Psychology Chapter 4

the gustatory system has 3 nerve tracts that connect the tongue to the brain

- after passing through a specialized gustatory region of the thalamus, taste information is directed to the primary gustatory cortex, located in the insular cortex, which is an extension of the somatosensory cortex that represents internal body states. - electrical stimulation in the insular cortex elicits taste sensations, and very strong stimulation can induce gagging and vomiting. - the information is also relayed to secondary taste regions in the adjacent orbitofrontal cortices that lie above the eye sockets

account rates of signal detection theory

- hits: responding "yes" when a stimulus is present - misses: responding "no" when a stimulus is present - false alarms: responding "yes" when no stimulus is present - correct rejections: responding "no" when no stimulus is present

night vision

- in the dark, all humans are color-blind - night vision is supported by a single type of photoreceptor with a single type of photopigment (the rods) - the peak sensitivity of rods photopigments is the blue-green range of wavelengths (wavelengths at the peak sensitivity of the rod photopigment will appear brighter at night, an effect called the Purkinje shift)

other smell facts

- most mammals have 2 nostrils - nostrils are used as 2 separate windows to the odor world - like auditory localization, smell localization appears to be supported in part by comparing the odor intensity between the 2 nostrils - when one of your nostrils is plugged, your odor tracking will be impaires - scent localization in humans is severely underdeveloped relative to that of other animals - odor tracking greatly improves with practice, however, suggesting that it may be a skill we have merely forgotten how to use - smell is still important for basic survival functions, such as smelling rotten food before eating it

information from the vestibular system can sometimes conflict with information from vision

- motion sickness when reading in the car. When you read, you are stabilizing images on the retina while you vestibular system says the world should be moving at high speed

depth perception intro

- one our brain has distinguished an object form its background, it has various means as its disposal for takin the 2D retinal image and translate it into a 3D perception of the real-world object - our brain has to use assumptions and inferences about the retinal image to regain depth information - the ability to perceive depth seems to be present early in development, as has been demonstrated in studies using a table whose surface is half opaque and half transparent glass ("visual cliff")

Cilia damage

- over a lifetime, the hairs can become damaged bc of overexposure to repetitive sounds or loud noises - cilia loss can occur at specific locations along the basilar membrane, creating hearing impairments for specific frequencies - ex: piano tuners who hear the same banging sound of notes day after day may experience selective hearing loss

place theory & frequency theory

- place theory best explains the perception of high-pitches sound, the sweet spot of our hearing range that include much of the range of the human voice - frequency theory best explains the perception of low-pitched sound

major sensations detected in the skin

- pressure - temperature - vibration - pain

amplitude (sound)

- related to the quantity of energy, and it corresponds with the intensity or loudness of the sounds we hear. - sounds with large amplitudes displace air molecules more than low-amplitude waves, and this large displacement in turn increases the perceived volume of the sound - measured in decibel (dB) units, which are determined by the ratio of pressure between different sounds

sequence of light into the eye

1) light enters the eye through the cornea (the transparent covering at the front of your eye) 2) light passes through the pupil 3) light also goes through the iris which gives the eye its distinctive color. The iris increases or decreases in size of the pupil depending on how light enters the eye 4) lens bends the light using accommodation

retina

A surface on the back of the eye that contains the photoreceptor cells - a multilayered surface that hosts the photoreceptors-the rods and cones-of the eye, critical for transducing light energy into electrical signals - eye focuses an image by adjusting the lens so that light is precisely focused onto a small region, called the fovea, in the retina

frequency theory (rejected by volley principle)

A theory of pitch perception that the brain uses the frequency of hair cells firing to indicate pitch. - ex: if a sound wave traveling at 20 Hz enters the cochlea, it will be transmitted to the auditory nerve by the hair cells at 20 pulses per second.

ventral pathway

The "what" pathway. travels along the temporal lobe - Pathway of visual processing. - Damage to the ventral stream impairs recognizing what an object is while leaving intact the ability to say where it is

dorsal pathway

The "where" (and "how") pathway. ultimately joins the parietal lobe - Pathway of visual processing. - flows upward to the parietal lobes - supports location, depth, motion, and thus influences how we interact with objects - Damage to dorsal stream don't know where it is or how to grasp an object, but they can recognize what it is. - perception of movement is processed in a specialized part of the dorsal pathway (middle temporal cortex/MT). helps know where things are as they are moving. Each MT neuron is tuned to respond to motion in a particular direction

When you watch fireworks on a dark night, the beautiful colors are vivid and bright. They seem to just jump out of the sky. What does this indicate about the fireworks, in terms of the physical properties of light?

They have a very high amplitude - High-amplitude light waves are perceived as being very bright and vivid.

A sound wave hits your left ear first and then hits your right ear a fraction of a second later. Given that your ears hear the sound at two different times, how do you experience this sound wave?

as a single sound, coming form your left - The brain can detect this tiny gap, but it doesn't split up your sensory experience into two sounds. Instead, it judges that the side the sound arrived at earlier must be the direction it was coming from, so you hear a single sound coming from your left.

achromatic colors

black, white, and grays; they do not result in a distinct color, or chromatic experience

eardum (tympanic membrane)

boundary line between the outer and middle ear - eardrum is a tight, skin-like membrane located approximately an inch into the ear canal that responds to sound wave vibrations by moving in and out with corresponding pressure changes - very sensitive and responds not only to pressure from vibrations of the faintest sounds but also the the intense pressure that can be felt when gaining elevation in an airplane or diving deep below the water's surface - connects to 3 of the tiniest bones in the human body

closure

We fill in gaps to create continuous edges, allowing us to perceive an object as a whole.

synchrony

We group items together that move at the same time. In audition, a similar effect takes place which is referred to as grouping by onset.

connectedness

We group together objects that are connected.

similarity

We group together things that look alike.

proximity

We perceive features as grouped when they are close together.

continuity

We tend to look for smooth, continuous patterns in objects. Similarly, while having a conversation we can partially ignore any interruptions and understand the sentences in a continuous manner.

How does the Gestalt principle of closure cause us to see shapes based only on their absence?

When gaps in several visible objects have edges that line up, we assume that those lines are part of an object that is obstructing our view

Monochromacy color blindness

a rare condition in which individuals are born with only one kind of receptor. Monochromatic individuals have no color perception - they see all wavelengths as various shades of gray

skin sensations are often caused by the activation of various combinations of receptor types

activation of both cold and pressure receptors leads to a sensation of wetness, whereas stimulation of both cold and warm receptors produces a burning sensation

olfactory association cortex

adjacent orbitofrontal cortices on the underside of the frontal lobes, but these evolutionarily newer cortical brain regions are not necessary for discriminating smells - an area that integrates olfactory information with associated behavioral, cognitive, and contextual information - represents the knowledge we have about the odor world, beyond what our nose knows. This knowledge includes names for smells and interactions with other senses, such as finding a specific odor appealing when looking at cheese but not so appealing when looking at feet.

retinotopically organized

adjacent portions of the retina connect with adjacent areas of the visual cortex - primary visual cortex is retinotopically organized - Your visual cortex re-creates a picture of the activity presented on your retina like a TV in your brain, albeit distorted, focusing primarily on your fovea through cortical magnification. Your visual cortex represents the foveal region as if it were looking at it through a high-powered magnifying glass.

accommodation

adjustment of the lens's thickness by specialized muscles in order to change the degree to which it bends light - as people age, the lens of the eye gets less elastic and the eye's ability to focus via accommodation weakens, making it difficult to see things that are too close - a condition called presbyopia

signal detection theory

an approach to measuring thresholds that takes into account both the intensity of the stimulus and psychological biases for a more accurate assessment. - one way to control the biases between conservative/liberal people is to include trials where no stimulus is present - distinguishes a conservative bias ("I don't hear anything yet") from a more liberal bias ("Sure, I hear everything"), allowing researchers to distinguish true perceptual sensitivity from other factors that might influence our responses

blind spot

an area in the middle of the visual field where there are no photoreceptors and no information can be received - your brain does not want you to know that you are blind, however, so it fills in the blind spot with information it gets from the surrounding regions of the retina - "white lie": what your eye does not sense, your brain can still perceive. your brain uses its beliefs about the world, given the surrounding context, to make you perceive what it thinks the stimulus must be.

the image of an object on our retina also varies dramatically in aspects such as hue and brightness as a result of changes in ambient light

changes in light throughout the day result in significant changes in the wavelengths reflected by an object - 2 people can see the very same dressk as black and blue or white and gold depending on the inferences their brain make about lighting at different times of the day - our brains' beliefs about the environment can result in dramatically different color perceptions of the same event

photopigments

chemicals in photoreceptors that are sensitive to light and assist in converting light into neural activity. - human eye uses a variety of these light-sensitive photopigments to pick up different wavelengths and convert them into electrical signals - human eye uses a variety of these light-sensitive photopigments to pick up different wavelengths and convert them into electrical signals - the range of wavelengths that these photopigments respond to determines what wavelengths of light that species can see-the visible spectrum

When you first see your beautiful prom date in her dress, you marvel at how green the material of her outfit is. Later, in the slightly darker auditorium where the dance takes place, the green color appears to be about the same even though surrounding light levels have changed. Which concept does this demonstrate?

color constancy - Color constancy is the phenomenon whereby the brain adjusts its perception of color to hold it constant, taking into account changes in lighting conditions.

cone cells

cone cells in the eye, which are responsible for our high-resolution color vision, are concentrated in a small pit at the center of the retina called the fovea

thermoreceptors

convert kinetic energy into action potentials that signal the sensation of temperature; respond to changes in temperature

tactile agnosia

damage to regions around the secondary somatosensory cortex, meaning one has an impaired recognition of objects from touch, but recognition of objects through vision remains intact - double dissociation reveals that we have distinct sense-specific object recognition systems in vision and touch that work in parallel

binocular cues

depth information gathered from the separation between an individual's two eyes. - separation allows the brain to receive 2 perspectives on the same event

monocular cues

depth information that can be gathered by only one eye. - animals whose eyes are positioned on the sides of their heads must rely on monocular cues only bc the images on the 2 eyes are entirely different - they cannot be compared. - monocular cues include relative size, relative height, interposition, linear perspective, and relative motion (which support depth perception)

About 1 in 50 people are color-blind. These people report seeing colors but can't tell certain colors apart (for example, distinguishing red from green). Which of the following terms describes their visual machinery?

dichromacy - Meaning "two colors," dichromacy happens when the visual system responds with peak intensity to two wavelengths of light. Two peaks are enough to differentiate some colors, but not all the colors most people experience.

Vision is a complex sense, and the eyes are remarkable organs for letting us see as much as we do. Which of the following statements about vision is correct?

each species has a different range of visual stimuli that their eyes can normally detect - Even in closely related species, like monkeys, the sensitivities of vision (such as telling colors apart) can differ dramatically. These differences are even more dramatic when comparing distantly related species, such as mammals and insects.

eye placement

eye placement has evolves so that predators have eyes in the front of their heads, allowing for binocular cues and greater depth perception. - Grazing animals have eyes placed on the sides of their heads to provide a larger visual field for detecting predators. - having 2 eyes contributes to our rich depth perception

Structuralism (Wundt)

first school of psychology based on the nation that complex perceptions can be understood in terms of their most basic parts or elements - focus was to find the fundamental building blocks of perceptual experience - in other words, to discover something like a periodic table of elements for perception

upside down principle

light rays that enter the eye are inverted on the retina, so that up versus down and right versus left are flipped. - if sight were entirely up to the eye and didn't involve the brain, when talking to your friends you would see them standing upside down and on the opposite side of the room. - the image on the eye is also 2D, bc the retina is a 2D sheet that can code only flat images - our brains use their experiences and smarts to recover much of what is lost on the retina so that we ultimately perceive an upright, 3D world.

tactile perception

is greatly influenced by expectation and the input from your other senses, especially vision. - skin sensations are usually perceived at the location of the receptor, but not always (rubber hand illusion: experimenter hides your hand and places a rubber hand on the table in front of you, strokes your hand and rubber had simultaneously, rubber hand seems to become your own. Vision tells your somatosensory cortex to shift its sensation to an area where receptors do not even exist) - not only about stimulation of touch sensory receptors but also about what your brain thinks you should feel

color purity

is related to the # of wavelengths that make up the light; it determines the perceptual quality of a color's saturation - eye can distinguish up to a few hundred spectral colors, which are based on a single wavelength or a small band of wavelengths - the smallest number of wavelengths = colors that are the most pure and vivid on the spectrum - when spectral colors are mixed together or with white light, this yields the vast range of color experiences we can distinguish - as purity and thus saturation decrease, colors fade to grey - the more wavelengths your visual system senses, the less color you will see

taste buds

little bumps on your tongue, each containing tiny invisible pores that catch food particles - within each of these pores are 50-100 taste receptors, each of which responds to 1 of the 5 kinds of taste molecules: sweet, salty, sour, bitter, savory (also called umami) - different sections of the tongue do not specialize in different tastes. instead, all taste sensations come from anywhere on the tongue. taste receptors can be found on the rook and back of the mouth as well. - spicy "heat" is not a taste but rather a somatosensory experience, similar to texture)

anosmia

loss of sense of smell - can happen from severed olfactory nerve through violent accidents if the head is snapped back and forth bc the olfactory nerve has to pass through tiny holes at the base of the skull called the cribriform plate

Dichromacy color blindness (having only 2 cones)

natural occurs in 1 in 50 people, often results from a deficiency in 1 of the 3 types of cones - allows for the perception of some color distinctions, but offers only about 1% of the variety a person with normal trichromacy has

neural refractory period

neurons need time between firing to produce new action potentials so cilia can fire about 1,000 times per second. - high-frequency sounds, which account for much of our auditory range, are too high for there to be a one-to-one correspondence, yet we can easily perceive sounds up to 6,000 Hz

sensory adaptation

occurs at the level of sensory receptors; a decrease in sensitivity to a constant level of stimulation - free us to focus on changes in our environment rather than on stimuli that are unchanging - olfactory receptors are very quick to adapt, making smell rapidly fade - sensory adaptation generally doesn't occur in our everyday visual experience bc our eyes move constantly and thus continuously change incoming stimulation

perceptual adaptation

occurs higher up in the brain; ability to adjust to an artificially displaced or inverted visual field - free us to focus on changes in our environment rather than on stimuli that are unchanging

aftereffects

opposing distortion that occur after adaptations - they are opposing bc you perceive the opposite of what your sense and brain have adapted to - ex: waterfall illusion: after gazing at a waterfall for about a minute, when you move your gaze away to the rocks, they appear to be moving upward - aftereffects are by no mean limited to the visual system - apply not only to simply sensations but also to our complex perceptions - ex: aspects of faces such as sex or emotional expressions are subject to the tuning effects of perceptual adaptation (staring at a smiling masculine face will shift an ambiguous face to look sad and feminine)

skin basics

our thin skin is the threshold between our outer and inner worlds. it is our largest. sensory organ. Our sense of touch is bother imperative to basic survival and socially enriching - touching one another serves as a critical role in reducing stress

nociceptor

pain receptor - a bare nerve ending that signals potential harm and causes a withdrawal reflec

middle temporal cortex/MT

part of the dorsal pathway where the perception of movement is processed. - some neurons will increase their firing response when an object is moving to the left, others when moving up or down; some even respond to complex radial motion - Damage to the MT area means akinetopsia: a deficit in perceiving motion, such that they experience the world as a series of static snapshots rather than a continuous flow of events

cones

photoreceptor cell that is responsible for high-resolution color vision

rods

photoreceptor cell that primarily supports nighttime vision

hierarchical analysis

process in which higher and higher levels of the brain create more and more complete representations fo what is out in the world - brain appears to make sense of the data it receives from the retina through this

primary gustatory cortex and insular cortex

processes taste information; located in insula - the primary gustatory cortex is located in the insular cortex. The insular cortex is also where the internal body states are represented, so it makes sense that taste, which occurs inside the mouth, would ablso be represented there.

Which sense enables one to know, without looking, that one's knee is bent?

proprioceptive - Proprioception is the sense of how each body part is arranged in relation to the rest.

feature detectors

specialized cells in the visual cortex that respond to basic features such as lines, edges, and angles with specific colors or movement. - neurons in the primary visual cortex - information from these feature detectors is collected and passed on to teams of cells in the secondary visual cortices (visual association cortex) where objects start to be reconstructed

flavor equals...

taste + smell - the combines activation of the olfactory receptors and taste buds produces an integrates flavor-speaking experience - complex interplay between our chemical senses is also due in part to the overlapping of olfactory and gustatory circuits in the brain

The ventral visual pathway travels along the ________ lobe of the cerebral cortex, while the dorsal visual pathway joins up with the ________ lobe.

temporal; parietal - The ventral pathway addresses questions of "what," and the dorsal pathway addresses questions of "where" and "how."

perception if probabilistic meaning...

that the transition from hearing to not hearing is gradual, rather than all or none.

ossicles

the 3 tinies bones in the body - the hammer, anvil, and stirrup - that acts as levers to amplify incoming sound waves. - form a bridge between the eardrum and another membrane called the oval window - eardrum connects to the hammer, which joins up with the anvil, which connects to the stirrup, which arrives at the oval window. - the ossicles act as levers amplifying the vibrations of incoming sound waves. this amplification is very important for our hearing, especially at small amplitudes, bc behind the oval window the inner ear is full of fluid, and fluid requires more energy to move than air does. If the sound waves were not amplified, the quieter sounds that we are capable of picking up would not move the oval window and would be inaudible - help protect the inner ear from extremely loud noises - cannot predict when sudden loud noises occur, so they don't help much when you are startled. but when you are at a sporting event, ur ossicles can act like a volume knob by adapting to noise amplitudes, reducing perceived sound up to 20 decibels

sensitivity

the ability simply to detect a stimulus is present

tonotopic organization

the arrangement of the auditory cortex such that nearby frequencies are processed near each other in the brain, resulting in sound map - higher frequencies are processed toward the back of the auditory cortex and lower frequencies toward the fron - when adjacent locations in the human auditory cortex are stimulated before neurosurgery, "nearby" pitches can be heard

According to the somatosensory homunculus, which of the following body parts has the largest dedicated portion of the somatosensory cortex?

the lips - The lips and hands are clearly the largest structures in the somatosensory homunculus.

size constancy

the phenomenon whereby the brain adjusts its perception of distance in order to perceive an object's actual size as constant, taking into account changes in retinal size - objects that are farther away project onto a smaller portion of the retina than closer objects of the same size

optic chiasm

the point in the brain where the visual field information from each eye "crosses over" to the appropriate side of the brain for processing - information from each of the optic nerves diverges, like trains switching tracks - axons coming from the left side of each retina are diverted to the left hemisphere of the brain. Axons from the right side of each retina are diverted to the right hemisphere of the brain. These axons arrive in a specialized visual nucleus of the thamalus and then continue on to the primary visual cortex (visual sensory receiving area in the occipital lobe)

middle ear

the portion of the ear containing the eardrum and ossicles

kinesthesis

the senses responsible for monitoring the position and movement of the body, including proprioception and the vestibular system - with practice, athletes gain an extremely fine-tuned awareness of their bodies and the tools that they use in sports, which allow them incredible control and precision

vestibular system

the sensory system primarily responsible for balance - consists of fluid-filled semicircular canals in the inner ear that relay information about body and head movements to the brain to help maintain balance, connected to the cochlea. movement of this fluid triggers hair cells that sense messages to the cerebellum - if you spin for a while and then stop quickly, it takes some time for the fluid in your inner ear to stop swirling

proprioception

the sensory system responsible for the awareness of body position - in pitch darkness, your body is not rendered blind but retains a sense of the position of its parts - tells you where to fumble for your keys and which direction the door is in - sensors in the joints, tendons, bones, ears, and skin enable you to know where parts of your body are in space and in relation to one another without having to visually check (alcohol can impair this)

acuity

the sharpness or specificity or perception, supporting the discrimination of stimuli. (n.) sharpness (particularly of the mind or senses)

glomeruli

the spherical cluster of neurons in the olfactory bulb - receptors in the glomeruli clusters are not randomly distributed. the bulb contains a patchwork of glomeruli - a map organized by receptor types, but this map is not clear yet bc during olfaction, many receptor types are simultaneously stimulated

detecting a stimulus depends on...

the strength of the stimulus and the perceiver's sensitivity as well as - psychological, situational, and personality factors (these can all cause problems for psychophysicists)

liberal response bias

the students who are motivated to get the highest score, so they say they hear everything, demonstrating hearing better than a dogs - respond "yes" more than "no" - more hits and false alarms

conservative response bias

the students with higher thresholds who are motivated to be accurate, so they don't say they have heard the tone until they are absolutely sure - respond "no" more than "yes" - in both cases, the respondents' true sensitivity may be the same, but it is masked by their biases - more misses and correct rejections

psychophysics

the study of the relationship between the physical characteristics of environmental stimuli and our mental experience of them. - scientist Gustav Fechner developed a set of methods to objectively measure people's subjective perceptual experiences

other race effect (ORE)

the tendency to see individuals of other races as more similar looking and harder to distinguish than people of one's own racial background. - this lapse in recognition arises from our brain's limited perceptual expertise - young children do not demonstrate the ORE, but as they develop increasing face recognition expertise up to early adulthood, the ORE emerges - the ORE may contribute to racism toward other people to whom we have little exposure and who therefore look different form "us". - seems to occur bc perceptual learning tunes our brain's neurons toward picking up on features that help us distinguish the kinds of individuals we have seen in our environment - ORE may be so powerful that it is similar to prosopagnosia, the severe deficit in facial identity recognition following brain damage, although the ORE results from lack of perceptual experience rather than from injury.

transduction

the transformation of sensory stimulus energy from the environment into neural impulses (then sent to brain via sensory nerves) - the process of transduction into electrical energy is different for each sensory organ - sensory-specific process of transduction such as light activates the receptors in your eyes and not the receptors in your ears

Gestalt principles (connectedness, closure, continuity, similarity, proximity, synchrony)

the visual system uses these rules to rapidly asses the environment and organize it into structured objects - we do encounter exception to the rules that can trick our visual systems into seeing situations that are impossible in reality

there are no colors in the world

there are only wavelengths - but humans perceive these different length waves of light as a distinct quality we call color

Which of the following scenarios depicts the influence of top-down processing in taste perception?

thinking that a $90 chocolate bar tastes better than a $1 chocolate bar, even if they are made of the exact same chocolate - The expectation that we are getting a higher-quality product can influence how we perceive its overall quality. This is top-down processing.

What is the process by which sensory energy is transformed into a set of neural impulses that are sent to the brain for interpretation?

transduction - Transduction comes after sensation and before perception.

weber's fraction

triangle I/I, where triangle - minimum change and I = physical intensity or magnitude of the stimulus - JND is captures in the Weber fraction (the ratio of the minimum change in magnitude of the stimulus to the overall magnitude of the stimulus)

2 major pathways in the visual brain

ventral and dorsal visual pathways - which originate from the retinal cones and rods - ventral pathway travels along the temporal lobe - dorsal pathway ultimately joins the parietal lobe

the sense of balance is informed by...

vision and the vestibular system - you can disrupt your sense of balance by cutting off visual information - your sensory systems are constantly conferring with and influencing one another to help you construct a more complete and informed picture of your surroundings than would be possible with any one sense alone.

ventriloquist effect

visual cues inform auditory signals so that they seem to come from the moving mouth of a dummy sitting in a ventriloquist's lap - a tendency to mislocalize heard sounds onto a seen source of potential sounds

basics of the properties of light on the color spectrum

wavelength = hue (large wl = red, small wl = purple) amplitude = intensity (too much = white, too little = black) color purity = grey to saturated hue (small to large) - i think frequency is inverse to wavelength

human ear structure

we rely on the structure of our ears to better funnel sound into the ear canal - our ears are separated into the outer, middle, and inner ear. the structures in the ear have evolved to collect and amplify air pressure waves and transduce them into sound - visible section of the ear: pinna or outer ear has evolved its shape to capture sound waves

Taste experience is multisensory

what we perceive as taste is actually a multisensory experience (touch, smell, hearing, sight) - when we eat, simultaneous stimulation of the mouth region of the somatosensory cortex evokes touch sensations in the mouth (texture plays a role too, not.just taste) - the experience of flavor itself does not occur on the tongue alone but is a combination of taste and smell - perceived crunchiness of foods like granola is mostly an auditory sensations - spicy "heat" is not a taste but rather a somatosensory experience, similar to texture)

McGurk Effect

when a speaker's lip movements actually change what we hear. - an error in perception that occurs when we misperceive sounds because the audio and visual parts of the speech are mismatched.

taste has important top-down influences, such as your expectation of food

you probably do a lot of exploring with other sensory systems before you place something in your mouth - telling someone it is more expensive, resulted in higher ratings - warning someone that it is savory, resulted in favorable ratings compared to not warning them where they strongly disliked it

relationship between ventral and dorsal pathways

*double dissociation between ventral & dorsal damage - they communicate with each other. How they communicate depends on focused attention

individuals can differ greatly in their taste experiences

- 2 synthetic substances, PTC and PROP, taste bitter to some people but are virtually tasteless to others - a small # of people are supertasters who find PTC and PROP unbearably bitter. supertasters are though to experience bitterness and other tastes more strongly. - the range of individual variation, from taste blindness to extreme sensitivity, largely reflects genetic differences in taste receptors on the tongue - food preference is clearly not all genetics. culture also teaches us what is safe - and pleasurable - to eat

different animals have a variety of sensory capabilities

- sensory capabilities have evolved through natural selection - in some cases, similar sensory organs provide very different perceptions. in other cases, very different sensory pathways provide similar perceptual informaiton. - although humans, mice, elephants all have similar auditory systems, each creature's system offers a different range of audition: - humans hear a middle range of frequencies (for speech recognition), mice hear higher frequencies (for ultrasonic vocalizations), and elephants hear lower frequencies (for long-distance sounds via the ground). most species have one dominant sense organ: -- humans are visual animals (Even tho other animals like birds of prey have much better vision than ours) - bears are known to be the best smellers on the land

Basics of Sound

- sound is derived form tiny vibrations that can travel through air, walls, and windows - when an object moves and vibrates, compressed and expanded air molecules create waves that exert pressure on the ear - evolution invented the ear to collect and transduce vibrations into neural energy, which the brain interprets as sound - although we call the waves created by the stimulus sound waves, the sound occurs not in the stimulus but only in the perceiver's mind - sound waves are being created constantly that we cannot tune in to bc our auditory receptors are sensitive only to a certain range of waves - our range of audition narrows with age, causing us to miss more of the high-pitches sounds in our environment - sound is derived from air pressure compression and expansion - sound waves are measured in the unit hertz (Hz): the number (or frequency) of completed wavelengths, or cycles, per second. - on average, humans can hear a range of frequencies from 20-20,000 Hz - the higher the frequency of a particular wave, the higher the sound's pitch - human voice ranges from 60-7,000 Hz (what we hear best)

perceptual learning with face recognition

- you are ale to recognize thousands of people bc of the minute differences in their features - sometimes fails us tho (other race effect)

movement of objects and the observer presents a tremendous source of sensory variability on the retina

- your eyes continuously jump rapidly from point to point to take in information. you unconsciously make approximately 3 of these shifts per second. - while your eyes shift or pursue, the world doesn't also seem to move around, making you dizzy. Instead, when the visual system is interpreting motion, it can subtract the motion caused by eye movements bc it receives feedback from the eye muscles - Your eye movements provide a great deal of information about your surroundings, but your brain needs to differentiate between the movement of objects in the environment and the movement of the observer

light energy to chemical energy

1) when light energy hits the photoreceptor cells, it causes chemical changes in their light-sensitive photopigments and changes their shape, which changes the flow of ions into and out of the photoreceptor cell body 2) this change in ionic concentration generates electricity, which is pass on to layers farther forward in the retina - the bipolar cells and then the ganglion cells - which fire action potentials when stimulated sufficiently. 3) to transform and process information in the environment, the photoreceptors first respond to light and generate electricity, which is sent to the bipolar cells. The bipolar cells organize and send their signals to the ganglion cell layer, which sends the signals to the brain 4) to travel to the brain, action potentials from the retina converge in a bundle of axons called the optic nerve, forming a thick cable that plugs the eye into the brain

While you are on vacation with your brother, he tells you about a psychological study he recently participated in. When he was holding a 50-gram weight, he couldn't tell that extra weight had been added until the added weight was more than 5 grams. According to Weber's Law, how much of your stuff can you add to his 25-kilogram suitcase without his noticing?

2.5 kilograms - According to Weber's Law, the just-noticeable difference in weight would be proportional to the starting weight. The ratio of 5 g to 50 g (in the study) is the same as 2.5 kg to 25 kg.

Akinetopsia (motion blindness)

A rare condition in which a patient is unable to detect motion despite intact visual perception of stationary stimuli, caused by damage to Area MT - don't see the movement fluidly from moment to moment

place-frequency map

According to place theory, frequency (pitch) depends on where the basilar membrane is stimulated, while amplitude (loudness ) depends on how much the basilar membrane is stimulated.

linear perspective (monocular cue)

As you may know from art classes, you can mimic distance by drawing a road with two straight lines that gradually converge. When we look at a real scene, parallel lines actually do appear to advance closer together until they are so far away that they reach what is called a vanishing point, where they converge. Instead of telling you the road is getting narrower, your brain uses this distortion of linear perspective to recover depth information.

Consider the following three letters: A B C. Suppose you are focusing your eyes on the B. Both your left and right eye can see the C, just off to the right of the B. Where in the primary visual cortex are your left and right eyes processing information about the C?

Both the left and right eye send information about the C to the left hemisphere of the primary visual cortex - The C is in the right visual field for both eyes, so both eyes send that information to the same brain region: the left primary visual cortex.

complementary colors

Colors located directly opposite one another on the color wheel (red-green, blue-yellow) - when opposing colors are placed next to each other, they stand out more - when mixing complementary colors, they cancel each other's appearance bc of mutual inhibition. Our eyes cannot combine these wavelengths to form a new chromatic experience, and what is left is an experience of some shade of gray rather than color.

Rosalia has a bad cold and is so congested that she can't breathe through her nose at all. What effect is this likely to have on her experience of food, and why?

Her ability to distinguish between flavors will be greatly reduced. - Our experience of food depends on many senses, including our taste and smell receptors, as well as the food's texture in the mouth. Without smell, differences we might normally be able to detect become invisible.

relative height (monocular cue)

If you drive by a field full of sheep, the sheep at the far end of the field will appear to be closer to the horizon because they project to a higher point in your visual field. You correctly perceive them as being farther away.

touch receptors are most sensitive to relative change

If you place your left hand in hot water and your right hand in cold water for 30 seconds, then place both in lukewarm water, your perceptions will tell you that your left hand is now cold and your right hand is now hot - even though the temp is the same for both. - explained through adaptation. adaptation sways the balance of the receptor responses - giving the illusion of different temperatures.

introception

Interoception involves receptors that monitor the state of our internal organs and relay information about them to the brain. It is primarily supported by the insular cortex, which is an extension of the somatosensory cortex. Sensing the physiological condition of the body; we have receptors deep in our bodies that allow us to feel sensations in our bones and organs - introception provides feedback to the brain about the internal physiological status of the body related to our vital organs - these receptors are esp. important for detecting internal pain and helping us consciously track abnormalities within our bodies - w/o introception, we might not know when to slow down on the treadmill when our heart hurts or when to go to the ER when our appendix bursts - supported in the insular cortex. it is an extension of your somatosensory cortex, appropriately located next to the tongue and esophagus sections, but it represents the mushy insides of your body

Which of the following is a primary limitation of the frequency theory of pitch perception?

It does not explain how the ear separates frequency (pitch) from amplitude (loudness) - Both the frequency and the amplitude of sounds can influence the frequencies at which hair cells fire, yet the frequency theory cannot explain our ability to sense frequency and amplitude separately.

taste receptor cells

Receptors that transduce gustatory information. - the sense of taste is mediated by taste receptor cells, which are bundles in clusters called the taste buds. - taste receptor cells sample oral concentrations of a large number of molecules and repot a sensation of taste to the brain

relative size (monocular cue)

Objects that are farther from you (such as the person in the distance) project a smaller image on the retina than those that are nearby (such as the person in the foreground). You can use your knowledge of the size of an object as a cue to judge its distance.

relative motion (monocular cue)

Relative motion, also known as motion parallax, provides excellent depth information. Objects that are very distant appear to move much more slowly because they are more stable on your retina than nearby objects. Rather than perceiving objects as moving slower or faster, your brain interprets them as differing in depth. As you well know, birds seem to move quickly across the sky, planes move slowly, and the moon hardly moves at all. Such perceptions are the opposite of these things' actual speeds and are attributable to their distance.

Which statement about the eye's blind spot is correct?

The blind spot is caused by an absence of photoreceptor cells - At the blind spot, the eye's neural wiring leaves no room for photoreceptor

Why does the fovea provide the highest level of visual acuity?

The fovea has the highest concentration of cones - The cones that are so abundant in the fovea are responsible for giving us crystal-clear vision, as well as color perception.

optic nerve

a bundle of axons that converge from the retina and transmit action potentials to the brain - connects the eye in a specific spot at the back of the retina - there is no room for photoreceptors where the optic nerve leaves the eye, which results in a blind spot

volley principle

The theory holding that groups of auditory nerve fibers fire neural impulses in rapid succession, creating volleys of impulses. - helps explain that neural hair cells alternate their firing rate to achieve faster combines frequencies - the cilia in the cochlea take turns firing so that they can respond to higher frequencies (instead of firing 1,000 times per second, it will only need to fire 250 times per second to transmit the same signal) - larger-amplitude sounds will increase the firing of the hair cells.

interposition (monocular cue)

When you are viewing one object that is partially blocked by another, you perceive the object behind the other to be farther from you. (It does not appear to be cut in half.)

Stefan is a 10-year-old boy. He doesn't get much sleep the night before visiting a neuropsychologist and performs poorly on the tests the doctor administers because he is tired. As a result of his poor performance, Stefan is diagnosed with a learning disorder. However, a test administered at a later time reveals that Stefan's ability to learn is normal after all. In signal detection theory, the initial diagnosis would be an example of which of the following?

a false alarm - Psychological assessments are reliable overall, but they are not perfect because any given test score is also subject to external randomness (such as a poor night's sleep). Stefan received a diagnosis (the "alarm") because the test made a mistake (hence the alarm being "false").

Homunculus

a maplike representation of regions of the body in the brain (little man creature) - each body area is represented proportionally to the amount of somatosensory cortex devoted to it, rather than to the actual body part size

lens

a membrane at the front of the eye that focuses the incoming light on the retina - bends light using accommodation

epithelium

a mucous membrane in the nasal cavity that contains the olfactory receptor neurons - enable human beings to discern about 1 trillion different odors! - researchers have not found a clear organizational system within the epithelium

After he was stung by a bee, young Eli became very nervous every time any flying insect was anywhere near him. Even if it was a common housefly, Eli would think it was a bee and would jump and run. What phenomenon influenced Eli's perception of the flying insects?

a perceptual set - A perceptual set, which is a part of top-down processing, is a predisposition that influences what we perceive based on recent experience or context.

foveation

a process where eye movements direct the fovea to a target

visual transduction

a process where the rods and cones convert light energy into electrical energy

Gestalt psychology

a school of psychological thought that attempted to explain how various elements group together to form objects, arguing that perception if more than a simple piecing together of building blocks - alternative framework to explain how the human brain groups various elements together to form objects. - attempted to define certain universal rules of thumb that the visual system uses to organize incoming data into meaningfully structured wholes - Gestalt principles are the basic rules that the visual system follows (connectedness, closure, continuity, similarity, proximity, synchrony). they provide a rough guide to the visual system's shortcuts for object recognition - the visual system uses

fovea

a small pit in the center of the retina that is densely packed with cones - during the day, most of what we experience in vision comes from the cones huddled in this tiny section of the retina - unconsciously, we know exactly where our fovea is- we use it all the time, moving your eyes so objects in the world fall on it. (necessary for reading) - your eyes are trained to move constantly in order to focus different stimuli directly onto the fovea, a process called foveation

cochlea

a spiral structure in the inner ear where the basal membrane, containing auditory sensory neurons, is located - critical transducer of the ear, turning fluid vibrations into neural energy - the coil of the cochlea is filled with fluid that is moved when ossicles push and pull the oval window

basilar membrane

a structure in the cochlea where the auditory cilia, or auditory sensory neurons, are located - contains thousands of hairlike cilia. Vibrations of the basilar membrane cause the cilia to bend back and forth, triggering neural impulses - like an elastic rubber band in your cochlea, to vibrate - more than 10,000 tiny cilia in each human ear, neatly organized into rows along the basilar membrane. - physical bending of the cilia, or hair cells, triggers neural impulses, similar to a hydroelectric dam that transforms the flow of water into electricity (cilia are extremely sensitive) - bending the cilia in one direction creates a depolarization of the hair cell bodies, making them more likely to fire action potentials. bending them in the opposite direction creates a hyperpolarization, making them less likely to fire

olfactory bulb

a structure just above the nasal cavity where information is communicated to the primary olfactory cortex via the olfactory tract - about the nasal cavity, beneath the frontal lobe - looks and serves a similar chemical-sensory function to the antennae of a slug - size of the olfactory bulb relative to the rest of the brain differs greatly across species, reflecting their use of smell, and is relatively tiny in humans

trichomatic theory

a theory of color perception stating that 3 types of cone cells, each most sensitive to a specific wavelength of light (short, medium, or long), work together to produce our perception of a multicolored world - developed by Thomas Young and Hermann con Helmholtz - any one color patch could be matched by the additive mixing of 3 lights of different wavelengths - long (red), medium (green), and short (blue) - all of our color experiences could be created by combining these 3 wavelength components - a single cone type cannot distinguish the precise wavelength and amplitude of light, so color perception requires the joining efforts of at least 2-3 cone types - the firing pattern across our 3 types of cones creates the final color judgment and experience in the brain: these multiple cone judges resolve other perceptual riddles as well, such as the fact that we can see the vibrant yellow of a lemon even though we don't have a "yellow" receptor

opponent-process theory

a theory of color perception stating that information from the cones is separated into 3 sets of opposing or opponent channels in the ganglion cell layer - explains the color afterimages as perceptual opposites - provides a physiological account of how colors are treated and perceived as opposites - a color afterimage is a perceptual opposite of the original color. - responses of the cones are combines in the bipolar and ganglion cell layers to create 3 sets of opposing or opponent color responses: white-black, red-green, and yellow-blue - color opponency is due to how bipolar cells combine inputs from the different cone types. ganglion cells that receive inputs from cones at the red vs. the green end of the wavelength cancel each other out. - as you stare at the original image, the cones' adaptation to the presented colors not only reduces perception of those colors but decreases the cones' ability to inhibit the opposing colors in the ganglion cells (the brain sees not only less of what the cones detect in that region but also more of its opposite)

place theory of pitch

a theory of pitch perception stating that different pitches arise from different places along the basilar membrane - Helmholtz proposed that high frequencies are felt by hairs at the beginning of the basilar membrane, where it is narrower and stiffer. low frequencies travel all the way through the coil to hairs on the tip of the basilar membrane, where it is wider and floppier - evidence supporting this was by Georg von Bekesy - the basilar membrane in your ear creates a place-frequency map. According to place theory, frequency (pitch) depends on where the basilar membrane is stimulated, while amplitude (loudness ) depends on how much the basilar membrane is stimulated. - lower-frequency sounds are not, however, as well organized on the basilar membrane as von Helmholtz had predicted

Prosopagnosia (face blindness)

a visual disorder in which individuals are unable to recognize the identity of faces (even those of family members and friends or their own reflection) - they can tell a face is a face and not some other object, but bc of all faces have two eyes, nose, mouth, etc. they appear more or less the same.

phi phenomenon

a visual illusion in which the flashing of separate images in rapid succession is perceived as fluid movement - what made the early days of Walt Disney magical (filmstrip)

localization basics

getting input from 2 ears located on opposite sides of our heads allows our brains to compare the relative timing (which comes first) and intensity (which is louder) between the sounds hitting each ear. the brain then uses this contrast to locate the origin of sounds in space - ex: if your friends were playing music in a dorm, sound localization would tell you which door to knock on - the brain is able to detect a 0.000027 second difference betwen the arrival of sound at one ear and at the other to determine the horizontal location of a sound - intensity of the sound also provides its own clues - your head casts a sound shadow, such that the ear farther away from the sound gets a slightly quieter version than the ear closer to the sound source - sound localization is much more accurate in humans for objects in front of us bc we can use visual feedback to tune the precision of our auditory localization

Max is sitting with his roommate, Gerald, watching a baseball game on television. Max notices that the broadcast has suddenly gotten very loud and asks Gerald to turn down the volume. Which physical quality of the sound waves coming from the television is responsible for Max's perception of increased volume?

higher amplitude - The amplitude of a sound wave is related to its volume, and higher amplitude would result in increased volume.

Which of the following phenomena does the opponent-process theory of color vision (but not the trichromatic theory) successfully explain?

how visual afterimages occur - Opponent-process theory holds that ganglion cells that are activated by one color (for example, green) also inhibit that color's opposite (for example, red). When a cone adapts to seeing the color green, the part that inhibits red also adapts, causing a visual afterimage of red when you look away from something green.

odor molecules fit into the receptor proteins of the cilia like a lock-and-key system

if enough odor molecules bind to their corresponding protein receptors, then an action potential is triggered, which travels down the bundle of receptor neuron axons that compose the olfactory nerve

visual agnosia

inability to recognize objects - patients with damage to the temporal lobe can perceive shapes and objects and can even draw them, but they fail to recognize what the objects are.

multisensory

integrating across sensory systems - our brains combines these signals to create a unified perceptual experience. Otherwise, our perceptions would be disconnected, dizzying, and chaotic

When you sit in your classroom, you can easily tell that your professor is closer to you than the blackboard is. This is because your view of the blackboard is obstructed by the shape of your professor's body. This demonstrates which visual depth cue?

interposition - This depth cue suggests that when you are viewing one object that is partially blocked by another, you perceive the object behind the other to be farther from you.

Hyperopia (farsightedness)

involves a near object overshooting the back of the eye, behind the fovea - result is an unfocused image on the retina and thus blurry vision (fixed by glasses, contact lenses, or surgery)

Myopia (nearsightedness)

involves faraway objects being projected too far in front of the fovea - result is an unfocused image on the retina and thus blurry vision (fixed by glasses, contact lenses, or surgery)

perceptual learning with language

is dramatically illustrated in language learning - your brain started out equally sensitive to all language sounds. After only 6 months of exposure to your soon-to-be-native language, your brain and perception started to adapt to the phonemes, the specific sound building blocks, of your native tongue - your perceptual abilities altered rapidly so that you as an infant became less sensitive to differences that were not relevant in your native language. perceptual changes in early childhood can also make it hard to distinguish non-native phonemes in adulthood.

inner ear

the innermost part of the ear, where the cochlea resides.

Isaac Newton and refraction

refraction: the bending of light rays through a prism - discovered that pure white sunlight contains all the colors we can perceive bc of the rainbow of colors visible to the human eye - objects are not colored but have differing capacities for absorbing and reflecting sunlight (leaves reflect the portion of the light spectrum that we see as green; white objects reflect the entire visible spectrum; black objects absorb the entire spectrum) - pure sunlight allows us to stay tuned to the changes and variations it produces as it bounces off objects in our environment, rendering them in vivid color - the fact that you see the world in color is an illusion due to the cortical magnification of information from the fovea, bc the majority of your visual field is color-blind

cortical magnification factor

regions that require finer discrimination (in this case, the fovea) receive more cortical representation - apportioning the small fovea with a large area on the cortex - pattern of less convergence and greater acuity in the cones is carried over to the brain - more direct connections (less convergence) in conjunction with more cortical space (cortical magnification) allow the cones in the fovea to convey more information (higher levels of detail) to the rest of your brain

secondary somatosensory cortex

represents more complex features, such as the sensation of motion on the skin, and enables the recognition of objects. - hapsis: examining an object by touch (supported by the somatosensory association cortex) - helps patients with visual agnosia (damage to visual association areas) bc even tho they can't recognize objects by sight, they can tell what an object it by its feel.

rods vs. cones

rods: - all the rods have the same type of photopigment - human eye contains about 120 million rod cells - nighttime: provide more sensitivity, primarily supporting nighttime vision, when light is limited and we see things in grainy shades of gray. - show high convergence (supporting sensitivity) - demonstrate a much greater degree of convergence, ultimately connecting many individual signals to one ganglion cell - provide only black-and-white information cones: - contain 1 of 3 varieties of photopigments (the multiple photopigments of the cones allow us to perceive colors; color vision only occurs in the cones) - human eye contains only 5 million cone cells - daytime: specialize in acuity, supporting daytime vision when light is abundant and we see things in high-resolution color - show low convergence (supporting acuity) - cones in the fovea have more of a 1-to-1 connection to cells farther down the line, showing less convergence onto the bipolar and ganglion cells - responsible for our color vision

What is the correct distinction between sensory adaptation and perceptual adaptation?

sensory adaptation occurs at the level of sensory receptors, while perceptual adaptation happens higher up in the brain - Sensory adaptation involves a reduced response by sensory receptors, while perceptual adaptation involves a reduced response by the brain to unchanging stimuli.

Rubin vase illusion

shows a 3D model of a famous image of either a vase or 2 faces - 2 component compete to be the dominant perceptual figure - your brain needs to settle its internal dispute about what it should perceive, so it picks one as the figure and relegates the other to the background

photons

the basic units of all forms of electromagnetic radiation. they have wavelike properties as they travel through space - our eyes transduce electromagnetic energy from the world into the neural energy of the brain, transforming light into sight - depending on its wavelength, electromagnetic radiation is classified into various types of waves, ranging from radio waves to gamma rays. - human eyes detect just a small sliver of the spectrum of electromagnetic energy (called the "visible" spectrum) - it is the property of the sensory receptors in our eyes that make them visible, not the wavelengths of light - humans have sensory receptors that are tuned to the range of wavelengths from 390-750 nanometers (one-billionth of a meter) but are blind to others

Which structure, found inside the cochlea, is vibrated by the movement of fluid and causes tiny hairlike structures to vibrate in turn?

the basilar membrane - When it receives input from the oval window, fluid inside the cochlea causes the basilar membrane to vibrate. Tiny hairs called cilia then register vibration at different points along the length of the membrane, telling the brain which wavelengths of sound the ear is receiving.

Ponzo illusion

the brain can use distance cues to influence the interpretation of size - when we see 2 objects. that project on the retina as the same size, but one appears to be farther away, we perceive the farther object as large - these assumptions, which override the retinal image to influence what you perceive, are developed through experience

perception

the brain's internal dialogue between our expectations and what our sensory receptors detect. - the same perceptual data can lead to different perceptions based on a person's mental perspective - such as seeing a glass half empty or half full.

color circle

the color circle is a more accurate representation of how we perceive color than the straight color spectrum is. Colors on the opposite side of the circle are perceived as most distinct. We also can see purple between red and blue, the high and low ends of the spectrum. - your visual system synthesized a novel color by combining the short-wavelength and long-wavelength ends of the spectrum - the blue and red cone photopigments - to fill the gap and complete the circle. (purple is considered a "psychedelic color bc it is a genuine hallucination of your brain)

iris

the colored muscle circling the pupil - gives the eye its distinctive color - can inc. or dec. the size of the pupil to adjust how light enters the eye (pupil appears black bc most of the light entering the pupil is absorbed)

wavelength

the distance between any two consecutive crests or troughs of a wave. - the wavelength of light determines our experience of color

amplitude

the height of a wave's crest - related to our experience of intensity or brightness, like the effect of a dimmer on a light switch - measure the quantity (brightness) of light

pupil

the hole in the iris where light enters the eye

binocular disparity

the magnitude of differences between the images projected on an individual's 2 eyes. - results in the brain seeing the world in "stereo," it produces the perception of 3D space by comparing the images projected on each eye. - ex: looking at a particular player on the baseball field: object is focused on the right and left fovea equally, so there is no binocular disparity, but the image of the other players are cast onto different positions in each retina, causing binocular disparity - the farther an object is from your line of focus (the fovea), the greater is the different between the images it projects on your 2 eyes. - this info is sent to the brain and contributes to your 3D stereovision. - movie and television use this to do 3D; many species have a larger visual field bc they have eyes on the sides of their head.

absolute thresholds

the minimum amount of stimulus necessary for someone to detect a stimulus half of the time - threshold is the opposite of your sensitivity - the lower the threshold, the higher your sensitivity - perceptual thresholds can change as a result of various factors (thus, graphed would look like an S) - thresholds are not static, but constantly changing (now you hear, now you don't)

difference thresholds (aka just-noticeable difference (JND))

the minimum difference requires between two stimuli for an observer to detect a difference half the time - Ernst Weber: difference thresholds increase as the stimulus size increases - perception of stimulus change is not a fixed absolute but a relative quantity - a percentage

auditory nerve

the nerve that carries impulses from the inner ear to the brain, resulting in the perception of sound - axons of hair cells from the cochlea are bundled together to form the auditory nerve - action potentials form the hair cells in the cochlea travel through the auditory nerve to the brainstem, which transmits the impulses through the auditory nucleus of the thalamus up to the primary auditory cortex

perception

the neural processing of electrical signals to form an internal mental representation inside your brain of what's on the outside. - further processing of these electrical signals (including organizing, constructing, interpreting sensory information) - although the eyes and other sensory organs detect stimuli, what the eye sees does not alone determine our conscious perceptions. - perception is the job of the brain, they are not direct copies of the sensory world - Perceptions are our brains' beliefs about the sensory world based on prior experiences and the present sensory evidence

frequency

the number of cycles per second of a wave - longer-wavelength light has lower frequency - shorter-wavelength light has higher frequency - measure the quality (color) of light

weber's law

the observation that the likelihood of perceiving a stimulus change is proportional to the magnitude of the stimuli - difference between 1-2 seems much larger than the difference between 9-10 - can be applied to our perception of any magnitude change - ratio rather than the absolute amount of the difference

Which of the following structures in the olfactory sensory system is the first along the pathway to display an organized structure, so far as we can currently tell?

the olfactory bulb - The epithelium sends signals to the olfactory bulb, and it is here that the first clear structure emerges in olfaction. Signals are sent to glomeruli, spherical clusters of neurons that respond differently to different types of stimulus.

pitch

the perceptual quality of sound that makes a flute sound high and a tuba low - change in the quality rather than the quantity of energy (contrasts with amplitude)

adaptation

the phenomenon whereby an individual stops noticing a stimulus that remains constant over time, resulting in enhanced detection of stimulus changes - with constant exposure to any stimulus, neurons fire less frequently - striking consequences of adaptation are aftereffects: opposing distortion that occur after adaptations

color constancy

the phenomenon whereby the brain adjusts its perception of color to hold it constant, taking into account changes in lighting conditions - you visual system can accommodate these shifts in illumination - the brain uses contextual cues to adjust its perception of color, taking into account the presence of shadows - it knows that the same color in the context of light vs. shadow should be perceived as different shades.

perceptual set

the predisposition that influences what we perceive based on recent experience or context. - mental predisposition that influences (from the top down) what we perceive based on the sensory inputs (from the bottom up) - using top-down perceptual hypotheses, our brains attempt to tell a coherent, complete story of our surroundings by taking into account recent experience or context, unconsciously biasing the way we perceive the world - emotional cues have a powerful influence on our perceptions, but even subtle environmental cues can lead us to make assumptions about what we might reasonably expect to see or feel - perceptual sets frequently influence our perceptions in the short term by using recent experience or context to guide our perceptions - over the long term, maintained sets can result in perceptual learning, causing enduring changes in how our brains support perception.

sensation

the process by which our sensory organs receive stimulus energies from the environment and convert them into the electrical energy of the nervous system (transduction) - sensations merge together in the brain to determine your perceptual experience of coffee

timbre

the quality of sound determined by complexity of waves - almost all sounds are made up of many cumulative waves - similar to the way the # of light wavelengths influences the purity of a color, the complexity of sound allows us to experience the psychological quality of timbre - explained by how we can tell two instruments apart even when they are playing the same pitch

primary somatosensory cortex

the region of the brain where the processing of touch sensations occur. - organized in such a way that sensations in particular body regions correspond to specialized adjacent regions of the cortex, consistent with a topographic representation (there is a somatosensory map of your hand in your brain) - larger regions of the body do not necessarily correspond to larger regions of the somatosensory cortex; instead, the most important areas get the most cortical real estate (tip of index finger gets much more representation than larger expanses of skin) Touch is processed in the somatosensory cortex. (b) It is organized according to the topography of the body, supporting a map of the entire body in the brain.

primary olfactory cortex

the region of the brain, located in the anterior temporal lobe, where smell is processed. - is the piriform cortex, and evolutionarily older cortical region on the inside of the temporal lobe that is adjacent to the amygdala and hippocampus. - olfactory sensations bypass the thalamus and connect directly with the primary olfactory cortex, as well as the components of the limbic system, suggesting that smells are linked with emotions (the amygdala) and memory (the hippocampus)

primary auditory cortex

the region of the brain, located in the temoral lobe, where sound is processed - place-frequency maps are found here too - adjacent places on the basilar membrane are represented in adjacent parts of the primary auditory cortex, making a "mind's ear" similar to a piano keyboard

visual association cortex

the region of the bran where objects are reconstructed from prior knowledge and information collected by the feature detectors. - located at the border of the occipital and temporal lobes (where the elements, or visual features, such as angles, lines, and edges are glued together and organized into basic shapes) - patients with damage to these brain regions are not blind but fail at drawing even basic shapes bc they have great difficult in organizing the details of their perception

olfaction

the sense of smell - a chemical sense bc the nose is designed to absorb airborne molecules - most complicated and puzzling sense - 1,000 types of receptor proteins embedded in the tiny hairs, called olfactory cilia, on the olfactory receptor neurons (which reside in the epithelium)

gustation

the sense of taste - a chemical sense bc the tongue relays information when it is stimulated directly by chemicals from food. - mediates what enters into our bodies and thus is the last line of defense against eating things that are bad for us (toxins, disease vectors) - we come into the world with robust taste preferences to protect our bodies and guide us toward nutrient-rich foods. - sweetness is associated with nutritious foods, and bitterness is associated with toxicity - culture does come to alter preferences tho - taste is derived from multiple receptors on the tongue - little bumps on your tongue are taste buds, each containing tiny invisible pores that catch food particles - as in the other sensory systems, the brain identifies a particular taste by the pattern of activation across recetor types

tacile sense

the sense of touch - perhaps the most obvious facet of our somatosensory system - determined by multiple receptors in the sin, or epidermis - each of these receptors is specialized to pick up and transduce a particular form of physical energy from the environment into electrical impulses, which are all sense in parallel and sent to the brain for analysis - major sensations detected in the skin are pressure, temperature, vibration, and pain