Sensation and Perception- TEST ONE

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Info in LGN is best described as ____________________________.

BI-DIRECTIONAL, WITH SIGNALS COMING FROM RETINA AND CORTEX TO THE LGN.

Rods and cones synapse with _____ cells, which then synapse with _______ cells.

BIPOLAR; GANGLION

A participant is viewing black & white (full contrast) grating stimulus with a cycle subtending two arcminutes of visual angle. If the photoreceptors in line with this grating have receptive fields of slightly under 1 arcminute (e.g. centers of the receptors are just under 1 arcminute apart) the stimulus will likely be perceived as ________________; If the photoreceptors have receptive fields of 1.5 arcminutes, the stimulus will likely be perceived as ___________.

BLACK AND WHITE BARS; A SOLID GRAY PATCH

Vera adapts to a yellow stimulus for about 60 seconds. If she looks at a white surface and blinks, the after image she sees will appear to be ______.

BLUE

Color may play role in determining _____.

FORM; form and color linked physiologically by neurons with side-by-side receptive fields

Dr. Lanzilotti wants to create a stimulus that will produce an afterimage of a red heart shape against a white background. He should make the heart _____ and the background _____.

GREEN; BLACK

Blue & yellow painted mixed yields ______; blue & yellow lights mixed yields _______.

GREEN; WHITE

If you cover the penumbra with a black marker, the perception of the border ______________.

CHANGES FROM AN ILLUMINATION EDGE TO A REFLECTANCE EDGE.

The double the perceived brightness of a light you need to multiply the physical intensity of the light by about 9. This is an example of response _____.

COMPRESSION

The difference between the METHOD OF LIMITS and the METHOD OF ADJUSTMENT is that in the method of adjustment, stimulus intensity is changed at a ______ manner

CONTINUOUS

The structure of the eye that provides about 80% of eye focusing power is the _____.

CORNEA

When visual pigments become bleached they are _______________.

DETACHED FROM THE OPSIN.

In Ungerleider & Mishkins (1982) research monkeys who had had their temporal lobes removed had difficulty _______________.

DISCRIMINATING BETWEEN OBJECTS.

RESPONSE BIAS

Differences in response criteria exist among participants

Finding the neural correlates of consciousness is related to the ________________.

EASY PROBLEM OF CONSCIOUSNESS

EXTRASTRIATE BODY AREA

EBA; body parts

PRESBYOPIA

"old eye" ; distance of near point increases, due to hardening of lens and weakening of ciliary muscles

WAVELENGTH SENSITIVITY CONES

(S) BLUE; (M) GREEN; (L) RED

MAGNITUDE ESTIMATION

(scaling) stimuli are above threshold, observer given a standard stimulus and a value for its intensity; observer compares standard stimulus to test stimuli by assigning numbers relative to the standard; response compression and expansion

PROCES NEEDED FOR TRANSDUCTION

1) retinal molecule changes shape 2) opsin molecule separates 3) retina shows pigment bleaching 4) retinal and opsin must recombine to respond to light 5) cone pigment regenerates in 6 mins 6) rod pigment takes over 30 mins to regenerate

Considering Weber's work with JNDs, if a person was just able to notice the difference in weight b/t a 500 g weight & a weight 10g higher, we could reasonably expect the lowest difference this could detect between a 1000g weight & another weight would involve a weight ____ g heavier.

20

Demetri is a participant in an auditory detection study using the METHOD OF CONSTANT STIMULI. He never detects the 10 unit tone. He detects the 20 unit tone 25% of trials, detects the 30 unit tone 50%, 40 unit tone 80%, and 50 unit tone 95%. His threshold for hearing tones would be taken as the _______.

30 unit tone

An electrode is placed in an orientation column that responds best to orientations of 45 degrees. The adjacent column of cells will probably best respond to orientations of ____ degrees.

40

Visible light is between __________ nm within the electromagnetic spectrum.

400 and 700

Visual spectrum range ____ nm to _____nm

400 nm (blue) to 700 nm (red)

CONES

5 million; daylight, mostly in fovea (small area of extremely sharp vision), high acuity, low sensitivity; one on one convergence, need more light to respond than rods; 6 peripheral cones to one ganglion;

ROD

90 million; night vision; only in periphery; low acuity, high sensitivity, achromatic (no color); greater convergence (many rods into ganglion cells, increases response, no detail) 120 rods to one ganglion

LGN received _____ of input coming from optic nerve.

90%

RESPONSE CRITERION

A persons individual response bias

After training participants of the recognition of Greeble stimuli, Gauthier et. al. found that the neuron in the FFA responded _________________.

ABOUT AS WELL TO GREEBLES AS HUMAN FACES.

When shown a picture of a sparrow, Kathy most quickly says "bird," slightly later coming up with "sparrow." For Kathy "bird" serves as _______.

ENTRY LEVEL CATEGORY

Response __________ occurs in a magnitude estimation experiment often doubling the stimulus intensity ______ than doubles the subjective magnitude of the stimulus.

EXPANSION; MORE

Distance when light becomes focused is called the _______ past which focus is impossible without artificial correction.

FAR POINT

FUSIFORM FACE AREA

FFA; faces

SENSATION

Ability to detect a stimulus and perhaps to turn that detection into a private experience

Opsin separates from retinal, must recombine before cell can _______

FIRE TO LIGHT AGAIN

RESOLUTION ACUITY

finest high contrast detail we can visually resolve; chiefly determined by spacing of retinal photoreceptors; visual system samples grating stimulus through discrete receptors

VISUAL CORTEX NEURONS

fire to specific features of a stimulus; pathway away from retina shows neurons that fire to more complex stimuli

METHOD OF CONSTANT STIMULI

five to nine different intensities are presented in random order, multiple trials presented. threshold is the intensity that results in detection in 50% of the trials

MACULAR DEGENERATION

fovea and small surrounding area are destroyed; creates "blind spot" on retina; most common in older individuals

PENUMBRA

fuzzy outline at the edge of a shadow; signals an illumination edge

ON CENTER CELLS

ganglion cell preference; increase firing rate when middle of receptive field stimulated and decreased firing rate when outer area of receptive field stimulated

RETINITIS PIGMENTOSA

genetic disease; rods are destroyed first; foveal cones can also be attacked, several cases result in complete blindness

If entire cycle covered by single cone's receptive field, pattern is lost and we perceive ____

gray field

Receptive field must be smaller than _____ the period of the sine wave to perceive texture.

half

COLOR VISION BENEFITS

helps us classify and identify objects; facilitate perceptual organization of elements into objects; evolutionary advantage in foraging for food

OPPONENT-PROCESS THEORY

hering; color vision is caused by opposing responses generated by blue and yellow, and green and red; if you cant see red then you cant see green, cant see yellow then cant see blue; pairs respond in opposing fashion -> chemical reactions in retina; explains neural response for cells connected to the cones further in the brain -later perceptual system

HARD PROBLEM OF CONSCIOUSNESS

how do physical responses cause experience?

SURROUNDEDNESS

if one region is entirely surrounded by another, it is likely that the surrounded region is the figure

ASTIGMATISM

if shape of cornea is not symmetrical light will not focus correctly; vertical and horizontal light rays may focus different points before/behind retina

Amount of light reaching eye depends on:

illumination and object's reflectance

OCCULAR DOMINANCE COLUMNS

in LGN cells respond to only one eye or the other; in V1 preferential activation for one eye

LATERAL GENICULATE NUCLEUS (LGN)

in thalamus; major function is to regulate neural info from the retina to visual cortex

ACHROMATIC

lacking color (white, gray, black)

PHOTOPIC (DAY) VISION

light is bright enough to stimulate cone receptors and bright enough to saturate rod

SCOTOPIC (NIGHT VISION)

light is bright enough to stimulate rod receptors but not enough to stimulate cone receptors (night vision)

HYPERCOLUMN

location column with a full range of orientation columns

CEREBRAL ACHROMATOPSIA

loss of ability to see color due to damage to the brain; other damage cause including prosopagnosia (inability to recognize faces) --> color perception results from activity in many different visual areas

ACUITY

measure of the smallest spatial detail that can be accurately perceived

METHOD OF ADJUSTMENT

method of limits in which subject controls the change in the stimulus (like adjusting the stereo volume); repeated trials averaged for threshold

JUST NOTICEABLE DIFFERENCE

minimal difference between two stimuli that can be correctly distinguished from each other; discrimination between two stimuli

PROTANOPIA

missing long wavelength pigment; sees short wavelengths as blue; as wavelengths increases, blue becomes less saturated until hitting neutral point (perceived as gray); above neutral point, they see yellow which becomes less intense at longer wavelengths

DEUTERANOPIA

missing the medium wavelength pigment; perceptually very similar to protanopia; individuals see short wavelengths as blue; above neutral point they see yellow

TRITANOPIA

missing the short wavelength pigment; not linked to x-chromosome; individuals see short wavelengths as blue, above neutral point they see red

ADDITIVE COLOR MIXTURE

mixing lights of different wavelengths; all wavelengths are available for the observer to see; ADDING new wavelengths to the existing light (blue light + yellow light = white light)

SUBTRACTIVE COLOR MIXTURE

mixing paints with different pigments; additional pigments reflect fewer wavelengths; each component paint still absorbs the same wavelengths as before, so the only wavelengths reflected from the combination are those reflected by BOTH paints (blue paint + yellow paint = green paint)

EFFERENT NEURONS

motor neurons; generate responses in muscles and glands

MYOPIA

nearsightedness; eye too long, cannot focus on far objects

ANOMALOUS TRICHOMAT

needs three wavelengths, like in normal vision, but mixes them in different proportions than normal trichromats; impaired ability to discriminate between wavelengths that are close together

EASY PROBLEM OF CONSCIOUSNESS

neural correlate of consciousness (NCC) how physiological responses correlate with experience

ORIENTATION COLUMNS

neurons within columns fire maximally to the same orientation of stimuli; adjacent columns change preference in orderly fashion (within location columns)

PERCEPTION OF LIGHTNESS

not related to the amount of light reflected by an object (which is dynamic); is related to the percentage of light reflected by an object (which is static)

VISUAL SEARCH

observers look for one stimulus in a set of many stimuli

PRINCIPLE OF UNIVARIANCE

once a photon of light is absorbed by a visual pigment molecule, the identity of the light's wavelength is lost; we only have the AMOUNT absorbed to go on

SPARSE CODING

only a relatively small number of neurons are necessary for an object in distributed coding; can be viewed as midpoint between specificity and distributed coding

DISTRIBUTED CODING

pattern of firing across many neurons codes specific objects; large number of stimuli can be coded by a few neurons

BRIGHTNESS

perceived intensity of the color (light blue vs dark blue)

COLOR CONSTANCY

perception of colors as relatively constant in spite of changing light sources

MONOCHROMAT

person with only one receptor mechanism; world in grayscale; needs only one wavelength to match any color in the spectrum; rare typically hereditary; usually only rods, no functioning cones; low acuity vision

DICHROMAT

person with two receptor mechanisms; needs two wavelengths to match any other color

BLIND SPOT/OPTIC DISC

place where optic nerve leaves eye (no receptors here); located on edge of visual field

GOOD CONTINUATION

points that when connected result in straight or smooth curves belong together/objects partially covered by other objects are seen as continuing behind the covering object

VENTRAL STREAM

processes what info; PPA, FFA, EBA

DORSAL STREAM

processes where (and how) information; fast but colorblind; location and action

CHROMATIC ADAPTATION

prolonged exposure to chromatic color leads to receptors: adapting when stimulus color selectively bleaches a specific cone pigment, decreasing in sensitivity to color; occurs to light sources leading to color constancy

GLOBAL SUPERIORITY EFFECT

properties of a whole/larger object take precedence over smaller parts on the object

TYPES OF DICHROMATISM

protanopia, deuteranopia, tritanopia

METHOD OF LIMITS

psychophysical method in which the particular dimension of a stimulus, or the difference between two stimuli, is varied incrementally until the participant responds differently (HEARING TEST); crossover point is threshold

LOCATION COLUMNS

receptive fields at same location on the retina are within a column

VIEWPOINT INVARIANCE

recognizing objects regardless of viewing angle

REFLECTION

redirect something that strikes a surface- esp light, sound or heat- usually back toward point of origin; mirror

OCCLUSION RELATEABLE SHAPES

relatability is the degree to which two line segments appear to be a part of the same contour; smooth convex or concave curve -> relatable; s curve required -> unrelatable

UNGERLEIDER & MISHKIN EXPERIMENT

removing part of parietal lobe in monkey resulted in problems with landmarks discrimination (where pathway); removing part of temporal lobe in monkey resulted in problems with the object discrimination task (what pathway)

COMPLEX CORTICAL CELL CHARACTERISTICS

responds best to movement of a correctly oriented bar across the receptive field. many cells respond best to a particular direction of movement

END-STOPPED CORTICAL CELL CHARACTERISTICS

responds to corners, angles, or bars of a particular length moving in a particular direction

ACCOMODATION

results when ciliary muscles are tightened which causes lens to thicken

ISOMERIZATION

retinal changes its shape; triggers enzyme cascade (enzymes facilitate chemical reactions, cascades means that a single reaction leads to increasing numbers of chemical reactions = how isomerizing one pigment leads to the activation of a rod receptor)

ROD DARK ADAPTATION BEHAVIOR

rods overwhelmed with moderately bright light; keyed to low light vision, can detect a single photon on light; recover sensitivity after being overwhelmed slowly

AMACRINE CELLS

run laterally among bipolar and ganglion cells; implicated in contrast enhancement and detection of changes in light pattern over time, but precise function is still unknown

AFFERENT NERVES

sensory neurons; transduce signals (e.g. vision, hearing, and touch)

LGN PATHWAYS/FEEDBACK

signals are received from retina, the cortex and brain stem and thalamus; signals are organized by eye, receptor type, and type of environmental info

SIMILARITY

similar things are grouped together

ACCIDENTAL VIEWPOINT

single, precise viewing position that leads to an erroneous regularity grouping of the visual image that is not present in reality

Spatial frequency:

specific cells have receptive fields that tune them to see spots of a certain size

SPECIFICITY CODING

specific neurons responding to specific stimuli; leads to "grandmother cell" hypothesis; recent research shows cells in hippocampus that respond to concepts like halle berry; problems: too many different stimulus to assign specific neurons; most neurons respond to a number of different stimuli

MIDDLE VISION

step that comes after low-level processes (line, shape, color, angle) but before object recognition (high level); finding edges, texture, segmentation and grouping, figure and ground, occlusion, parts and wholes; decipher blurry faces

DOUBLE OPPONENT NEURONS

suggested as important in perception of boundaries between two different colors

SINGLE OPPONENT NEURONS

suggested as important in perception of color within regions

MEMORY COLOR

the effect on perception of prior knowledge of the typical colors of objects; the colors of very familiar objects are judged as richer and more saturated than are the colors of unfamiliar objects reflecting the same wavelengths

If dark & light bars of given cycle land on separate cones we see ____

the pattern

SIZE

the smaller region is more likely to be figure; car smaller than road, plane smaller than sky

METAMERS

the stimuli in metamerism (single wavelength light vs combination of 3 different wavelengths of light); look alike because they both elicit same response pattern in the 3 cone receptors (green- large response in M receptor, red- large response in L receptor)

When using the METHOD OF CONSTANT STIMULI the ABSOLUTE THRESHOLD is determined by calculating

the stimulus intensity detected 50% of the time

COMMON FATE

things moving in same direction are grouped together

PROXIMITY/NEARNESS

things that are near to each other are grouped together

REACTION TIME

time from presentation of stimulus to observer's response is measured (measures visual search)

REFRACTION

to alter the course of a wave of energy that passes into something from another medium, as water does to light entering it from the air (lens/eye); faster medium to slower medium like air to water, from slower medium to faster medium like water to air_

INTER NEURONS

transmit and process signals: inhibit or facilitate other nerves to fire

SELECTIVE TRANSMISSION

transparent objects, such as liquids, selectively allow wavelengths to pass through

UNILATERAL DICHROMAT

trichromatic vision in one eye and dichromatic in other

RATIO PRINCIPLE

two areas that reflect different amounts of light look the same if the ratios of their intensities are the same

SIGNAL DETECTION THEORY

used to take individuals response criteria into account

VENTRAL PATHWAY

what

SELECTIVE REFLECTION

when some wavelengths are reflected more than others (chromatic colors or hues occur when this happens: blue, green, red)

METAMERISM

when two physically different stimuli are perceived identically

OPTIC CHIASM

where inner visual fields cross other hemispheres

DORSAL PATHWAY

where/how

EDGE ENHANCEMENT

white figure tends to appear brighter than background

TRICHROMATIC THEORY OF COLOR VISION

young and helmholtz; three different receptor mechanisms are responsible for color vision; based on color matching procedure; light of a given wavelength stimulate a given receptor mechanism to varying degrees; explains the responses of the cones in the retina -early visual system

Cerebral achromatopsia is when a person ______________________.

HAS NORMAL CONE FUNCTIONING, BUT CANNOT EXPERIENCE COLOR DUE TO A BRAIN INJURY.

A unilateral dichromat ____________________.

HAS TRICHROMATIC VISION IN ONE EYE AND DICHROMATIC VISION IN THE OTHER EYE.

If a kitten is raised in an environment of just horizontal lines, the kitten would _____________________.

HAVE CORTICAL CELLS THAT RESPOND TO HORIZONTAL LINES, BUT FEW/NONE TO VERTICAL LINES

The edge between a dark shadow and an illuminated checkerboard is an _________

ILLUMINATION EDGE.

The PRINCIPLE OF SIMILARITY can account for grouping of stimuli that are similar _____________.

IN ORIENTATION, SHAPE, AND SIZE.

Prosopagnosia is an ________________.

INABILITY TO RECOGNIZE FAMILIAR FACES.

Convergence (e.g. the input of multiple rods ultimately impacting a single ganglion cell) results in _________ sensitivity and _______ acuity.

INCREASED; DECREASED

Two receptor types let us distinguish wavelengths _____________.

INDEPENDENT OF LIGHT INTENSITY.

INFEROTEMPORAL CORTEX

IT CORTEX; IT cells respond specifically to certain items; for example firing vigorously to the sight of a face

Weber's Fraction

JND change relative to physical intensity stimulus: if you notice difference between 40g and 41g you can tell difference between 400g and 410g

Peripheral cones ___ densely packed than foveal cones.

LESS

Types of striate cortex

LOCATION, ORIENTATION, OCCULAR DOMINANCE

A ____ focal length provides a narrow field of view

LONG

The first step in the procedure for __________ is to present to the participant a standard stimulus & assign a numerical value to that stimulus.

MAGNITUDE ESTIMATION

Color constancy works best when an object is surrounded by ______ colors.

MANY

Participants perceive a 620 nm pattern as being redder if that pattern has the shape of a stop sign rather than a mushroom shape demonstrates ________.

MEMORY COLOR

ABSOLUTE THRESHOLD

MINIMAL amount of stimulation necessary for a person to detect the stimuli 50% of the time; discrimination between stimulus presence or absence

A neuron with an excitatory center, inhibitory surround receptive field will respond most when we stimulate ________.

ONLY THE CENTER

Differences in the structure of _____ are responsible for the different absorption spectra.

OPSIN

Two main components to pigment molecules

OPSIN (large protein) and RETINAL (light sensitive molecule)

The _______ carries information from the retina toward the brain.

OPTIC NERVE

SIGNAL PATHWAYS FROM RETINA TO BRAIN

Optic nerve -> Optic chiasm -> LGN -> 2 pathways to temporal lobe (ventral & parietal) -> Frontal lobe

Color perception depends on the _________ in three receptor mechanisms.

PATTERN OF ACTIVITY

Light when traveling can be described in terms of wavelength or particularly when absorbed as, as consisting of small packets of energy called _______.

PHOTONS

Rods and cones (_____) -> _______ -> _______ -> ______

PHOTORECEPTORS; HORIZONTAL CELLS; BIPOLAR CELLS; GANGLION CELLS

The EBA is activated by __________.

PICTURES OF BODY PARTS.

PARAHIPPOCAMPAL PLACE AREA

PPA; scenery, locations

The Olympic symbol is an example of the Gestalt principle of ______________.

PRAGNANZ/GOOD FIGURE/SIMPLICITY

Light enters the eye through the ____ and is focused by the ____ and ____ to a sharp image on the _____.

PUPIL; CORNEA; LENS; RETINA

Lorelei's mother is 60. B/c of the condition called _____, the closest distance at which she can focus an object is probably about _________.

Presbyopia; 100 cm.

The major dependent variable used in the VISUAL SEARCH METHOD is _______.

REACTION TIME

Basic colors in color circle are: ________.

RED, GREEN, BLUE, YELLOW

The reflectance curve for a white piece of paper would _________________.

REFLECT LONG, MEDIUM, & SHORT WAVELENGTHS EQUALLY.

If you look at a folded index card through a pin hole, you see the border formed by the crease as a ___________ because the card looks ______.

REFLECTANCE EDGE; FLAT

Colors of objects are determined by the wavelengths of _____ light

REFLECTED

Visual transduction (convergence of light energy to chemical and ultimately electrical signals for processing) occurs when the ______ absorbs one photon of light.

RETINAL

_________ reacts to light to start the process of transduction.

RETINAL

The ____________ can be described as the electronic map of the retina on the cortex.

RETINOTOPIC MAP

_____ AND ____ are the visual receptors in the _____ that contain visual pigment.

RODS; CONES; RETINA

Activity in the PPA is the ____________________.

SAME FOR PICTURES OF FURNISHED AND EMPTY ROOMS

A _____ focal length provides a wide field of view.

SHORT

The theory that accounts for response criterion in a detection experiment is __________.

SIGNAL DETECTION THEORY

Least likely represented system to be in place in human visual system: ________

SPECIFICITY CODING

NOTE ABOUT WAVELENGTH SENSITIVITY

Since rods are insensitive to higher wavelengths (red), we can use red light for additional illumination at night without affecting our night vision (we stay dark adapted)

The difficulty of reading under dim light conditions can be explained by ___________________.

THE FACT THAT ROD FUNCTIONING PREDOMINATES DURING DARK ADAPTATION, THEREFORE POOR ACUITY.

The cortical magnification factor occurs in humans because _______________.

THE SMALL AREA OF THE FOVEA ACCOUNTS FOR A LARGE AREA OF THE CORTEX

When looking at a scene, the different sections of the scene are processed by many different location columns. Through the use of a ll the location columns the entire scene can be perceived. This effect is referred to ______.

TILING

TRANSDUCTION

The process of transforming energy in the environment into electrical energy in the neurons

The ability to readily recognize differently angled views of an object as the same object is an example of ____________.

VIEWPOINT INVARIANCE

We conceptualize light as a ________ when it travels and a _____ stream of photons when absorbed.

WAVE; PARTICLE

The blind spot, or optic disc, is located ___________.

WHERE THE OPTIC NERVE LEAVES THE EYE

A non-accidental T-junction typically indicates that________________.

YOU ARE SEEING MORE THAN ONE OBJECT IN THAT AREA, WITH ONE IN FRONT OF THE OTHER.

SYMMETRY

a symmetrical region is more likely to be figure

CORTICAL MAGNIFICATION

acuity drops off as the image moves away from the fovea; entire visual system from receptors to cortex emphasize central vision; a small area of the fovea is represented by a large area on the visual cortex

SATURATION

adding white to a color makes it less saturated; strength of the hue (white, pink, red)

LENS

adjusts shape for object distance; 20% of vision

DOUBLE DISSOCIATION

after brain damage some individuals have difficulty recognizing faces but can recognize objects or vice versa

Y AND ARROW JUNCTIONS

almost always indicate object corners (no occlusion)

T-JUNCTION

almost always occur wen one object is occluding another

CATARACT

alterations to crystal in lens creates regions of increased capacity; interferes with vision through increased absorption and scattering of light

GRATING STIMULI

alternating dark and light bars; measured by acuity

SELECTIVE REARING

animals reared in environments that contain only certain types of stimuli; neurons that respond to these stimuli will become more dominant due to neural plasticity; Ex: rearing kittens in tubes with either horizontal or vertical lines; both behavioral and neural responses shared the development of neurons for the environmental stimuli

RECEPTIVE FIELD

area of the retina at which stimulation alters the firing pattern of the ganglion cell (increase or decrease)

REPONSE EXPANSION

as intensity INCREASES the perceived magnitude INCREASES MORE QUICKLY than the intensity (I.E. SHOCK)

RESPONSE COMPRESSION

as intensity INCREASES, the perceived magnitude increases more SLOWLY than the intensity (I.E. BRIGHTNESS)

SINE WAVES

building blocks for understanding visual and auditory perception; defined by amplitude and frequency; shape is "sinusoidal" with rounded peaks unlike other types of waves like those we see breaking on a beach

OPTIC NERVE FIBER (GANGLION CELL) CHARACTERISTICS

center-surround receptive field, responds best to small spots, but will also respond to other stimuli

LGN CHARACTERISTICS

center-surround receptive fields very similar to receptive field of a ganglion cell

Object recognition

changes in rotation, distance, lighting, occluded view

INTENSITY

changes perceived brightness

HUE

chromatic aspect of color (red, blue, yellow, etc)

COLOR AFTERIMAGES

color flipped version of an image that remains after staring at one particular image for a while, fatiguing receptors

TILING

columns working together to ensure the entire visual field is covered

CONE DARK ADAPTATION BEHAVIOR

cones much less sensitive, greater operating range; need at least 10 photons per second, up to hundreds of thousands per second; recover sensitivity quickly

HORIZONTAL CELLS

connect photoreceptor cells horizontally; allow for lateral inhibition which lets ganglion cells react to information on differences in activation between groups of photoreceptors

UNIFORM CORRECTNESS

connected region of visual properties are perceived as single unit

ILLUSORY CONTOURS

contours that appear real but have no real physical edge

BEHAVIOR OF PATIENT WITH D.F.

damage to vertical pathway due to gas leak; not able to match orientation of card with slot but able to match orientation if placing card in slot -> double dissociation between ventral and dorsal pathways

OFF BIPOLAR

detection of decrease in light

ON BIPOLAR

detection of increase in light

NEAR POINT

distance at which the natural lens can no longer adjust for a closer object

ILLUMINATION EDGES

edges where lighting of two surfaces changes (different lighting, shadow)

REFLECTANCE EDGES

edges where the amount of light reflected changes between two surfaces (different material)

SIMULTANEOUS COLOR CONTRAST

effect that occurs when surrounding an area with a color changes the appearance of the surrounded area

COMMON REGION

elements in same region tend to be grouped together

PRAGNANZ/GOOD FIGURE/ SIMPLICITY

every stimulus is seen as simply as possible

SIMPLE CORTICAL CELL CHARACTERISTICS

excitatory and inhibitory areas arranged side by side. responds best to bars of a particular orientation

ON CENTER, OFF SURROUND

excited by central light, inhibited by peripheral light. When both center and surround stimulated a subtle response on ONset and OFF set; center OFF, ON surround is opposite

HYPEROPIA

farsightedness; eye too short, cannot focus on near objects

PERCEPTION

Act of giving meaning to a detected sensation

SINE WAVE GRATINGS

Amplitude (contrast); Frequency (cycles/degree); Phase; Orientation (rotation)

A researcher finds that damage to Area A in brain results in loss of Function A but not Function B. In another individual, damage to Area B results in loss of Function B, not to Function a. Results can be described as __________.

DOUBLE DISSOCIATION


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