illusion.

Horopter

An imaginary surface that passes through the point of fixation. Images caused by a visual stimulus on this surface fall on corresponding points on the two retinas. The empirical location of objects whose images lie on the corresponding points The surface of zero disparity - surface in 3d space Based on actual tests of disparity (i.e., theory doesn't match reality)

Achromatopsia

An inability to perceive colors that is due to damage to the central nervous system

Problem of univariance

An infinite set of different wavelength intensity combinations can elicit exactly the same response from a single type of photoreceptor this means color discriminations cannot be based on only one type of photoreceptor

Criterion

An internal threshold set by the observer. If the internal response is above ______, the observer gives one response (e.g., "yes, I hear that"). Below ______, the observer gives another response (e.g., "no, I hear nothing")

Microsaccade

An involuntary, small, jerk-like eye movement

Texture defined object

An object that is defined by changes in contrast or texture, but not by luminance apart of second order motion

How doe we process the components in an odor mixture?

Analyses Synthesis

Feature integration Theory

Anne Treisman's theory of visual attention, which holds that a limited set of basic features can be processed in parallel preattentively, but that other properties, including the correct binding of features to objects, require attention.

parvocellular layer

Any of the top four neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically smaller than those in the bottom two layers Contains the midget system and is adapted for details in static objects

Frontal Eye Field (FEF)

Area in frontal cortex that represents targets of eye movements in retinotopic coordinates

Coding of direction in the otolith organs

Arises in part from the anatomical orientation of the organ s Utricular macula: horizontal plane Saccular macula: vertical plane

Rotation perception

At first, constant rotation (in the dark) is perceived accurately Soon, however, subjects feel as if they are slowing down After 30 seconds, they no longer feel as if they are rotating time course of habituation for perceived velocity slower than time course of habituation for velocity neurons "velocity storage" when rotation stops, subjects feel as if they are rotating in the opposite direction

Identification

Attaching a verbal label to a smell is not always easy Tip-of-the-nose phenomenon

Conjunction search

Attend to multiple feature dimension Steep search slope, serial search, non-efficient search: takes twice as long to decide target absence

Internal

Attending to one line of thought over another or selecting one response over another shows up in memory retrieval

External

Attending to stimuli in the world

Covert

Attending without giving an outward sign you are doing so

Spotlight model

Attention moves from one point to the next

What are canal afferent neurons sensitive to

Back and forth rotations of the head as well greatest sensitivity to rotations at 1 Hz or less Faster rotations than 1 Hz would be dangerous Firing rate goes up and down as the head rotates back and forth the overall normalized amplitude of the canal neuron response scales with head rotation frequency

Motion parallax

Based on head movement; geometric information obtained from two eyes in different positions in the head at the same time

Bottom-up attention

Based on low-level image properties Determined by salience Automatic Fast deployment

Why are young children not very sensitive to high spatial frequencies?

Because their visual system is still developing

Where is a large proportion of processing done in the auditory system?

Before A1

What we smell can affect what we see (Zhou et al., 2010)

Binocular rivalry stimulus of markers in one eye and rose in the other Subjects switch back and forth between seeing one or the other stimulus When the smell of markers or roses was presented to their nostrils, subjects saw the corresponding stimulus more often

olfactory bulb

Blueberry-sized extension of the brain just above the nose, where olfactory information is processed There are two olfactory bulbs, one in each brain hemisphere, corresponding to the left and right nostrils. Connections are ipsilateral (Same side of the body) Unlike vision, hearing or touch, which are contralateral

Genetic basis of olfactory receptors

Buck and Axel (1991): Genome contains about 1000 different olfactory receeptor genes; each codes for a single type of OR All mammals have pretty much the same set of 1000 genes. However, some genes are non-functional pseudogenes Dogs and mice: About 20% are pseudogenes Humans: Between 60-70% are pseudogenes Each person has a different number of pseudogenes, resulting in individual differences in sensitivity to smells There may be an evolutionary trade-off between vision and olfaction

How is strabismus treated?

By patching the dominant eye

How is attention deployed?

By things you know (your own decisions, biases, knowledge, etc) Things you see (which items are most salient, unique,e tc.

How does Escher fool us with his drawings?

Cannot sort out the perception of space in his drawings

texture segmentation

Carving an image into regions of common texture properties

simple cells

Cells in V1 that respond to line, or gradient, oriented in particular direction Phase sensitive

Complex Cells

Cells in V2 that give best response to moving lines of particular orientation Do not have clearly defined excitatory and inhibitory regions Phase insensitive Respond to bar, regardless of exact positioning within receptive field

Photoreceptors

Cells in the retina that initially transduce light energy into neural energy (100 million in each eye)

frequency selectivity

Clearest with very faint sounds

Sour

Comes from acidic substances At high concentrations, acids will damage both external and internal body tissues Hydrogen ions inside the receptor cell trigger sour perception many people like sour in low concentrations

Do we use optic flow information?

Computer-generated displays of moving dots and lines to stimulate optic flow information Humans can detect differences in heading of 1 degree of visual angle only with optic flow

How are the circular receptive fields in the LGN transformed into the elongated receptive fields in striate cortex?

Concentric LGN cells that feed into a cortical cell are all in a row

Saccule

Contains about 16,000 hair cells

Sustained

Continuously monitoring some stimulus

Nonselective pathway

Contributes information about the distribution of features across a scene as well as information about the "gist" of the scene. This pathway does not pass through the bottleneck of attention

What happens in the sensory homunculus

Correspondence between pattern of two-point thresholds across body and relative distortion of different body parts in sensory homunculus sufficient concentration of receptors at the skin, each with small enough receptive field, that two contact points will elicit different responses

Ian Waterman

Cutaneous nerves connecting Waterman's kinesthetic mechanoreceptors to brain destroyed by viral infection Waterman lacks kinesthetic senses, which initially prevented him from walking or making virtually any motion. He has learned to imagine his movements and use his vision to help position his limbs.

Common hearing loss

Damage to hair cells due to excessive exposure to noise

Analgesia

Decreasing pain sensation during conscious experience Soldiers in battle: experience pain-relieving effect because of endogenous opiates, chemicals released in body to block release or uptake of neurotransmitters transmitting pain sensations to brain Externally produced substances have similar effect: Morphine, heroin, codeine

HSB color space

Defined by hue, saturation, and brightness - used in graphics design

Macular degeneration

Degeneration of the "macula": central vision, sharp details Loss in central vision --> blindness 1:3500 Canadians Typically leads to legal blindness by age 40 Caused by the formation of new veins or thinning of tissue. Rods die off first, leading to decay of cones

McGurk Effect

Demonstrates the cross-modal combination of auditory and visual information for speech perception Perception of onset consonants is determined by a combination of visual and auditory cues errors in binding can lead to illusory perception of consonants

Top-Down attention

Dependent on prior knowledge or task Determined by behavioral relevance Volition controlled Slower deployment

Directional transfer function

Describes how pinnae, ear canal, head, and torso change intensity of sounds with different frequencies that arrive at each ear from different locations in space (azimuth and elevation)

Gate control theory

Description of the system that transmits pain that incorporates modulating signals from the brain Feedback circuit located in substantia gelatinosa of dorsal horn of spinal cord Gate neurons that block pain transmission can be activated by extreme pressure, cold, other noxious stimulation applied to another site distant from source of pain

How do senses form in the environment?

Determined by the type of energy present in the environment

Staircase method

Determining concentration required for detection stimulus is presented in increasing concentrations until detection is indicated concentration is decreased until detection ceases repeated and reversals are averaged to determine threshold detection level

Shape pattern theory

Different scents activate different arrays of olfactory receptors in the olfactory epithelium as a function of odorant-shape to OR-shape fit These various arrays produce specific firing patterns of neurons in the olfactory bulb, which then determine the particular scent we perceive

Attentional blink

Difficulty in perceiving and responding to second of two target stimuli amid a RSVP stream of distracting stimuli

Overt

Directing a sense organ toward a stimulus, like pointing your eyes or turning your head

Sense of smell and language:

Disconnected, possibly because: Olfactory information is not integrated in thalamus prior to processing in cortex. Majority of olfactory processing occurs in right side of brain while language processing occurs in left side of brain.

Arthur Fox (1931)

Discovered that phenylthiocarbamide (PTC) tastes dramatically different to different people Bitter taste to some but not to others 1960s: started using propylthioracil (PROP) instead of pTC because it is safer Gene for PTC/PROP receptors discovered in 2003 individuals with two recessive genes are nontasters of PTC/PROP Individuals with one or more of the genes are tasters of PTC/PROP

Uncrossed disparity

Disparity created by objects behind the plane of the horopter images behind the horopter are displaced to the right eye and to the left in the left eye

Crossed disparity

Disparity created by objects in front of the plane of the horopter images in front of the horopter are displaced to the left in the right eye and to the right in the left eye

First-Order Motion

Displacement can be several degrees ISI can be as large as 500 msec Presentations can be monotopic or dicoptic Displaced patterns can have different contrasts Does not produce aftereffects

Second-Order motion

Displacement must be less than 1/4 degree ISI must be less than 100 msec Presentations must be monoptic Displacement patterns must have the same contrast Produces aftereffects

Autostereoscopic (3D)

Does not require any head gear

Protanopia

Due to absence of L cones

Tritanopia

Due to absence of S cones

Deuteranopia

Due to the absence of M cones

Why considered different "modalities" ?

Each involve different receptors and/or different stimulation energy

Two examples of "Simple Cells"

Edge detector and Stripe Detector

Ruffini Endings (SA II)

Embedded deeply in the dermis Responds best to sustained downward pressure and lateral skin stretch Responds to finger position and grasp Slowly adapting (SA II) Large receptive field size When stimulated people experience no tactile sensation. More than one SA II fiber need to be stimulated in order to be detectable

Pacinian Corpuscles (FA II)

Embedded in subcutaneous tissue Respond best to high frequency vibrations of 50-700 Hz Active when object makes first contact with skin, e.g. mosquito landing on skin, hitting key on keyboard Fast adapting (FA II) Large receptive field size When electrically stimulated, people report "buzz"

reflected

Energy that is redirected when it strikes a surface, usually back to its point of origin

synthesis

Example from color mixtures. Mixing red and green lights results in yellow light but we cannot separately perceive the red and green in the yellow

How do we know that listeners hear a sound as continuous?

Experiments that use signal detection task (e.g. Kluender and Jenison) suggest that at some point restored missing sounds are encoded in brain as if they were actually present

Smooth pursuit

Eye move smoothly to follow moving object (as with the pencil and dot demo)

Bottom-up

Factors from the world e.g. Looking for red and white to find Waldo

Top-down

Factors from you e.g. looking for waldo you won't look at the trees because people do not climb trees

V4 cells are interested in what?

Fans, spirals, and pinwheels

Correspondence Problem

Figuring out which bit of the image in the left eye should be matched with which bit in the right eye

Good continuation

Filling in of missing parts of sounds

Inner Ear

Fine changes in sound pressure are translated into neural signals Function roughly analogous to that of retina

Primary auditory cortex (A1)

First area within the temporal lobes of the brain responsible for processing acoustic organization

Cochlear nucleus

First brain stem nucleus at which afferent auditory nerve fibers synapse

Sir Alan Hodgkin and Sir Andrew Huxley

First scientists to record squid neurons

How would we identify a dog using categorization

First: Identify the superordinate animal Then we would identify the basic level which would be dog Then we would identify the subordinate level which is golden retriever And finally we would attribute an identity to the subordinate level which would be mr. Snuffles

Electrical stimulation of MT neurons (Newsome et al.)

Found direction sensitive MT neurons Stimulated them electrically while dots moved in nonpreferred direction Results: monkeys saw motion in the neurons preferred direction even when it was opposite to the direction of moving dots Conclusion: MT cells are global-motion detection area

Hubel and wiesel

Found systematic and progressive change in preferred orientation All orientations were encountered in a distance of about 0.5mm Same orientation preference in columns perpendicular to the surface of cortex

Common fate

Group elements in the same direction together

Proximity

Group things together that are closer together

Similarity

Grouping by timbre or by similar pitch

Push pull symmetry

Hair cells in opposite ears respond in a complementary fashion to each other When hair cells in the left ear depolarize, those in the analogous structure in the right ear hyperpolarize

Stereocilia

Hairlike extensions on the tips of hair cells in the cochlea that initiate the release of neurotransmitters when they are flexed

Cilia

Hairlike protrusions on the dendrites of OSNs. Contain receptor sites for odorant molecules. These are the first structures involved in olfactory signal transduction

Rod monochromat

Have no cones of any type; truly color-blind and badly visually impaired in bright light

Cone monochromat

Have only one cone type; truly color blind

Color-anomalous

Have two types of cones (typically L- and M-cones) which are so similar that they can't make discriminations based on them

What is one of the natural consequences of aging?

Hearing loss

What kind of frequency is absorbed?

High frequencies

Are more distant objects higher or lower in the visual field?

Higher

Spectral composition of sounds

Higher frequencies decrease in energy more than lower frequencies as sound waves travel from source to one ear (low frequencies travel farther)

Restoration of complex sound (E.g. music, speech)

Higher order sources of information, not just auditory information ECoG study: novel vs. nozzle presented as novel

Recent Human evidence suggests

Human olfaction is actually pretty good Elephants have 2000 ORs vs. Humans 400 Humans can track smells use odor to navigate, even out smell a mouse Humans need more molecules to smell whereas dogs need less

What has research shown when it comes to determining differences in sounds between two things

Humans are good at detecting small differences in frequency (as little as 1Hz between 999 Hz and 1kHz)

Yaw rotation thresholds

Humans are so sensitive to yaw rotation that we can detect movements of less than 1 degree per second At this rate, it would take 6 minutes to turn completely around As yaw rotation frequency decreases, it takes faster movement to be detected

Odor imagery

Humans have little or no ability to conjure odor "images" We do not think in smell very well We do not imagine smells very well - dreams with olfactory sensations are very rare Other animals for whom smell plays a more central role, such as rats, may very well think an dream smells...

Absorption

If Pigments A and B mix, some of the light shining on the surface will be subtracted by A, and some by B. Only the remainder contributes to the perception of color What remains is what is reflected

Illusion involving tilt perception

If you roll tilt your head to the left or right while looking at a vertical streak of light, the light appears to tilt in the opposite direction

Passive 3D

Images for the left and right eye are shown at the same time with differently polarized light Cheap passive glasses with polarization filters separate the images for the left and right eye Used in some 3D TVs and 3D cinema

Active 3D

Images for the left and right eye are shown in alternation Active shutter glasses block the view of the right and left eye in sync with the display used in some 3D Tvs

Pop-out or Parallel search

Immediate perception of oddball target, independent of set size

Why do we need attention?

Impossible to handle all sensory inputs at once. nervous system has evolved mechanisms to restrict processing to a subset of things, places, ideas, or moments

Coding of amplitude in the semicircular canals

In the absence of any rotation, many afferent neurons from the semicircular canals have a resting firing rate of about 100 spikes/s. This firing rate is high relative to nerve fibers in other sensory systems. High firing rate allows canal neurons to code amplitude by decreasing their firing rate, as well as increasing it. Changes in firing rate are proportional to angular velocity of the head aligned with the canal the neuron is in.

Suppression

In vision, the inhibition of an unwanted image

Neglect

Inability to attend to or respond to stimuli in the contralesional visual field (i.e. side opposite of brain lesion). typically after right parietal damage, leading to the inability to attend to one's left visual field

Tactile agnosia

Inability to identify objects by touch Caused by lesion to the parietal lobe (S1 and s2) Patient documented by Reed and cASELLI (1994) Could recognize weight and roughness on either hand Same sensory thresholds on both hands (how firm, how much motion, how much heat, etc.) But lacked a connection between sensation and recognition systems on the impaired side: Unable to integrate perceived properties about objects

Inanimate agnosia

Inability to recognize inanimate objects

end stopping

Increased firing rate as bar length increases, but once longer than receptive field, firing rate decreases

How do we estimate the time to collision of an approaching object?

Information source: Tau; It relies on information from retinal image -- need to track visual angle subtended by approaching object as it approaches the eye Not clear if we actually make use of tau, but: Humans are best at paying attention to the focus of expansion

How is stereopsis implemented in the human brain?

Input from two eyes must converge onto the same cell Many binocular neurons respond best when the retinal images are on corresponding points in the two retinas: Neural basis for the horopter However, many other binocular neurons respond best when similar images occupy slightly different positions on the retinas of the two eyes (tuned to particular binocular disparity)

ISI

Interstimulus Interval

What are the disadvantages of using lesion studies to study motion?

Invasive Lesions may be incomplete or may influence other structures

Contrast Sensitivity

Inverse of contrast threshold, e.g.: 1000-990 photons 1/0.01 = 100

Recognition-by-components (RBC) model

Irving Biederman proposed that objects are recognized by the identities and relationships of their component parts, called geons

How does image inversion affect facial recognition?

It hurts facial recognition more than object recognition

What happens when the IT cortex is lesioned?

It leads to agnosias in spite of the ability to see

What does adaptation provide strong evidence for with regards to spatial frequency?

It provides strong evidence that orientation and spatial frequency are coded by neurons in the human visual system

Which direction does the pathway for object recognition run?

It runs in both directions

Self-terminating search

Items examined one after another until target is found (target present) or until all items are checked (target absent)

mantis shrimp

Known for its amazing color perception with over 16 different photoreceptors 12 of those dedicated to color vision They can also see UV and long red wavelengths

Total stimulation of M cone is equal to Total stimulation of what?

L cone

Coding of amplitude in the otolith organs

Larger accelerations (or larger gravitation shear forces) move the otoconia more This leads to greater deflection of the hair cell bundles Change in receptor potential is proportional to magnitude of linear acceleration or gravitational shear

Physiology of ILDs

Lateral superior olives are neurons that are sensitive to intensity differences between two ears Excitatory connections to LSO come from ipsilateral (same side) ear inhibitory connections to LSO come from contralateral (opposite side) ear ILD works best for high frequencies...why?

Blurring the image

Leaving only the low-spatial frequency information (Reduces the number of blobs to match)

Photopic

Light intensities bright enough to stimulate cone receptors and bright enough to "saturate" the rod receptors Sunlight and bright indoor lighting are both photopic lighting conditions

The special case of fat

Like protein, fat is an important nutrient. Fat molecules evoke tactile sensations like oily, viscous, creamy, etc. Rats have fatty acid receptors on their tongues and humans may, too. Digesting fat in the gut produces conditioned preferences for the sensory properties of the food containing fat. New research says humans also have fat receptors

Merkel Cell Neutrite complex (SA I)

Located at boundary between epidermis and dermis Responds best to steady downward pressure Small receptive field size Used to detect fine spatial detail Sensitive to very low frequency of vibrations (< 5Hz) Slowly Adapting (SA I) Important for texture and pattern perception, e.g. for Braille reading or to determine the orientation of a screw head without looking When nerve is electrically stimulated, people report feeling "pressure"

Meissner Corpuscles (FA I)

Located at boundary between epidermis and dermis Sensitive to low frequency vibrations between 5 Hz and 50 Hz Fast adapting (FA I) Small receptive field size Important to detect slip of objects across skin, e.g. to correct grip around object When stimulated electrically, people feel "wobble" or "flutter"

Visual search

Looking for a target in a display containing distracting elements Target: the goal of visual search distractor: any stimulus other than the target Set size: the number of items in a visual display

Processes in object recognition

Low-level vision (Determine features present in image) Middle vision (Group features into objects) High-level vision (Match perceived to encoded representations)

Red+Blue

Magenta

Rate Intensity function

Map plotting firing rate of auditory nerve fiber in response to a sound of constant frequency at increasing intensities

Threshold tuning curve

Map plotting thresholds of a neuron or fiber in response to sine waves with varying frequencies at lowest intensity that will give rise to a response

Yarbus experiment

Mapped where people looked at an image and found that the eyes spent the most time looking at the eyes and mouth

Locating the haptic egocenter

Match the location of the right hand on top of the surface with the left hand on the bottom Results: Consistently err to the right - egocenter close to right shoulder change hands: egocenter appears to be at left shoulder

Method of Adaptation

Measuring the diminishing response of a sense organ to a sustained stimulus (without poking the brain)

Physiology of ITD

Medial superior olives are the first place where input converges from two ears ITD detectors form connections from inputs coming from two ears during first few months of life

Pleasant Touch

Mediated by unmyleniated peripheral C fibers known as "C tactile afferents" CT afferents not related to pain or itch Respond best to slowly moving, lightly applied forces (e.g. petting) Processed in orbitofrontal cortex (pleasure, reward)

Absolute Threshold

Minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time

Are receptive fields for extra striate area cells more sophisticated or less sophisticated than V1 cells?

More sophisticated than V1 cells

Subordinate-level category

More specific term for an object

sensorineural hearing loss

Most serious auditory impairment. Due to defects in cochlea or auditory nerve; when hair cells are injured ( e.g as result of ototoxic antibiotics or cancer drugs)

What do cortical cells respond well to?

Moving lines, bars, edges, gratings, and direction

Volley Principle

Multiple AN neurons can provide a temporal code for frequency if each neuron fires at a distinct point in the period of a sound wave but does not fire on every period

Fungiform papillae

Mushroom-shaped structures (maximum diameter 1 mm) that are distributed most densely on the edges of the tongue, especially the tip. An average of six taste buds per papilla are buried in the surface

Identity

Name for a specific object

Tipper and Behrmann's experiment on world vs. object based neglect:

Neglect can be object-based

Semicircular canal dynamics

Neural activity in semicircular canals is sensitive to changes in rotation velocity. Constant rotation leads to decreased responding from the canal neurons after a few seconds.

Topographical mapping

Neural basis for knowing where things are located in space (i.e., specific neural architecture for distinct locations in our visual field)

Why are we not bothered by variations in overall light levels?

Neural circuitry

Primary olfactory cortex

Neural region where olfactory information is first processed. Includes amygdala, parahippocampal gyrus, and entorhinal cortex

lateral superior olives

Neurons that are sensitive to intensity differences between two ears

Is speech an old or new structure

New structure in the cortex (Recent in evolution)

Do the vestibular organs respond to constant velocity?

No

is object recognition completely viewpoint invariant

No

Can each LGN cell respond to more than one eye?

No, it can only respond to one eye never both

Pain sensitization

Nociceptors provide signal when there is impending or ongoing damage to body's tissue "Nociceptive" pain Once damage has occured site can become more sensitive: Hyperalgesia Pain as result of damage to or dysfunction of nervous system: neuropathic No single pain medication will alleviate all types of pain

Dizziness

Nonspecific spatial disorientation

Is there a cortex for the vestibular system?

Not really areas of cortex respond to vestibular input as well as visual input

Pathway of nerves to cortex

Nucleus of the solitary tract in the brain stem, thalamus, cortex (insula, orbitofrontal)

Nonaccidental feature

Object feature not dependent on the exact (or accidental) viewing position of the observer. Provides clues to object structure (e.g. T junctions and occlusions)

Relative Height

Objects at different distances from the viewer on the ground plane will form images at different heights in the retinal image

The feel of scent

Odorants can stimulate somatosensory system through polymodal nociceptors (touch, pain, temperature receptors) These sensations are mediated by the trigeminal nerve (cranial nerve V) Often, it is impossible to distinguish between sensations travelling up cranial nerve I from olfactory receptors and those traveling up cranial nerve V from somatosensory receptors e.g.: peppermint - cool, ammonia, burning

Ternus effect

One circle appears to jump over a stationary circle in the center. Because the center circle remains perfectly stable it is not a possible candidate for apparent motion Identical to the previous one except a brief blank frame added between the two apparent motion frames. Display now perceived as two dots moving as a group

How do you measure visual acuity?

Optometrists use distance (e.g. 20/20; 6/6) Vision scientists use the smallest visual angle of a cycle of a grating

RGB

Outputs of long (red), medium (green), and short (blue) wavelength lights (monitors, projectors)

Alternating columns of pixels are projected into the two eyes using what?

Parallax barrier and lenticular arrays

Parallelism

Parallel contours are likely to belong to the same figure

Euclidian geometry

Parallel lines remain parallel as they are extended in space objects maintain the same size and shape as they move around in space internal angles of a triangle always add to 180 degrees

Decay (sound)

Part of a sound during which amplitude decreases (offset)

Matching

Participants are tilted and then orient a line with the direction of gravity. This is done in a dark room with only the line visible to avoid any visual cues to orientation

What happens when we cannot perceive taste but we can perceive smell?

Patient case: damaged taste, but normal olfaction -- could smell lasagna, but had no flavor similar effect created in lab: chorda tympani anesthetized with lidocaine

retronasal olfaction

Perceiving odors through your mouth while breathing and chewing. This occurs when we are smelling something that is inside our mouth and is what gives us the experience of flavor.

tilt aftereffect

Perceptual illusion of tilt, provided by adapting to a pattern of a given orientation suggests human visual system contains individual neurons selective for different orientations

Selective pathway

Permits the recognition of one or a very few objects at a time The pathway passes through the bottleneck of selective attention

Temporal code for sound frequency

Phase Locking: Neuron fires only at a distinct point in the period (Cycle) of sound wave at given frequency AN fibers fire with a temporal code

Cones

Photoreceptors that are specialized for daylight vision, fine visual acuity and color

Kinesthetic receptors

Play important role in sense of where limbs are, what kinds of movements are made spindles, receptors in tendons, and receptors in joints

Phase

Position of grating within a receptive field

What are two ways to study the vision of infants?

Preferential-looking paradigm Visual evoked potentials

Gestalt grouping rules

Principles for grouping the seemingly

Temporal integration

Process by which a sound at a constant level is perceived as being louder when it is out of greater duration

Reflectance Curve

Proportion of light at different wavelengths that is reflected from a pigment

The vestibular organs help us in many ways, for instance:

Provide a sense of spatial orientation Linear motion Angular motion Tilt Allow for the vestibulo-ocular reflex Stabilizes visual input by counter rotating the eyes to compensate for head movement

Nonmetrical

Provides information about the depth order (relative depth) but not depth magnitude (e.g. his nose is in front of his face)

Metrical

Provides quantitative information about distance in the third dimension (e.g. the tip of his nose is 3.2 cm from his cheek)

What physical property is color?

Psychophysical

Reaction time benefit of the cue

RT (invalid) - RT (valid)

The efficiency of visual search is the average increase in

RT for each item added to the display

Saccade

Rapid movement of eyes that change fixation from one object or location to another

Cyclopean

Referring to stimuli that are defined by binocular disparity alone

Contralateral

Referring to the opposite side of the body/brain

Dichoptic

Referring to the presentation of two stimuli one to each eye. Different from binocular presentation, which could involve both eyes looking at a single stimulus

Extra striate cortex

Region of cortex bordering the primary visual cortex and containing multiple areas involved in visual processing Respond to visual properties important for perceiving objects

Parallelism

Regions with parallel contours tend to be seen as figure

Simplest Cue

Relative intensity of sound

Categorical perception of consonants (onsets)

Researchers can manipulate sound stimuli to vary continuously from "bah" to "dah" to "gah" People perceive sharp categorical boundaries between the stimuli instead of perceiving sounds as continuously varying

Parahippocampal place area

Responds preferentially to places, such as pictures of houses or landscapes

Fusiform face area

Responds to faces more than other objects

Auditory Nerve

Responses of individual auditory nerve fibers to different frequencies related to position along cochlear partition

LMS

Responses of the three types of cones

S1 and S2

Responsible for sensory aspects of pain

What does interocular transfer tell us about the locus of the MAE in the visual system?

Result of activities of neurons in a part of the visual system where information collected from two eyes is combined Input from both eyes is combined in area V1 Recent studies: localized motion aftereffects to MT

Motion sickness

Results when there is a disagreement between the motion and orientation signals provided by the semicircular canals, otolith organs, and vision

How do we recognize objects?

Retinal ganglion cells and LGN = Spots Primary Visual Cortex = Bars

What does S1 connect to

S2

David Hubel and Torsten Wiesel

Sensation and perception; Discovered feature detectors, groups of neurons in the visual cortex that respond to different types of visual stimuli Their experiment was performed on a cat

Thermoreceptors

Sensory receptors that signal information about changes in skin temperature Two distinct populations of thermoreceptors: warmth fibers, cold fibers

Nociceptors

Sensory receptors that transmit information about noxious (painful) stimulation that causes damage or potential damage to the skin Two groups of nociceptors

Gunnar Svaetichin

Showed the existence of three different cone types with different sensitivity to wavelength in 1956

Inverse-square law

Sound intensity decreases with 1/d2 with increasing distance d in 3D space

Outer ear

Sounds are first collected from the environment by the pinnae sound waves are funnelled by the pinna into ear canal length and shape of ear canal enhance sound frequencies main purpose of canal is to protect the tympanic membrane (eardrum)

Summerfield experiment

Sounds with holes in the spectrum, presented right before a uniform spectrum. The uniform spectrum is heard as a vowel

What happens when vestibular system fails?

Spatial disorientation Imbalance Distorted vision unless head is held perfectly still Motion sickness Cognitive problems

Problems that can arise from the vestibular system

Spatial disorientation dizziness Vertigo Imbalance Blurred vision Illusory self-motion

Middle Temporal Area (MT)

Specialized for motion processing

Extrastriate Body Area (EBA)

Specifically involved in the perception of body parts

Glomeruli

Spherical conglomerates containing the incoming axons of the OSNs Each OSN converges on two glomeruli (one medial, one lateral)

Cochlea

Spiral structure of inner ear containing the organ of corti filled with water fluids in three parallel canals vestibular canal: oval window to helicotrema Tympanic canal: round window to helicotrema middle canal: contains the cochlear partition

Divided

Splitting attention between two different stimuli

SOA

Stimulus Onset Asynchrony

Exotropia

Strabismus in which one eye deviates outward

tip links

Structures at the tops of the cilia of auditory hair cells, which stretch or slacken as the cilia move, causing ion channels to open or close. open potassium channels leading to depolarization

Pigments

Substances that absorb light at some wavelengths and reflect light at others

Five relational violations according to Biederman et al. (1982)

Support Interposition Probability Position Size

Three types of cells

Supporting cells Basal cells olfactory sensory neurons

Mal de Debarquement Syndrome

Swaying, rocking, or tilting perceptions felt after spending time on a boat or in the ocean Aftereffect of adapting to the rocking motion of the ocean "Getting your sea legs" Usually goes away after a few hours, but some people experience it continuously, causing problems

Symmetry

Symmetrical regions are more likely to be seen as figure

DCML

Synapse in cuneate and gracile nuclei, then ventral posterior nucleus of thalamus then somatosensory area 1 (S1), somatosensory area 2 (S2) Wider axons fewer synapses faster information transmission used for planning and execution of fast movements

Symbolic (Endogenous) cue

Target location derived indirectly from shape or color of cue

Adam Magyar

Techno artist and photographer who uses a special scanning technique to combine thousands of pixel-wide slices into a single image He confouds time and space in his images Motion parallax clearly visible

Deep learning computer vision models

Template (view-based) theory Massive set of increasingly complex features Works amazing well Matches neural representations in visual brain areas

Closure

Tendency to see complete figures or forms even if a picture is incomplete, partially hidden by other objects

Apparent motion

The (illusory) impression of smooth motion resulting from the rapid alternation of objects appearing in different locations in rapid succession First demonstrated by Sigmund Exner in 1875 Motion detector circuit does not need real motion in order to fire The basis for flop books, movies, TV

Vanishing point

The apparent point at which parallel lines receding in depth converge

fundus

The back layer of the retina—what the eye doctor sees through an ophthalmoscope.

Receptor Adaptation

The biochemical phenomenon that occurs after continuous exposure to an odorant, whereby the receptors stop responding to the odorant and detection ceases

Hue

The chromatic (Color) aspect of light

Pupil

The dark circular opening at the center of the iris in the eye, where light enters the eye

interaural level difference (ILD)

The difference in level (intensity) between a sound arriving at one ear versus the other

Interaural time difference (ITD)

The difference in time between a sound arrive at one ear versus the other

Binocular disparity

The differences between two retinal images of the same scene Differences as small as .005mm can be detected

Empiricism

The idea that all knowledge comes through the senses

Level of response depends on what when talking about cones?

The level of response depends on lighting conditions

olfactory sensory neurons (OSNs)

The main cell type in the olfactory epithelium OSNs are small neurons located beneath a watery mucous layer in the epithelium We have approximately 5-10 million OSN. Only vision has more sensory neurons (photoreceptors)

Nativism

The mind produces ideas that are not derived from external sources, and that we have abilities that are innate and not learned

Two-point threshold

The minimum distance at which two stimuli (e.g. two simlutaneous touches) are just perceptible as separate

Angular VOR

The most well-studied VOR example when the head turns to the left, the eyeballs are rotated to the right to partially counteract this motion

Second order motion

The motion of an object that is defined by changes in contrast or texture, but not by luminance

Medial geniculate nucleus

The part of the thalamus that relays auditory signals to the temporal cortex and receives input from the auditory cortex

trichromacy

The perceived color of any light is defined in our visual system by the relationships between a set of three numbers, the outputs of three receptor types now known to be the three cones

Missing-fundamental effect

The pitch listeners hear corresponds to the fundamental frequency, even if it is missing

Correspondence problem (motion)

The problem faced by the motion detection system of knowing which feature in frame 2 corresponds to a particular feature in frame 1 There are a wide variety of Gestalt principles that can influence the brain's solution to the correspondence problem: 1. proximity 2. color 3. shape

Preattentive stage

The processing of a stimulus that occurs before selective attention is deployed to that stimulus (automatically)

Global superiority effect

The properties of the whole object take precedence over the properties of parts of the object (e.g. Navon letters)

Naive template theory

The proposal that the visual system recognizes object by matching the neural representation of the image with a stored representation of the same "shape" in the brain

blood oxygen level-dependent (BOLD) signal

The ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain neurons that are most involved in a task

Cross Adaptation

The reduction in detection of an odorant following exposure to another odorant presumed to occur because the two odors share one or more olfactory receptors for their transduction, but the order of odorants also plays a role

Receptive Field

The region in space in which stimuli will activate a neuron

Olfactory Receptor (OR)

The region on the cilia of OSNs where odorant molecules bind It takes seven or eight odor molecules binding to a receptor to initiate an action potential It takes about 40 such events to perceive an odor

Although the eyeball is mostly similar to how a camera functions, how isn't the eyeball similar?

The resemblance stops at the retina where transduction occurs. However, the regulation of the amount of light and the lens for adjusting focal length for viewing near and far objects are similar to that of a camera

Sensation

The result of physical interaction between the world and our bodies

Size

The smaller region is likely to be figure

Cristae

The specialized detectors of angular motion located in each semicircular canal in a swelling called the ampulla Each crista has about 7000 hair cells, associated supporting cells, and nerve fibers Cilia of hair cells project into jellylike cupula which forms an elastic dam extending to the opposite ampulla wall, with endolymph on both sides of the dam

Psychoacoustics

The study of the psychological correlates of the physical dimensions of acoustics; a branch of psychophysics

Surroundedness

The surrounding region is likely to be ground

Vieth-Muller circle

The theoretical location of objects whose images fall on geometrically corresponding points in the two retinas in the horizontal plane. Circle that intersects the objects and the lenses of both eyes. Based on geometry of location of eyes

Opponent color theory

The theory that perception of color is based on the output of three mechanisms, each of them based on opponency between two colors

Trichromacy

The theory that the color of any light is defined in our visual system by the relationships of three numbers, the outputs of three receptor types now known to be the three cones

Semicircular canals

The three toroidal tubes in the vestibular system that sense angular acceleration, a change in angular velocity each one is about 3/4 of a toroid (donut) shape, measuring 15mm long and 1.5mm in diameter Canals are filled with a fluid called perilymph A second smaller toroid is foiund inside the larger toroid, measuring 0.3mm in diamter Formed by a membrane filled with fluid called endolymph cross section of each canal swells substantially near where the canals join the vestibule: ampulla

cornea

The transparent "window" into the eyeball (No blood vessels, has nerves)

vitreous humor

The transparent fluid that fills the vitreous chamber in the posterior part of the eye 80% of the volume of the eye

Aqueous humor

The watery fluid in the anterior chamber

How are human senses limited?

They are limited to only certain kinds of energy in the environment

Why does an oriented grating appear to be gray if you are far enough away?

This striped pattern is a "sine wave grating"; the visual system "samples" the grating discretely

Coding of direction in the semicircular canals

Three semicircular canals in each ear Each canal is oriented in a different plane Each canal is maximally sensitive to rotations perpendicular to the canal plane

Three experimental paradigms are typically used to investigate spatial orientation perception

Threshold estimation, magnitude estimation, matching

Tadoma method of speech perception for deaf and blind people

Thumb on speaker's lips, fingers along the jawline, little finger feels vibrations of the throat Invented by American teacher Sophi Alcorn Named after the first two children who used the method: Winthrop "Tad" Chapman and Oma Simpson

Stimulus onset asynchrony (SOA)

Time between the onset of one stimulus and the onset of another

Cochlear implants

Tiny flexible coils with miniature electrode contacts Surgeons thread implants through round window toward cochlea apex Tiny microphone transmits radio signals to a receiver in the scalp Signals activate minature electrodes at appropriate positions along the cochlear implant Activated electrodes stimulate the auditory nerves

Anosmia

Total inability to smell, most often resulting from sinus illness or head trauma A hard blow to the front of the head can cause the cribriform plate to be jarred back or fractured, slicing off the fragile olfactory neurons Anosmia also causes a profound loss of taste can lead to depression, loss of libido Anosmia can be an early signal for the onset of Alzheimer's or Parkinson's Disease

Jack Loomis experiment

Touch acts like blurred vision when the fingertips explore a raised pattern 1. Visual stimuli blurred to match the acuity of fingertip skin 2. Visual stimuli and haptic stimuli showed same confusion errors

Thomas Young and Hermann von Helmholtz

Tri-chromatic theory/tri-color/component theory

Two caveats for theory that odor hedonics are mostly learned

Trigeminally irritating odors may elicit pain responses, and all humans have an innate drive to avoid pain There is potential variability in receptor genes and pseudogenes that are expressed across individuals

Opponent Reichardt Motion Detector

Two Reichardt detectors tuned to opposite directions of motion. Outputs are subtracted from one another.

Common region

Two features will group if they appear to be apart of the same larger region

Connectedness

Two items will tend to group if they are connected

How many steps does face perception proceed in?

Two steps

Binding

Tying multiple features of a stimulus to a unified object requires attention

Middle Ear

Tympanic membrane is border between outer ear (ear canal) and middle ear consists of three tiny bones, ossicles that amplify sounds Ossicles

Vergence eye movement

Type of eye movement in which two eyes move in opposite directions, done deliberately for spatial vision

How finely can we resolve temporal details?

Typical resolution found 5ms Common psychophysical method: decide whether two events are simultaneous or sequential This is better than vision (25ms) but worse than audition (0.01ms)

Harmonic Spectra

Typically caused by simple vibrating source (e.g. string of guitarm or reed of saxophone) fundamental frequency

Anamorphosis (or anamorphoic projection)

Use of rules of linear perspective to create a two dimensional image so distorted that it looks correct only when viewed from a special angle or with a mirror that counters the distortion Opposite of the accidental viewpoint

Landolt Rings (or "Cs")

Used in most European countries, a way to determine visual acuity that does not involve the prior knowledge of letters

Azimuth

Used to describe locations on imaginary circle that extends around us, in a horizontal plane

Masking

Using a second sound, frequency noise, to make the detection of another sound more difficult; used to investigate frequency selectivity

How is stereoacuity often tested

Using dichoptic stimuli

What is S1 equivalent to

V1 in vision or A1 in hearing

Why don't people feel as if they are turning upside down

Vestibular system's sense of gravity stops the illusion Astronauts without gravity feel as if they are tumbling under these circumstances Thus vestibular information is combined with visual information to yield a "consensus" about our sense of spatial orientation

Ambiguous Figure

Visual stimulus that gives rise to two or more interpretations of its identity or structure

What experiments demonstrated the cone of confusion

Wallach (1940)

Detection

Wavelengths of light must be detected in the first place

Tilt Perception

We are very accurate when perceiving tilt for angles between 0 degrees (upright) and 90 degrees (lying down)

Discrimination

We must be able to tell the difference between one wavelength (or mixture of wavelengths) and another

Appearance

We want to assign perceived colors to lights and surfaces in the world and have those perceived colors be stable over time, regardless of different lighting conditions

What does 20/20 vision mean?

What a person with perfect vision can see at 20 feet, you can also see at 20 feet Distance at which patient can identify the letters/distance at which a person with "normal" vision can identify the letters

After extra striate cortex, object information processing is split into what two pathways?

What pathway Where pathway

Hyperopia

When light entering the eye is focused behind the retina; farsightedness

Translation perception

When people are passively translated in the dark, they are able to use a joystick to reproduce the distance they traveled quite accurately Interestingly, they also reproduce the velocity of the passive-motion trajectory The otolith organs register acceleration, and our brains mathematically integrate the acceleration and turn it into the perception of linear velocity

Grouping by onset

When sounds begin at the same time, or nearly the same time, they appear to be coming from the same sound source This helps group different harmonics into a single complex tone Consistent with Gestalt law of common fate

pupil dilation

When the pupils in the eyes expand to look large adjusting light intake

Cross-adaptation

When the taste of one food affects the taste of another Example: A sour beverage taste too sour after eating something sweet

When do people react faster

When there is a valid cue compared to an invalid cue

Can each striate cortex cell can respond to more than one eye?

Yes, it can respond to input from both eyes (with preference for one eye's input: ocular dominance)

Human embryos may have what

a VNO that may disappear shortly after birth

Typical light sources emit

a broad spectrum of wavelengths 400-700nm

off center ganglion cell

a cell that increases firing in response to a decrease in light intensity in its receptive field center

somatosensation

a collective term for sensory signals from the body (also includes vestibular system)

RGB space

a cube, with white and black as diagonally opposite corners

Pictorial depth cue

a cue to distance or depth used by artists to depict three-dimensional depth in two dimensional pictures

linear perspective

a depth cue based on the fact that lines that are parallel in the three-dimensional world will appear to converge in a two dimensional image

degrees of visual angle

a function of both objects actual size and distance from the observer

Pointilism

a genre of painting characterized by the application of paint in dots and small strokes Additive color mixtures are achieved by placing dots of different colors in close proximity to each other, rather than subtractive mixtures that are obtained when pigments are mixed together in the same location

attention

a large set of selective processes in the brain that can pick one out of many stimuli make us more (or less) sensitive to stimulation Select "slices" of time or space resolve perceptual ambiguity exist in every modality

sound waves

a longitudinal wave consisting of compressions and rarefactions, which travels through a medium

lateral geniculate nucleus

a place in the thalamus that receives impulses from the optic nerve

Orbitofrontal cortex

a region of the brain in which impulses involving excretion, sexuality, violence, and other primitive activities normally arise

Preferential-looking paradigm

a research technique to explore early infant sensory capacities and cognition, drawing on the principle that we are attracted to novelty and prefer to look at new things Infants prefer to look at more complex stimuli

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

Anechoic chamber

a room designed to completely absorb reflections of sound waves

spatial orientation

a sense comprised of three interacting sensory modalities angular motion, linear motion, and tilt

Frame of reference

a system of objects that are not moving with respect to one another

tympanic membrane

a thin sheet of skin at end of outer ear canal. It vibrates in response to sound Common myth - puncturing your eardrum will leave you deaf in most cases it will heal itself it is possible to damage it beyond repair

tuning fork

a two-pronged, fork-like instrument that vibrates when struck; used to test hearing, especially bone conduction

Accidental Viewpoint

a viewing position that produces some regularity in the visual image that is not present in the world

stereopsis

a vivid perception of the three-dimensionality of the world that is not available with monocular vision

longitudinal waves

a wave in which the particles of the medium vibrate parallel to the direction of wave motion

Echo localization or echolocation

ability of some animals to detect the presence and location of object by the reflection of a self-produces sound

Bitter

about 25 different bitter receptors in humans quinine: prototypically bitter-tasting substance cannot distinguish between tastes of different bitter compounds many bitter substances are poisonous Ability to "turn off" bitter sensations--beneficial to liking certain vegetables Bitter sensitivity is affected by hormone levels in women, intensifies during pregnancy

what is a good way of finding out with alive humans what the visual system is sensitive to?

adaptation

Dithering makes use of what

additive color mixing, both in print and on displays

food industry

adds sugar to intensify sensation of fruit juice increase in sweetness (a pure taste sensation) increases perceived olfactory sensation of fruit

adjacent areas on skin are connected to what

adjacent areas in brain

Hering's opponent-process theory

after image in opposite colors (RG, YB)

Taste adaptation

all sensory systems show adaption effects constant application of certain stimulus temporarily weakens subsequent perception Example: adaptation to salt in saliva affects our ability to taste salt

intensity

amount of sound energy falling on a unit area

Ossicles have hinged joints that work like levers to what

amplify sounds

Physical qualities of sound waves include

amplitude, intensity, and frequency

cytochrome oxidase blobs

an area of primary visual cortex rich in the enzyme cytochrome oxidase that responds to color

patch clamp

an extraordinarily sensitive voltage clamp method that permits the measurement of ionic currents flowing through individual ion channels

Reflexive eye movement

an eye movement that is automatic and involuntary

vection

an illusory sense of self motion produced when you are not in fact, moving

Aperture

an opening that allows only a partial view of an object

What does an ILD generally correlate with

angle of sound source, but correlation is not quite as great as it is with ITDs

Spatial disorientation

any impairment of spatial orientation (i.e. our sense of linear motion, angular motion, or tilt)

opponent processes

any process which functions as the antagonist of another process

Odorant

any specific aromatic chemical chemical compounds but not every chemical is an odorant In order to be smelled, molecule must be: Volatile (able to float through air), small, hydrophobic (water repellant)

tastant

any stimulus that can be tasted

Nature or nurture for olfactory hedonics?

are hedonic responses to odors innate or learned evidence from infants: odor preferences often very different from adults cross-cultural data support associative learning an evolutionary argument: some animals exhibit an instinctive aversion to smells from predators Learned taste aversion: Avoidance of a novel flavor after it has been paired with gastric illness

Lateral intraparietal cortex

area in posterior parietal cortex involved in planning and executing eye movements

Anamorphic Art

art that stretches an object into a distorted form that can only be recognized by turning the canvas at a different angle.

How far do touch sensations travel

as far as 2 meters to get from skin and muscles of feet to brain Information must pass through spinal cord (first synapse) Axons of various tactile receptors combine into single nerve trunks Several nerve trunks from different areas of body

Where is the ILD the largest

at 90 degrees and -90 degrees

where are sounds more intense

at the ear closer to the sound source

feature search

attend to one feature dimension Flat search slope, parallel search, efficient search target presence or absence does not affect response time no need for binding

Feature-based attention

attention can enhance the processing of a specific feature which can lead to different perceptions

Zoom lens model

attention expands from fixation, grows to fill whole region, shrinks to include just cued location

object-based attention

attention that is directed to a specific object Attention spreads across objects

vestibulo-autonomic responses

autonomic nervous system Motion sickness

Primary Visual Cortex processes

bars

sine gratings

basic stimulus used in linear systems Visual system breaks down images into sine wave gratings with a particular spatial frequency ("Fourier analysis") Edges of objects produce a single stripe in the retinal image

Hyperpolarization

bending away from tallest stereocilia

Depolarization

bending toward tallest stereocilia

Where is a large proportion of processing done in the visual system?

beyond V1

Balint syndrome

bilateral lesion of parietal lobes 1. Reduced spatial localization abilities 2. Reduced movement of the eyes 3. Inability to perceive more than one object at a time (simultagnosia) 4. Inability to bind features correctly into objects

Brain imaging studies

brain processes odors differently depending on whether they come from nose or mouth

combinatorial code

brain uses the pattern of firing rates across fibers to determine frequency about 1400 fibers in each ear to describe each pattern

How does the motor system solve the problem of why an object in motion may appear stationary ?

by sending out two copies of each command to move eyes One copy goes to eye muscles to move the eye another called the efferent copy goes to an area of the visual system called the comparator

tilt

can be sensed when nodding head up and down as if to say "yes"

angular motion

can be sensed when rotating head from side to side as if to say "no"

Familiar size

can provide precise metrical information if your visual system knows the actual size of the object and the visual angle it takes up on the retina

conductive hearing loss

caused by problems with the bones of the middle ear

Cells with receptive fields that have

center-surround organization

Optic flow

changing angular position of points in perspective image that you experience as you move through the world

congential anosmia

children often pretend to be able to smell

Chili peppers

chilli pepper preference depends on social influences liking unique to humans individuals vary, depends on number of papillae Caapsaicin: chemical in chilis that produces burn. desensitizes pain receptors

What three nerves carry taste information

chorda tympani, glossopharyngeal nerve, vagus

Circumvallate papillae

circular structures that form an inverted V on the rear of the tongue (three to five on each side) Mound like structures surrounded by a trench. Much larger than fungiform papillae

Discriminative touch

classic touch sensations of tactile, thermal, pain, and itch experiences

Cataract

clouding of the lens

What does color provide in ambiguous apparent motion matches

color provides a slight bias to perceive horizontal motion, though it easily overridden with attention

white light

combination of all colors

What do you require when hearing complex sound

combinatorial code

Comparator

compensates for image changes caused by eye movement - inhibits rest of visual system interpreting changes as object motion

Binaral rivalry

competition between the two nostrils for odor perception When a different scent is presented to each nostril, we experience one scent at a time, not a combination of the two scents together

Where pathway

concerned more with locations and shapes of objects

What pathway

concerned more with names and functions of objects

Newsome and Pare study

conducted a study on motion perception in monkeys Trained monkeys to respond to correlated dot motion displays The MT area of the monkeys was lesioned result: monkeys needed about ten times as many dots to correctly identify direction of motion

White noise

consists of all audible frequencies in equal amounts; used in masking

utricle

contains about 30,000 hair cells

What does the brain contain regarding maps and subareas

contains several sensory maps of body, different subareas of S1, and secondary areas as well

what was the effect of the lesion in the newsome and Pare study

contralateral

Transduction

conversion of one form of energy into another

Inner hair cells

convey almost all information about sound waves to brain

outer hair cells

convey information from brain (use of efferent fibers) They are involved in elaborate feedback system when stiff can suppress noise when less stiff, can tune to a given frequency

spindles

convey the rate at which the muscle fibers are changing in length

Y junctions indicate

corners facing the observer

vestibulo-ocular reflexes (VORs)

counter-rotating the eyes to counteract head movements and maintain fixation on a target

Vestibulo-ocular reflexes (VORs)

counter-rotating the eyes to counteract head movements and maintain fixation on a target Angular VOR Torsional eye movements

glossopharyngeal nerve

cranial nerve IX for the middle part of the tongue

visual cliff experiment

created by E.J. Gibson, used to determine when infants can perceive depth If babies do not walk across the cliff then they understand depth cues if they do walk across the visual cliff they do not understand depth cues

How is sound created?

created when objects vibrate vibrations of an object cause molecules in the object's surrounding medium to vibrate as well, which causes pressure changes in the medium

Taste buds

creates neural signals conveyed to brain embedded in structures: papillae (bumps on tongue) each taste bud contains taste receptor cells information is sent to brain via cranial nerves

ampulla

cross section of each canal swells substantially near where the canals join the vestibule

Blue+Green

cyan

two tone suppression

decrease in AN fiber firing rate when two tones presented at similar frequencies at same time

Visual Crowding

deleterious effect of clutter on peripheral object detection Stimuli seen in isolation in peripheral vision are hard to discern when other stimuli are nearby Major bottleneck for visual processing When we can't see an object due to crowding, we have to move our eyes to look directly at it with our high acuity foveal receptive fields

James Clerk Maxwell

demonstrated that light consists of two transverse waves oscillating at right angles to each other

Sound waves travel at a particular speed

depends on medium example: speed of sound through air is about 340 meters/second, but speed of sound through water is 1500 meters/second Light travels a million times faster than sound

It takes time for the cue to be processed and for attention to be

deployed

Accommodation and convergence help perception of what?

depth

Familiar size

depth cue based on knowledge of the typical size of objects

Optic array

describes collection of light rays that interact with objects of the world in front of viewer

L cones

detect long wavelengths 565 nm Red Cones

M Cones

detect medium wavelengths 535 nm Green Cones

parvocellular cells

detect shape - have very high colour spatial resolution

S cones

detect short wavelengths 420nm Blue cones

Contrast

difference in illumination between a figure and its background

Olfactory receptor cells

different from all other sensory receptor cells: Not mediated by protective barrier, make direct contact with the brain Visual receptors protected by cornea, hearing receptors protected by eardrum, taste buds buried in papillae Many drugs can be inhaled OSN axons are thin and slow It takes longer to perceive odors compared to other sense, around 400 ms, compared to 45 ms for visual stimulus to reach the brain

Metamers

different mixtures of wavelengths that look identical More generally, any pair of stimuli that are perceived as identical in spite of physical differences

Temporal code

different parts of the cochlea respond to different frequencies, in which information about the particular frequency of an incoming sound wave is coded by the timing of the neural firing as it relates to the period of soudn -firing every 0.01 seconds (phase) => frequency of sound is 1/0.01 = 100 Hz But limited to soudns <1000Hz (AN fibers can only fire so frequently)

Scotopic

dim light levels at or below the level of bright moonlight rods are sensitive to scotopic light levels All rods contain same photopigment: rhodopsin All rods have same sensitivity to wavelength, making it impossible to discriminate light

Peripheral (exogenous) cue

directly indicates target location

Ernst Weber

discovered that the smallest change in a stimulus that can be detected is a constant proportion of the stimulus level known as Weber's Law

tricky problem (motion)

discriminating motion across the retina that is due to eye movements vs object movements Our visual perception is generally stable in spite of constantly moving eyes... how?

What do relative amounts of direct versus reverberant energy also help us evaluate?

distance

eccentricity

distance from the fixation

Deleting midsections but not vertices does what?

does not hurt identification

Ambiguous display

dots can appear to move vertically or horizontally

Contrast sensitivity varies

dramatically among different species

Gustav Fechner

early German psychologist credited with founding psychophysics and often coined the founder of experimental psychology

Some complex features like depth cues can lead to what

efficient, pop-out searches others require attention to bind together multiple features

magnocellular layer

either of the bottom two neuron-containing layers of the lateral geniculate nucleus, the cells of which are physically larger than those in the top four layers Contains the Parasol system and is adapted for fast, large moving objects

Visual evoked potentials

electrical signals from the brain that are evoked by visual stimuli

Touch receptors

embedded in outer layer (epidermis) and underlying layer (Dermis)

Secondary pain effect

emotional response associated with long term suffering (e.g. cancer patients undergoing chemotherapy)

refracted

energy that is altered as it passes into another medium (e.g. light entering water from the air)

transmitted

energy that is passed on through a surface (when it is neither reflected nor absorbed by the surface)

absorbed

energy that is taken up and not transmitted at all

selective adaptation

evidence that human visual system contains neurons selective for spatial frequency

sweet

evoked by sugars many different sugars that taste sweet glucose: principle source of energy for most animals fructose: even sweeter than glucose sucrose: common table sugar. Combination of glucose and fructose Single receptor responsible for all sweet perception different sweeteners stimulate different parts of the receptor artificial sweeteners stimulate this receptor

Odors appear to be the most potent stimulus for what

evoking memories of previous encounters with the odor other modalities such as vision and taste can also elicit memory memories triggered by odor cues are distinctive in their emotionality Emotion and evocativeness of odor-elicited memories lead to false impression that such memories are especially accurate

analyses

example from auditory mixtures. High note and low note can be played together but we can detect each individual note

Continuity constraint

except at the edges of objects, neighboring points in the world lie at similar distances from the viewer

action for perception

exploratory procedure: stereotyped hand movement pattern used to contact objects in order to perceive their properties Optimal for obtaining precise details about one or two specific properties

Saccades

eyes move at up to 1000 degrees/ second we make about 3 to 4 saccades per second That's 172,800 saccades every day Saccades go to places of "interest"

Change blindness

failure to notice change between two scenes; perception depends on meaning of change

Things really close will move what?

fast

A delta fibers

fast transmission to brain, respond to strong pressure (crushing) and heat initial and quick sharp burst of pain at injury time

Dorsal column medial lemniscal

faster tactile and proprioceptive information, fewer synapses = fast transmission

Wilhelm Wundt

father of experimental psychology, first person to call himself a "psychologist", Founded the first formal laboratory for Psychology in Leipzig, Germany

A symmetrical region tends to be seen as

figure

primary function of nose

filters, warms, humidifies air we breathe Contains small ridges, olfactory cleft, and olfactory epithelium

Olfactory nerves

first pair of cranial nerves. Axons of OSNs bundle together after passing through cribriform plate to form the olfactory nerve

inner ear consists of

fluid filled chamber. it takes more energy to move liquid than air

Foliate papillae

folds of tissue containing taste buds. Located on the rear of the tongue lateral to the circumvallate papillae, where the tongue attaches to the mouth

Why is their color vision in animals

for food and sex foraging for colored food is easier advertisements for bees to trade food for sex (pollination) colorful patterns on tropical fish and toucans provide sexual signals (better health, genes)

frequency

for sound, the number of times per second that a pattern of pressure repeats

chorda tympani

for the most anterior part of the tongue (branch of the facial nerve, cranial nerve VII)

doctrine of specific nerve energies

formulated by Johannes Muller, stating that the nature of a sensation depends on which sensory fibers are stimulated, not on how fibers are stimulated

How many colors did Hering use

four basic colors

cones are concentrated in the

fovea

Rods are concentrated in the

fovea centrails

Drift, tremor, and microsaccades keep the image

fresh

Tectorial membrane

gelatinous structure attached on one end, extends into the middle canal, floats above inner hair cells and touches outer hair cells vibrations cause displacement of the tectorial membrane, which bends stereocilia attached to hair cells and causes the release of neurotransmitters

geons

geometric ions

efferent copy

goes to an area of visual system called the comparator

Are subjects good or bad ant indicating how much they are tilted

good

ganglion cells respond differently to what?

gratings of different spatial frequencies

In order for a mixture of a red light and a green light to look perfectly yellow, you have to add just the right amount of red and just the right amount of what

green

synchrony

group elements changing at the same time

Preattentive features can do what?

guide attention to likely places where the target can be More efficient search lens processing of sensory information

What do hair cells in the vestibular system do

hair cells increasing firing to rotation in one direction and decrease firing to rotation int he opposite direction

What are material properties of objects most important for?

haptic recognition

timbre

harmonic structure of sounds sounds with the same intensity and fundamental frequency can still be perceived as different, this is related to differences in timbre

Cone photoreceptors

have a shorter, tapering outer segment with fewer membranous disks

Torsional eye movements

head is rolled about the x axis, the eyeballs can be rotated a few degrees in the opposite direction to compensate

Angular VOR

head is rotated, eyes maintain fixation

Amplification provided by the ossicles is essential to our ability to what?

hear faint sounds

What is an older sense

hearing

What frequency does an ILD work best for

high frequencies

Contrast sensitivty is reduced with aging, primarily for

high spatial frequencies

Blue (rate intensity function)

high spontaneous firing rate, sensitive to low intensities, saturate quickly compare to rods

S1

homunculus

horizontal pathway

horizontal and amacrine cells interact via lateral inhibition

utricular macula

horizontal plane Sensitive to horizontal linear acceleration and gravity

combinatorial neural code

how can we detect so many different scents if our genes only code for about 1000 olfactory receptors we can detect the pattern of activity across various receptor types intensity of odorant also changes which receptors will be activated specific time order of activation of OR receptors is important

Categorization

how me make sense of the world (how sensation is turned into meaning)

Dualism

idea that the mind has an existence separate from the material world of the body

Motion aftereffect (MAE)

illusion of motion of a stationary object that occurs after prolonged exposure to a moving object Existence of this effect implies an opponent-process system, like that of color vision

Body image

impression of our body in space it is possible to induce an out-of body experience

Does everyone see colors the same way

in general yes but as one ages the lens turns yellow However about 8% of the male population and 0.5% of the female population has some form of color vision deficiency aka color blindness

Umami

in most animals: triggered by many amino acids in humans: only monosodium glutamate (MSG) MSG is a neurotransmitter Pleasant "brothy" or "meaty" taste Added to some East-Asian foods Natural occurence: meat, fish, mushrooms, cheese, some vegetables, especially tomatoes Initial concerns about safety have been disproven

Pleasures of taste

in our evolutionary past, specific hungers for sugar and salt were adaptive Nowadays, these hungers lead many to unhealthy eating habits

Cultural relativism with respect to color perception

in sensation and perception, the idea that basic perceptual experiences may be determined in part by the cultural environment In general, some cultures have words (e.g. another word for varying shades of blue) for more specific colors and thus can easily identify the differences between specific colors more quickly

principle of good continuation

in spite of interruptions, one can still "hear" sound. The missing part is filled-in by the auditory system

Hair cell responses

in the absence of stimulation, hair cells release neurotransmitter at a constant rate When hair cell bundles bend, change in hair cell voltage is proportional to the amount of deflection

Critical period

in the study of development, a period of time when the organisms is particularly susceptible to developmental change

Prosopagnosia

inability to recognize faces

General agnosia

inability to recognize objects

Place agnosia

inability to recognize places

mirror agnosia

inability to understand mirrors

Focus of expansion (FOE)

indicates the heading direct i.e. the direction of subjective motion

Supertaster

individual who is a taster of PTC/PROP and has a high density of fungiform papillae

scene-based guidance

information in our understanding of scenes that helps us find specific objects in scenes

Herman Snellen

invented method for designating visual acuity in 1862

Limbic system

involved in many aspects of emotion and memory includes hippocampus, amygdala, anterior thalamic nucleus, septum, limbic cortex and fornix Olfaction is unique among the senses for its direct and intimate connection to the limbic system

How can hearing loss occur

it can be impaired by: obstructing the ear canal excessive buildup of ear wax in ear canal Conductive hearing loss ostosclerosis

why is refraction necessary?

it is necessary to focus light rays

What does shape provide in ambiguous apparent motion matches

it provides a slight bias to perceive horizontal motion, though it is easily overridden with attention

Additive color mixture

kind of mixing you get if you overlap spotlights in a dark room red, green, blue

Where system of touch

knowing where objects are in the environment when only using touch perception example: finding snooze button on alarm clock in the morning frame of reference: the coordinate system used to define locations in space Egocenter: the center of a reference frame used to represent locations relative to the body

Haptic perception

knowledge of the world that is derived from sensory receptors in skin, muscles, tendons, and joints, usually involving active exploration

Entry-level category/Basic

label that comes to mind most quickly when we identify the object (typically the basic level)

Low spatial frequency represents

large objects

Coding of amplitude and frequency in cochlea

larger amplitude = bigger shear of tectorial membrane

ganglion cells

last stage before information leaves through the eye and travels to and through the brain

The LGN processes right space on the

left side

20/200 (6/60)

legally blind

accomodation

lens can change its shape, and thus alter the refractive power

Accomodation

lens changes its focus

Where are global motion detectors in the brain

lesions in magnocellular layers of LGN impair perception of large, rapidly moving objects Middle temporal lobe (MT) plays an important role in motion perception. The vast majority of neurons in MT are selective for motion in a particular direction

visual pigments

light absorbing molecules created and used by photoreceptors

chromophore

light-catching part of pigment

Which wavelength diffracts more?

long

What can newborns detect?

looming motion

Cataracts

loss of transparency in lens (solved with silicone implants)

What frequency does an ITD work best for?

low frequencies

What type of frequency is diffracted?

low frequencies

Red (rate intensity function)

low spontaneous firing rate, sensitive to high intensities, selective over wide range, compare to cones

Inferotemporal (IT) cortex

lower portion of the temporal lobe, part of the "what" pathway

Harmonics

lowest frequency of harmonic spectrum (fundamental frequency) Auditory system is acutely sensitive to natural relationships between harmonics

What does each otolith organ contain

macula --> a specialized detector of linear acceleration and gravity

Ossicles

malleus, incus, stapes; smallest bones in body

Lateral geniculate nucleus has cells that are what

maximally stimulated by spots of light

A small disparity when talking about the horopter

means that the object is closer to the horopter

A big disparity when talking about the horopter

means that the object is further away from the horopter

How is efficiency measured

measured in terms of search slope, or ms/item tHe larger the search slope (more ms/item), the less efficient the search Some searches are efficient and have small slopes Some searches are inefficient and have small slopes Some searches are inefficient and have large slopes

tactile

mechanical displacement of skin

Otolith organs

mechanical structures in the vestibular system that sense both linear acceleration and gravity

retinal ganglion cells are still doing what

migrating and growing connections with the fovea

Contrast Threshold

minimum contrast (i.e., difference between light and dark bars) to detect pattern at specific spatial frequency (1000-990)/1000 = 0.01

two-point threshold

minimum distance necessary between two points of stimulation on the skin such that the points will be felt as two distinct stimuli

strabismus

misalignment of eyes such that single object in space is imaged on fovea of one eye and non-foveal area of the other (turned) eye

what does sensory integration typically lead to

more accurate information than can be obtained from individual senses alone

Superordinate-level category

more general term

When there is more fluid there is

more refraction

Otosclerosis

more serious type of conductive loss. Caused by abnormal growth of middle ear bones; can be remedied by surgery

motion-induced blindness

motion can make salient objects disappear

Linear motion

movements represented in terms of translation in the x-, y-, and z axes

Olfactory cleft

narrow space at back of nose into which air flows, where the main olfactory epithelium is located

myopia

nearsightedness: When the light entering the eye is focused in front of the retina and distant objects cannot be seen sharply; light converges in front of the retina

Phase locking

neuron fires only at distinct point in the period (cycle) of sound wave at given frequency

Moving from V1 to IT in the what pathway,

neurons respond to more and more complex stimuli

Is the tongue map true?

no

are geons always the best descriptions of objects?

no

emmetropia

no refractive error; normal vision

Geons are recognized by their what?

nonaccidental properties (helps solve problem of invariance)

Human olfactory apparatus

nose

inattentional blindness

not perceiving things that are in plain sight. Caused by absence of attention to the unseen object

Liking for saltiness is

not static early experiences can modify salt preference chloride-deficiency in childhood leads to increased preference for salty foods later Gestational experiences may affect liking for saltiness

Support

object does not appear to be resting on a surface

Gestalt law of common fate

objects moving in the same direction or moving in synchrony are perceived as a group or unit

Identification is difficult if geons are what?

obscured (vertices deleted)

What is optical flow used extensively in computer vision for?

obstacle detection and avoidance lane following automatic landing systems flight stabilization motion detection (e.g. alarm systems)

Parallax barrier

occluders positioned to selectively block pixels for one or the other eye

T junctions indicate

occlusion

orthonasal olfaction

olfaction through the nostrils

What is the retina of the nose?

olfactory epithelium

odors

olfactory sensations

common fate

onset and offset at the same time with a very short delay, e.g. in harmonics

Lenticular arrays

optics redirects light selectively into a particular eye

Neuroanatomical and evolutionary connections between odor and emotion

orbitofrontal cortex olfaction is processed here also the cortical area for assigning affective value (i.e., hedonic judgement) Helps explain increased emotionality of smells

Cognitive aspects of pain

pain: generally subjective experience, two components: sensation of painful source, emotion that accompanies it Areas S1 and S2 are responsible for sensory aspects of pain Researchers have recently identified areas of brain that correspond to more cognitive aspects of painful experiences

Attack (sound)

part of a sound during which amplitude increases

autonomic nervous system

part of the nervous system innervating glands, heart, digestive system, etc., and responsible for regulation of many involuntary acitons blood pressure is regulated by vestibulo-autonomic responses

triangle test

participant given three odors to smell, two of which are the same and one that is different participant must identify the odd odor the order of the three odors is varied and tested several times to increase accuracy difference between same and odd odors varied to determine discrimination threshold

Magnitude estimation

participants report how much (e.g. how many degrees) they think they tilted, rotated, or translated

Biological motion

pattern of movement of living things (i.e., humans, animals)

loudness

perceived intensity or magnitude

Phantom limb

perceived sensation from a physically amputated limb of the body parts of brain listening to missing limbs not fully aware of altered connections, attribute activity in these areas to stimulation from missing limb real pain might be felt if they perceive their phantom limbs to be in uncomfortable positions

proprioception

perception mediated by kinesthetic and vestibular receptors

pitch

perception of different frequencies

Timber aftereffect known as timbre contrast or timbre after effect

perception of timbre depends on context in which sound is heard

Gestalt perception assumes what?

perception relies on laws of physics, assumes viewpoints are not accidental

Are axes defined relative to person or gravity

person

Each macula is roughly what

planar and sensitive primarily to shear forces Hair cells are encased in a gelatinous structure that contains calcium carbonate crystals called otoconia

Basilar membrane

plate of fibers that forms the base of the cochlear partition and separates the middle and tympanic canals in the cochlea Any remaining pressure from intense sounds: transmitted from helicotrema back through tympanic canal, where absorbed by round window

inhibition

plays an important role in processing taste information in the brain functions to protect our whole mouth perception of taste when there are injuries to taste system. descending inhibition from taste cortex blocks pain perception has survival value: we need to eat even if we have a mouth injury

x axis (vestibular system)

points forward, direction the person is facing

y-axis (vestibular system)

points laterally, out of the person's left ear

corresponding retinal points

points on the retina of each eye where monocular retinal images of a single object appear are same distance from the fovea in each eye

z-axis

points vertically out of the top of the head

What do the red arrows in the aperture problem show?

possible velocity vectors that would all produce the same pattern of motion within the aperture

Do we learn to like or dislike smells separately for retronasal versus orthonasal olfaction?

possibly however, if an aversion is acquired retronasally, it usually shows up orthonasally as well

basal cells

precursor cells to olfactory sensory neurons

What are some features of the PPA

prefers scenes over faces or objects contains a neural representation of categories of natural scenes Category representation robust to the way the scenes are presented, e.g. line drawings vs. color photographs

insular cortex

primary cortical processing area for taste, first receives taste information

Selective

processing restricted to a subset of possible stimuli

supporting cells

provide metabolic and physical support for the olfactory sensory neurons

Receptors in tendons

provide signals about tension in muscles attached to tendons

scene context

provides an important cue for object detection

What does proximity provide in the ambiguous apparent motion matches

proximity provides a bias to perceive horizontal motion its also provides a bias to perceive vertical motion

How can the filtering property of the auditory system be measure

psychophysically This is achieved by measuring the ability of listeners to detect tones in the presence of bandpass noise

what are the two mechanisms for dark and light variation?

pupils regulates the amount of light entering the eye ganglion cells ignore variation in overall light level

Contrast sensitivity at birth is what?

quite poor but improves gradually with development

How do sound waves propagate in open air?

radially

critical bandwidth

range of frequencies that are conveyed within channel in auditory system

akinetopsia

rare neurophysiological disorder in which the affective individual has no perception of motion caused by disruptions to cortical area MT

Receptors in joints

react when joint is bent to an extreme angle

20/10 (6/3)

really good eye vision

Midget bipolar cells

receive input from a single cone

diffuse bipolar cell

receive input from multiple rods (up to fifty)

Faster reaction times for object-based attention when red dot is valid or near cued in the same area

red indicator flashes prior

What colors are complementary

red produces green (and vice versa) Yellow produces blue (and vice-versa)

Saccadic suppression

reduction of visual sensitivity that occurs when one makes a saccadic eye movement; eliminates smear from retinal image motion during an eye movement

Ipsilateral

referring to the same side of the body/brain

Most of the light we see is

reflected

Cone of confusion

regions of positions in space where all sounds produce the same time and level (intensity) differences (ITDs and ILDs)

What do the vestibular organs respond to?

respond to changes in velocity or acceleration

Stripe Detector

responds best to a line of light that has a particular width, surrounded on both sides by darkness

Anterior Cingulate cortex

responds differentially to hypnotic suggestions of pain

Midget bipolar cell off

responds to decreases in light

Midget bipolar cell on

responds to increases in light

What does stimulating taste receptor cells result in?

responses in taste nerves

4 kinds of pigment

rhodopsin (rods), long, medium, short (cones)

The LGN processes left space on the

right side

what are the three directions for the sense of rotation

roll, pitch, yaw

roll

rotation around x-axis

Pitch

rotation around y-axis

yaw

rotation around z-axis

interest when referring to saccades

scene based or knowledge based (bottom-up or top-down attention)

Adenosine triphosphate (ATP; a neurotransmitter)

secreted by cells without synapses

Olfactory epithelium

secretory mucosa functions to detect odorants in the inspired air

subtle differences between sensation and perception

sensation occurs when scent is neurally registered Perception occurs when becoming aware of scent sensations

two components of pain

sensation of painful source, emotion that accompanies it

olfaction

sense of smell

Adaptation

sense of smell is essentially a change detector examples: walking into a bakery and can only smell fresh bread for a few minutes. Someone who wears perfume every day cannot smell it might put a lot on

Gustation

sense of taste

linear motion

sensed when accelerating or decelerating in a car

Benefit of pain perception

sensing dangerous objects (hot pots in the kitchen) case of "Miss C" Born with insensitivity to pain Could not protect herself (did not sneeze or cough) Died at age 29 from untreated injection This is a huge problem for diabetic patients, who often lose sensation of their feet and become invalids because of untreated minor injuries

skin

sensory organ for touch largest sensory organ About 1.8 square meters (19 square feet) About 4 kg (9 pounds)

Mechanoreceptors

sensory receptors that are responsive to mechanical stimulation (pressure, vibration, movement) Head motion causes hair cell stereocilia to deflect, causing a change in hair cell voltage and altering neurotransmitter release

What does a prism do?

separates visible light into several colors

d prime

serves as a measure of signal separability (sensitivity of measurement). It tells us by how many standard deviations the two signals are separated. Defined as d' = Z(hit rate) - Z(false alarm rate) Z stands for the cumulative Gaussian distribution

Light from an object is composed of about how many wavelengths

several

spinothalamic pathway

several synapses in spinal cord slower information transmission provides mechanisms for pain inhibition

pheromones

signals for chemical communication between members of the same species that do not need to have any smell

What are VORs accomplished by

six oculomotor muscles that rotate the eyeball

Texture cue can give rise to an illusion in what?

size

Microvilli

slender projections on the tips of some taste buds that extend into the taste pore contain the sites that bind to taste substances not tiny hairs (as the name implies): we now know they are extensions of the cell membrane

C fibers

slower response sustained stimulation throbbing sensation that evolves after initial surge of pain

spinothalamic

slower, evolutionary older heat and pain, multiple synapses

Things really far will move what?

slowly

Two central categories about tastants

small charged particles that taste salty or sour (small ion channels in microvilli membranes allow some charged particles to enter but not others) Molecules perceived by G protein-coupled receptors (GPCRs) similar to those in the olfactory system. These molecules taste sweet or bitter

A high spatial frequency represents:

small objects

Filiform papillae

small structures on the tongue that provide most of the bumpy appearance. Have no taste function

ciliary muscle

smooth muscle portion of the ciliary body, which contracts to assist in near vision Assists in eye focus

Where are the neurons that are sensitive to tickling located

somatosensory cortex

How are touch sensations represented in the brain?

somatotopically analogous to retinotopy found in vision

All sounds can be described as

some combination of sine waves

relative size and relative height both provide what

some metrical information

stapes transmits vibrations of

sound waves to oval window, another membrane which represents border between middle and inner ear

Outer ear

sounds are first collected from environment by the pinnae sound waves are funnelled by the pinna into ear canal length and shape fo ear canal enhance sound frequencies main purpose of canal is to protect the tympanic membrane (eardrum)

What are some strategies to segregate sound sources

spatial separation, separation on basis of sounds' spectral or temporal qualities Auditory stream segregation: Perceptual organization of a complex acoustic signal into separate auditory events for which each stream is heard as a separate event

Retinal ganglion cells and LGN process

spots

What is the ability to perceive salt like?

static low sodium diets will increase intensity of salty foods over time

Evoked OAE

stimulated by pure tone frequency computed as difference between stimulation and sound measured at the ear used as a non-invasive hearing test

The reaction time depends on what

stimulus onset asynchrony between cue and stimulus

estropia

strabismus in which on eye deviates inward

boundary between the ambient air and the cornea does what?

strongest refraction

superior colliculus

structure in midbrain that plays important role in initiating and guiding eye movements when the superior colliculus is stimulated with electrical signals, eye movements can be observed

single unit recordings

study firing of individual neurons

Psychoacousticians

study how listeners perceive pitch

Multi unit recordings

study small ensembles of neurons

miss

subject did not respond when a signal was present

Polar angle

subset of visual field

Mixing of pigments is

subtractive color mixing

When a pattern of non-overlapping blue and yellow pigment is blurred the resultant mixture is additive (Gray) as opposed to what

subtractive green

Ménière's disease

sudden experience of dizziness, imbalance, and spatial disorientation can cause sudden falling down, can cause repeated vomiting from severe motion sickness caused by accumulation and sudden release of endolymph in the inner ear Often accompanies by tinnitus (ringing in the ear) Attacks are unpredictable Prognosis: often ends up in "burnt-out" stage, inner ear function lost, including hearing possible treatments: medications, implanted devices, or sometimes removal of the vestibular apparatus itself

ganglion cells can still report activity as they what?

sum up what going on at the photoreceptor level

lateral view of eye muscles

superior oblique superior rectus lateral rectus inferior rectus inferior oblique

what are the six muscles that are attached to each eye

superior oblique superior rectus lateral rectus inferior rectus inferior oblique medial rectus

Top view of eye muscles

superior rectus lateral rectus superior oblique medial rectus

levels of categorization

superordinate, basic, subordinate

Hair cells

support the stereocilia that transduce mechanical movement in the vestibular labyrinth into neural activity sent to the brain stem Hair cells act as the mechanoreceptors in each of the five vestibular organs

Binocular suppression

suppression of one of the two eye images

what taste preferences do infants show?

sweet evokes a "smilelike" expression followed by sucking sour produced pursing and protrusion of lips Bitter produced gaping, movements of spitting, and sometimes vomiting movements

What do type III cells have

synapses

Survival value of taste

system for detecting nutrients and antinutrients bitter: might signal poisons sour: configured to detect acidic solutions that might harm the body sweet and salty: our bodies need sodium and sugar to survive umami: seeking protein-rich food

four components of touch

tactile, temperature, pain, body sensations

The farther an object is rotated away from a learned view the longer it

takes to recognize

ATP can act on what

taste nerve fibers and adjacent cells

Orientation Tuning

tendency of neurons in striate cortex to respond optimally to certain orientations and less to others

What are the two muscles that comprise the middle ear

tensor tympani and stapedius purpose: to tense when sounds are very loud, muffling pressure changes Acoustic reflex takes ~200ms, So cannot protect against abrupt sounds (e.g. gun shot)

Vestibular information reaches the cortex via

thalamo-cortical pathways

ascending vestibular pathways pass from the vestibular nuclei to

thalamus on their way to the temporo-parieto-insular cortex

motion entrainment

the addition of flanker dots causes the center dot to appear in motion behind a square occluder

Perceptual phase space

the appearance of a display can have qualitatively different states depending on the iSI and displacement

Ensemble statistics

the average and distribution of properties, such as orientation or color, over a set of objects or a region in a scene

interposition

the background to pass through the object

chorda tympani

the branch of cranial nerve VII (the facial nerve) that carries taste information from the anterior, mobile tongue (the part of the tongue you can stick out)

Egocenter

the center of a reference frame used to represent locations relative to the body

Saturation

the chromatic strength of a hue

flavor

the combination of true taste (sweet, salty, sour, bitter, umami, and fat)

Flavor

the combination of true taste (sweet, salty, sour, bitter, umami, and fat) and retronasal olfaction

Binocular rivalry

the competition between the two eyes for control of visual perception, which is evident when completely different stimuli are presented to the two eyes

aromatherapy

the contention that odors can influence, improve, and alter mood, performance, and well-being, as well as the physiological correlates of emotion such as heart rate, blood pressure, and sleep No evidence for pharmacological effect of odors in humans effects explained by the emotional memory association with the scent odors can make you feel energized and have downstream effects on physiology and performance (E.g. peppermint smell can make you run faster, IF based on previously acquired association)

where does the eye focus images?

the cornea and the lens

LGN functions as a gateway to what?

the cortex

Relative disparity

the difference in absolute disparities of two elements in the visual scene (Relative depth of objects)

brightness

the distance from black in color space

aperture problem

the fact that when a moving object is viewed through an aperture (or a receptive field), the direction of motion of a local feature or part of the object may be ambiguous

What is an example of vection

the feeling of flying while watching an IMAX movie, being stopped in your car at a light next to a bus. The bus begins to roll forward and you press on the brake because you feel as if you are rolling backwards

perilymph

the fluid that fills ear canals

color opponent theory

the idea that color vision is based on a system of paired opposites of color

Specific hungers theory

the idea that deficiency of a given nutrient produces craving (a specific hunger) for that nutrient cravings for salty or for sweet are associated with deficiencies in those substances However, the theory has not been supported for other nutrients, such as vitamins Theory only holds for sweet and salty foods

tip-of-the-nose phenomenon

the inability to name an odorant, even though it is familiar one has no lexical access to the name of the odorant, such as first letter, rhyme, number of syllables, etc. One example of how language and olfactory perception are deeply disconnected Anthropologists have found that there are fewer words for experiences of smells compared to other sensations

agnosia

the inability to recognize familiar objects.

specific anosmia

the inability to smell one specific compound amid otherwise normal smell perception 50% of population has specific anomsia to androstenone found in armpit sweat and pork 50% perceive as "sweet musky-floral" and 50% perceive it as an unpleasant "urinous" podor sensitivity to androstenone can be trained (but why?) Shape-pattern theory can explain these findings

What happens to the endolymph when the head rotates

the inertia of the endolymph causes it to lag behind, leading to tiny deflections of the hair cells

subtractive color mixture

the kind of mixing you get if you illuminate colored filters with white light from behind cyan, magenta, and yellow

illuminant

the light that illuminates a surface

Odor hedonics

the liking dimension of odor perception, typically measured with scales pertaining to an odorant's perceived pleasantness, familiarity, and intensity

Direction (vestibular system)

the line along which one faces or moves, with reference to the point or region toward which one is facing or moving

amplitude

the magnitude of displacement of a sound pressure wave

Mitral cells

the main projective output neurons in olfactory bulbs

stapes has a smaller surface than

the malleus, so sound energy is concentrated

graded potential

the more photons, the less neurotransmitter

First order motion

the motion of an object that is defined by changes in luminance

Ensemble statistics are computed in what pathway?

the nonselective pathway

spatial frequency

the number of cycles of a grating per unit of visual angle (usually specified in degrees)

size

the object appears too large or too small relative to other objects in the scene

position

the object is likely to occur in that scene but is unlikely to be in that particular position

probability

the object is unlikely to appear in the scene

figure-ground

the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).

orbitofrontal cortex (OFC)

the part of the frontal lobe of the cortex that lies above the bone (orbit) containing the eyes receives projections from insular cortex involved in processing of temperature, touch, smell, and taste, suggesting it may be an integration area

categorical perception

the perception of speech sounds as belonging to discrete categories

Reverberation

the persistence of sound in a particular space after the original sound is produced due to reflections of the original sound

Mixing wavelengths does not change

the physical wavelengths

Rate Saturation

the point at which a nerve fiber is firing as rapidly as possible and further stimulation is incapable of increasing the firing rate Rate saturation means we cannot use a direct decoding rule

Sensory integration

the process of combining different sensory signals

Figure-ground assignment

the process of determining that some regions of an image belong to a foreground object (figure) and other regions are apart of the background (ground)

Cognitive Habituation

the psychological process by which, after long-term exposure to an odorant, one is no longer able to detect that odorant or has very diminished detection ability

retronasal olfactory sensation

the sensation of an odor that is perceived when chewing and swallowing force an odorant in the mouth up behind the palate into the nose such odor sensations are perceived as originating from the mouth, even though the actual contact of odorant and receptor occurs at the olfactory mucosa

vestibular organs

the set of five organs located in each inner ear that sense head motion and head orientation with respect to gravity three semicircular canals two otolith organs also called the vestibular labyrinth or vestibular system an often overlooked sense: evolutionarily very old

Displacement

the shift of the depicted pattern from frame 1 to frame 2

What is the tip of each stereocilium connected to and what is the thing that connects it called?

the side of its neighbor by a tiny filament called a tip link

amplitude (vestibular)

the size (increase or decrease) of a head movement (e.g. angular velocity, linear acceleration, tilt)

acuity

the smallest spatial detail that can be resolved

what does the cation trigger

the taste receptors via epithelium sodium channels (ENaC) All salts taste at least a little salty, but NaCl is the saltiest

Free fusion

the technique of converging or diverging the eyes in order to view a stereogram without a stereoscope

RSVP is used to study what

the temporal dynamics of visual attention

Color constancy

the tendency of a surface to appear the same color under a fairly wide range of illuminants must discount the illuminant and determine what the true color of a surface is regardless of how it appears

Similarity

the tendency to perceive things that look similar to each other as being part of the same group Group things together that are more similar

color space

the three-dimensional space, established because color perception is based on the outputs of three cone types, that describes the set of all colors

Anisometropia

the two eyes have different refractive errors (e.g. one is hyperopic and the other is not)

Areas of cortex that receive projections from the vestibular system also project where

the vestibular nuclei

Labeled lines coding

theory of taste coding in which each taste fiber carries a particular taste quality (major source of controversy in literature) Other possibilities: patterns of activity across taste neurons temporal coding of taste neurons Examples of types of coding in other senses: color vision and olfaction use patter coding Hearing uses labeled-line approach olfaction uses temporal coding

Pre-attentive features are free floating until what?

they are bound together by spatial attention

How do cones respond?

they are fast, wide range, but only after a minimum of light (10 photons per second)

How do rods respond?

they are sensitive but slow and can respond to one photon

Reissner's membrane

thin sheath of tissue separating the vestibular and middle canals in the cochlea

Knowledge and expectations can influence perception of what

tilt and motion

otoconia

tiny calcium carbonate stones in the ear that provide inertial mass for the otolith organs, enabling them to sense gravity and linear acceleration

what is the goal of color perception

to perceive changes in illumination (color of light) To perceive changes in reflectance (color of object)

Grouping by timbre

tones that have increasing and decreasing frequencies, or tones that deviate from rising/falling pattern "pop out" of sequence

what is a possible solution to lesions?

transcranial magnetic stimulation coil introduces strong magnetic field that is sent to a specific region

Interocular transfer

transfer of an effect (e.g. adaptation) from one eye to the other

light waves

transverse oscillations in electric and magnetic fields

Pain

triggered by nociceptors responses to noxious stimuli can be moderated by anticipation, religious belief, prior experience, watching others respond, excitement

What are some characteristics of reichardt motion detectors?

tuned to particular speeds If a moving object is too slow or too fast, then signals will arrive at the comparators at different times= no signal Tuned to specific directions of motion if an object moves in the wrong direction, then signals will arrive at the comparators at different times = no signal Simple operation, but can lead to problems: may respond to stationary patterns or flicker

place code

tuning of different parts of cochlea to different frequencies (mostly due to shape of basilar membrane)

What is salt made up of

two charged particles cation Na+ Anion Cl-

HSB space

two cones, connected at their base, with white at the top tip and black at the bottom tip

good continuation

two elements will tend to group together if they lie on the same contour

How many stages are involved in stereopsis

two stages

What type of picture is recognized easily but poorly haptically

two-dimensional pictures

Two otolith organs in each ear

utricle and saccule

Health consequences of taste sensation

variations in sensory properties of foods and beverages affects food preferences and diet some vegetables are too bitter for supertasters among men getitng routine colonoscopies, those tasting PROP as the most bitter had the most colon polyps Fats also taste bitter to supertasters, if they avoid it could lower their risk for heart disease

Visual-vestibular integration

vection: an illusory sense of self motion produced when you are not, in fact, moving

saccular macula

vertical plane Sensitive to vertical linear acceleration and gravity

What comprises the three-neuron arc

vestibular afferent neurons (blue) Connecting neurons (green) Efferent oculomotor neurons (red)

RBC predicts what

viewpoint invariance

What are geometric properties of objects most important for?

visual recognition

If adaptation to a stimulus occurs, then it must be that a group of neurons was what?

was coding that stimulus and got fatigued

sine wave (Sound)

waveform for which variation as a function of time is a sine function

diffracted

waves can be bent around obstacles.

To calculate or perceive motion what do we not require?

we do not require discrete objects just as we do not require objects to perceive depth (RDS)

In the electromagnetic spectrum

we perceive light of a wavelength of 700nm as red

Familiarity and intensity

we tend to like odors we've smelled many times before Intensity has a more complicated relationship with odor liking Inverted U shape function Linearly decreasing function

threshold estimation

what is the minimum motion needed to correctly perceive motion direction?

optokinetic nystagmus (OKN)

when following a moving object, the eyes return to the object's original position when the object disappears from the field of view

rotation vection

when observers are looking at a rotating display they report a sense of tilt but of not feel as if they have been turned upside down

Torsional eye movements

when the head is rolled about the x-axis, the eyeballs can be rotated a few degrees in oppsite direction to compensate

Absolute threshold for touch

wing of fly on cheek dropped from 3 inches

Olfactory detection thresholds

women generally have lower thresholds than men especially during ovulatory period of menstrual cycles, but sensitivity not heightened during pregnancy Professional perfumers and wine tasters can distinguish up to 100,000 odors By 85, 50% of population is effectively anosmic

When both M and L cones are activated what color do you perceive?

yellow

Is olfaction mostly synthesis

yes and analytical abilities can be trained

Retina

A light sensitive membrane in the back of the eye that contains rods and cones, which receive an image from the lens and send it to the brain through the optic nerve Decreases amount of light by 50%

Absolute threshold for smell

One drop of perfume diffused throughout a three-room apartment

Synapse

The junction between neurons that permits information transfer

functional magnetic resonance imaging (fMRI)

an imaging technique used to examine changes in the activity of the working human brain by measuring changes in the blood's oxygen levels

neurophysiology

brain areas involved in perception

Absolute threshold for vision

candle flame 30 miles away

just noticeable difference

the minimal change in a stimulus that can just barely be detected

accommodation

the process by which the eye's lens changes shape and thus alters the refractive power

Psychophysics

the science of defining quantitative relationships between physical and psychological (subjective) events (What can we measure and how can we measure it?)

Psychophysics

the science of defining quantitative relationships between physical and psychological events

electrophysiology

the study of the electrical activity of cells

What are the five things one can do with light?

1. Absorbed 2. Diffracted 3. Reflected 4. Transmitted 5. Refracted

What is the order for perception of something?

1. Capturing physical energy 2. Physical Stimulation 3. Transduction into neural signal: sensation 4. Transmission of neural signal to the brain 5. Cortical processing: Perception 6. Active feedback

Signal detection theory

A psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of noise

Astigmatism

A visual defect caused by the unequal curving of one or more of the refractive surfaces of the eye, usually the cornea

transverse waves

A wave in which the particles of the medium move perpendicularly to the direction the wave is traveling

light

A wave; a stream of photons, tiny particles that each consist of one quantum of energy

Electroencephalogram (EEG)

An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

Weber's Law

As stimulus level increases or decreases, the magnitude of change must increase proportionately to remain noticeable

Hermann von Helmholtz

First person to measure the speed of neural impulses, invented the ophthalmoscope, Wrote on the sensation of tone, one of the first studies of auditory perception

Santiago Ramon y Cajal

Hispanic doctor awarded the Nobel Prize in 1906 for his work on the structure of the nervous system

James J. Gibson

Instead of viewing perception as passive, he postulated an active "information pick-up" of perceptual units from environment. Gibson coined the term "affordance" to describe the opportunities for action provided by a particular object or environment - very influential in design and ergonomics

Rods

Photoreceptors that are specialized for night vision

Materialism

The idea that only thing that exists is matter, and that all things, including mind and consciousness, are the results of interactions between bits of matter

Panpsychism

The idea that the mind exists as a property of all matter--that is, that all matter has consciousness

Tapetum

The iridescent portion of the choroid tissue that is located behind the retina. Found in animals that have good night vision, it reflects light back through the retina.

Crystalline lens

The lens inside the eye, which enables changing focus.

Perception

The processing and interpretation of neural energy from sensations

Plato and "The Allegory of the Cave"

Used by Plato to describe moving across the Divided Line (realm of becoming to the realm of being) and the Simile of the Sun. People are chained like prisoners forced to stare at the wall of a cave. What they perceive to be real are actually artificial reflections cast by fire and puppets. The philosopher is the prisoner who broke free to ascend outside the cave into the sunlight.

6 senses

Vision Audition Smell (olfaction) Taste (gustation) Touch Balance

Positron Emission Tomography (PET)

a method of brain imaging that assesses metabolic activity by using a radioactive substance injected into the bloodstream

Magnetoencephalography (MEG)

technique that measures brain activity by detecting tiny magnetic fields generated by the brain

When we want to identify perceptual processes, we can measure

the behavioral response of organisms to stimulation and the specific neural energies in response to stimulation

sensitivity

the ease with which an observer can tell the difference between two stimuli (or the presence and absence of a stimulus)

correct rejection

the subject did not respond when no signal was present

false alarm

the subject perceived a signal when none was present

hit

the subject responded affirmative when a signal was present

Absolute threshold for hearing

the tick of a watch 20 feet away in a quiet room