PSYC 111 Exam 2

Opponent-color processing

-R, G, B colors are not independent but organized in pairs of opponent colors, red <--> green, yellow <--> blue, black<-->white These colors work in opposition of one another. It is a 3-color code and ganglion cells have 2 types of color sensitive cells known as red-green and yellow, blue. They respond in a center surround fashion although some ganglion only encodes brightness in the center and surround. Excitation of one-color causes inhibition of opponent color. When exposed for long periods of time to a color, firing rate adaptsContribution of cones: 1. Light: When red light is present, red cones hyperpolarize and that causes excitation within red, green ON ganglion cells which then signals red. 2. When green light is present, green cones hyperpolarize although cause inhibition within red ON ganglion cells.3. When yellow light is present, hyperpolarizes red and green cones. Exhibition and Inhibition cancel each other out in the red-green ganglion cells. In the yellow-blue ganglion cells they become excited and signal yellow 4. When blue light comes on, it inhibits yellow-blue ganglion cell and signals blue.

As we move around in the world, our eyes are constantly moving. Our brains, however, compensate for this movement. If the junction between the _______ lobes in the extrastriate cortex is damaged, individuals lose this compensation.

= temporal and parietal =

Which of the following is an explanation for the higher acuity of the visual system at the fovea, relative to the periphery of the retina?

A foveal ganglion cell may receive information from a single photoreceptor, whereas a peripheral ganglion cell may receive information from multiple photoreceptors.

How are adjacent cilia connected?

Adjacent cilia are connected with tip links.

Rate code of loudness for sounds

Axons of the cochlear nerve code loudness of a stimulus by changing their firing rate which means that louder sounds produce intense vibrations of the eardrum (ossicles have more force on the deflection of cilia) Hair cells release more neurotransmitter, producing a higher rate of firing by the cochlear nerve axons

Cell types of bipolar cells (on cells, off cells), ganglion cells (on cells, off cells, on/off cells), in primary visual cortex (simple cells, complex cells, hypercomplex cells)

Bipolar ON/OFF cells ON bipolar cells: Glutamate released from photoreceptors in the dark hyperpolarize ON bipolar cells. In the light, photoreceptors decrease glutamate release which causes ON bipolar cells to depolarize. (Activated by light). As glutamate is present it inhibits ON bipolar cells, K+ channels open, hyperpolarization OFF bipolar cells: Glutamate released from photoreceptors in the dark depolarizes OFF bipolar cells. In the light, photoreceptors decrease the glutamate release, and this causes the OFF bipolar cells to hyperpolarize. (Activated by darkness). Excitatory effect, when Na+ channel is activated, depolarization. Ganglion ON, OFF, ON/OFF cells ON ganglion cells: Excited (depolarized) by light falling in the central field (center) where there is an increase in activity. Inhibited (hyperpolarized) by light falling into the surrounding field (surround) where there is a decrease in activity. OFF ganglion cells: Inhibited (hyperpolarized) by light falling in the center field (center) there is a decrease in activity. Excited (depolarized) by light falling in the surrounding field (surround) there is an increase in activity. ON/OFF ganglion cells: Briefly excited when light was turned on or off, project primarily to the superior colliculus (signal motion and aren't involved in perception, responsible for blind sight) Primary visual cortex Simple cells: V1 neurons that respond to stimuli with particular orientations to objects within their receptive field. (clear excitatory and inhibitory regions) Complex cells: V1 neurons that respond optimally to a stimulus within a particular orientation. These types of cells respond to a variety of stimuli across different locations. Hypercomplex cells: These types of cells are selectively akin to complex cells and respond to moving of a stimulus of a specific orientation in a specific direction.

How airwaves enter the ear (describe parts of the outer ear) relative to sound perception.

First, the airwaves enter the Pinna (outer ear) Second, the airwaves are funneled through the ear canal Third, the airwaves then hit the tympanic membrane causing auditory motion

Differences between fovea and peripheral vision

Fovea: In this receptive field, this is the area of our vision that is all cones. We see majority of our world with clarity. Here we see a small amount of space in our visual world for each photoreceptor. The ratio is a 1:1:1, information goes through the three layers once. Peripheral vision: In this receptive field, it is much less precise than the fovea. The ganglion layer gets information from 6 photoreceptors.

Characteristics of visual stimuli: hue, brightness, saturation

Hue (wavelength of light): Determined by wavelengths. If there are slower oscillations, then there will be longer wavelengths. If there are faster oscillations, then there will be shorter wavelengths. Brightness: Determined by the intensity, it represents the amplitude of a wavelength. Saturation or purity: Determined by the purity of light, only one wavelength then it is fully saturated. If it is a mix of wavelengths, then no saturation it will be white.

Where does transduction take place in the ear?

In the Organ of Corti

_______________ cells are necessary for hearing, as demonstrated by the mutant mice who lack them and who, subsequently, cannot hear at all.

Inner hair

Characteristics of auditory stimuli: loudness, pitch, timbre

Loudness: Corresponds to the intensity of the stimulus Pitch: Corresponds to the fundamental frequency of the stimulus Timbre: Corresponds to the complexity of the sound

A _____ ganglion cell fires action potentials when there is a light stimulus moving through its receptive field.

ON/OFF

Describe the modular organization of V1, including orientation columns, ocular dominance columns, hypercolumns and color blobs.

Orientation column: A column of neurons that respond to one line orientation across all layers of primary visual cortex Hyper column: Contains ocular dominance column from both eyes across a full set of orientation columns Ocular dominance column: Contains a row of orientation columns that repersent all line orientations from a single eye (right or left) Color blobs: In the striate cortex information from color sensitive ganglion cells is transmitter through the parvocellular and koniocellular layers of the LGN, to the CO blobs (cytochrome oxidase). This structure houses neurons that are sensitive to color and have monocular receptive fields which means they receive visual information from only one eye.

Differences between rods and cones

Rods: 120 million, sensitive in dim light, black and white vision, concentrated in periphery, many-to-one neural connections, not sensitive to details Rods: Respond to low light situation, low acuity. More prevalent in Peripheral vision Cones: 6 million, not sensitive in dim light, color vision, concentrated in fovea, one-to-one neural connections, sensitive to details Cones: Responsible for our color vision, highly detailed

Parts of eye (orbit, sclera, cornea, iris, pupil, lens, retina, fovea, optic disk, etc...)

Sclera: Membrane around the eye, does not permit light and holds eye in place & moves the eye (saccades) Conjunctiva: Membranes merges with eyelid and protects the eye Cornea: Transparent outer covering admits light Iris: Pigmented ring (blue, green, brown) Pupil: Adjustable opening regulates amount of light Orbit: The bone cavity in the skull that houses the globe of the eye, the muscles that move the eye (extraocular muscles), the lacrimal gland, and the blood vessels/nerves required to supply these structures. Lens: Series of transparent, onion like layers. Changes its shape by contraction of ciliary muscles (accommodation- changes in the lens thickness that focus images of near or distant objects on the retina) Retina: 3 layered neural tissue that spans the back of the eye. Here is where phototransduction occurs, physical light stimulus is changed into an electrical potential. Fovea: Region of retina most acute vision, contains only cones. Optic disk: Exit point of optic nerve; causes a blind spot

Differences between the dorsal stream and ventral stream of visual processing (location/motion vs object/item) and their relation to damage produced deficits (akinetopsia, achromatopsia, etc...)

The Ventral stream (towards the chin): Information about "what" we are looking at is processed. Objects and colors are analyzed here. Also terminates inferior temporal cortex Visual agnosia: Deficits in the ability to perceive or identify objects in the absence of blindness Cerebral achromatopsia: Inability to discriminate among different hues The Dorsal stream: Analyzes the "where" information of the object. (location & motion) V5. MST: Responds to complex patterns of movement, including radial, circular, and spiral motion. Akinetopsia: Inability to perceive movement, caused by damage to area V5

How the movement of the middle ear is transduced into an electrical signal in the inner ear to the brain (describe parts of inner ear, including tip links and cilia).

The cilia attached to the hair cells react to sound in a specific way, they will move accordingly to the sound waves. The cilia rest against the tectorial membrane which is on top and basilar membrane on the bottom, when the shifting motion occurs the cilia will deflect. They do not have action potentials, but they release glutamate as a neurotransmitter and the more depolarized they are, the more glutamate is released. Glutamate only acts as an excitatory transmitter which causes action potentials in the cochlear nuclear cells.

How airwaves are amplified and communicated by the middle ear (describe parts of middle ear) relative to sound perception

The middle ear is composed of three bones (malleus incus, stapes) known as the ossicles; this is where sound vibrates in the eardrum. The malleus transmits the vibrations through the incus and stapes. The stapes pushes against the oval window which causes the inward movement within the fluid found in the cochlea. The oval window then starts to move in and out causing the fluid in the cochlea to move. Lastly, this makes the membrane at the round window to move in opposite directions.

Area ______ of the extrastriate cortex responds to movement.

V5

A neuropsychologist examines a patient with damage to her extrastriate visual cortex. The patient shows some deficits in color perception. Based on this information, the patient MOST likely suffered damage to area V4 or to area:

V8

How is the receptor potential created?

Vibrations transferred from sound waves move liquid within the cochlea that creates a shear force between the basilar and tectorial membranes of the cochlea. The shear force moves cilia which in turn open ion channels to create a receptor potential.

Simple cells in the primary visual cortex increase activation to __________.

a line of light in the center of its receptive field in the cell's preferred direction.

When Annie looks around the world, she only sees still images. She is unable to perceive her grandchildren running around or even her cat's breathing patterns. It is likely that Annie is suffering from:

akinetopsia

The ___________end of the basilar membrane specializes in processing ___________.

apical; low-frequency sound

Emma has tritanopia. When she looks around at the world, she sees shades of red and green. Her defect is caused by a lack of __________ cones

blue

There are three different cones that process different wavelengths of light. These wavelengths correspond to the colors:

blue, red, and green

When a photopigment is exposed to light, the pigment

breaks into an opsin and a retinal.

The "special function" of striate cortex neurons inside the CO blobs is BEST described as:

color sensitivity

Disparity-sensitive neurons in the ____ stream respond to large, extended visual surfaces.

dorsal

Matt is a baseball player. In order for him to catch a fly ball, his __________ stream must analyze information related to where the ball is located in space.

dorsal

The ________ in the brain is specifically activated by photographs, silhouettes, or stick drawings of human bodies or body parts.

extrastriate body area

The fact that adjacent regions of the basilar membrane and of the primary auditory cortex appear to respond best to different sound ________ can be displayed in a ________ map.

frequencies; tonotopic

In audition, a high frequency of vibration, as measured in hertz (Hz), would be perceived as a _____ sound.

high-pitched

Place coding for pitch indicates that ____________ frequencies are perceived when neurons of the basilar membrane become activated. Specifically, these neurons are located __________ the oval window.

higher; closer to

In an ON cell with a receptive field that contains a center and surround, light would cause excitation if light were shone:

in the center

in an OFF cell with a receptive field that contains a center and surround, light would cause excitation if light were shone:

in the surround

Which of the following matches is INCORRECT: inner ear -> oval window inner ear -> tympanic membrane middle ear -> ossicles outer ear -> pinna

inner ear -> tympanic membrane

If a blue-yellow ganglion cell is exposed to the color blue, it will fire in response to blue. If it is exposed to yellow:

it will become inhibited and, upon release of exposure to yellow, cause an after-image of blue

A complex cell located within the striate cortex would be most activated by a

line in its preferred orientation and moving perpendicular to the preferred orientation.

Neurons in the striate cortex are described as being sensitive to orientation. This means that they respond to:

lines at one particular orientation: vertical, horizontal, or somewhere in between.

The most important visual information is contained in _______ spatial frequencies.

low

What is the order of the ossicles from the tympanic membrane to the cochlea?

malleus, incus, stapes

Choose the correct match: middle ear -> tympanic membrane middle ear -> ossicles outer ear - > ossicles outer ear -> cochlea

middle ear -> ossicles

Because it is a nocturnal creature, an owl MOST likely has:

more rods than cones

A tip link connects two cilia. Movement of the cilia in the direction of the tallest cilia will:

open an ion channel.

The fact that we experience "after images", such as the flag shown in class, is taken as support for the

opponent-process theory of color vision.

Consider gustatory reception. The _____ contain _____, which in turn contain _____.

papillae; buds; receptor cells

The ________ in the brain is activated by the sight of scenes and backgrounds.

parahippocampal place area

The dorsal stream ends in the ________ cortex

parietal

In thinking of the pathways taken by visual information within the association cortex, the dorsal stream projects to the ________ and is involved in ________.

parietal association cortex; the analysis of "where" an object is located in space

The dorsal stream in the auditory cortex ends in the _____________ cortex and is involved in perception of a sound's _____________.

parietal; location

The __________ system receives information from the red and green cones, whereas the ___________ system receives information from the blue cones

parvocellular; koniocellular

When determining location of a sound, we use ___________ differences for low frequencies and ___________ differences for high frequencies.

phase; intensity

The frequency of an auditory stimulus refers to its ________.

pitch

Arlando experiences a stroke, and afterwards he is unable to visually recognize his loved ones, although he can recognize them when they speak. It is likely he has ________ caused by damage to ____________.

prosopagnosia; fusiform face area

In which order does light pass through the structures of the eye, from first to last?

pupil, lens, vitreous humor, retina

The perceived loudness of high-pitched sounds is determined by _________, and the perceived loudness of low-pitched sounds is determined by _______________.

rate of firing; the number of axons active at a time

In an experiment, various stimuli are presented to a cat in front of its eyes. Changes in firing rate are recorded from a neuron in the visual system. The part of the visual field to which a neuron responds is termed the

receptive field.

Retinal ganglion cells of the "ON" type

record an excitatory burst of potentials to a light placed within a circular center.

The area of the eye that contains the sensory receptors is called the

retina

When Jim looks at his raised finger, he can make it "jump" from one location to another by looking at it with only his left eye and then with only his right eye. Jim's illusory perception that his finger is in two different places successively BEST reflects:

retinal disparity

When you shift your gaze abruptly from one point to another, this motion is called ________ movement

saccadic

In a research experiment conducted by Johansson, actors dressed in all black and wore lights at key points on their bodies and then walked or moved. Patricipants could only see the illumination of the lights, not the actors themselves. Participants were able to determine the sex of the actors solely by the movements of their:

shoulders and hips

Research suggests that the taste sensation of saltiness is largely caused by receptors that are __________ channels.

sodium

Neurons in the _______ are sensitive to orientation of lines.

striate cortex

Which of the following is true about the place code of hearing:

the place on the cochlear membrane that is activated encodes frequency for sounds.

Which of the following is true about the rate code of hearing:

the rate code means that the higher the loudness the more action potentials are fired.

The visual pathway proceeds from:

the retina, to the LGN, to the striate cortex

In the striate cortex, neurons in CO blobs project to ________ stripes and send information about ________

thin; color

Disparity-sensitive neurons in the ___________ stream respond to contours of three-dimensional objects.

ventral

The extrastriate cortex, the _______ stream is responsible for identifying an object.

ventral

Visual agnosia, the inability to visually recognize objects, is caused by damage to the _____________ of the extrastriate cortex.

ventral stream

Which of the following areas would be considered extrastriate cortex?

visual association area 5 (V5)

Hair cell transduction of sound (cilium, tip link)

Cilium (cilia): A hair like appendage of a cell involved in movement or transduction auditory information Tip link: An elastic filament that attaches the tip of one cilium to the side of the adjacent cilium Movement of fluid in the cochlea in one direction causes tip link to stretch and there is an increase in neurotransmitter release in hair cell then causes an increase in action potentials in cochlear nerve axon. (excitation = high rate) Movement of fluid in cochlea in the other direction causes tip link to relax, there is a decrease in neurotransmitter release in hair cell and decrease in action potentials in cochlear nerve axon. (relaxation = low rate) As the fluid in the cochlea moves → cilium deflect causing depolarization in the hair cells → hair cells release glutamate → causes action potential in cochlea ganglion cells Insertional plaques: The point of attachment of a tip link to a cilium. Each contains a single cation channel (TRPA1). When cilia are straight, opening of the channel probability is 10% which means small amounts of K+ and Ca+ diffuses into cilium. When the cilia move toward the tallest cilium, increases tension on tip links which opens all the ion channels. The flow of cations into the cilia increases causing depolarization. The release of neurotransmitter increases. When the cilia move toward the shortest cilium, the relaxation of the tip links allows the opened ion channels to close, the influx of cations ceases, and the membrane hyperpolarize the release of neurotransmitter decreases.

The pathway of audition (cochlea ganglion cell ->medulla->midbrain->thalamus->primary auditory cortex)

Cochlea ganglion cell: The organ of Corti sends auditory information to the brain through the cochlear nerve which is a bundle of axons of bipolar neurons that send auditory information to the brain and reside in the cochlear nerve ganglion. The cochlear nerve ganglion cells have one end that acts like a dendrite and responds with the excitatory postsynaptic potentials when a neurotransmitter is released by the hair cells. This then triggers action potentials in the auditory nerve axons forming synapses with neurons in the medulla. Medulla: Cochlear nucleus and superior olivary complex: group of nuclei Axons will enter the cochlear nucleus of the medulla and synapse there. These neurons will send axons to the superior olivary complex and these axons of neurons will travel through the lateral lemniscus to the inferior colliculus in the midbrain. Midbrain: Inferior colliculus and lateral lemniscus (terminates here) After the axons of neurons pass through the lateral lemniscus and the inferior colliculus in the midbrain, the neurons send their axons to the medial geniculate nucleus of the thalamus. Thalamus: Medial geniculate nucleus After the neurons send their axons to the medial geniculate of the thalamus, it sends its axons to the auditory cortex of the temporal lobe. Primary Auditory Cortex: Area that is devoted to auditory processing When the axons arrive to the auditory cortex of the temporal lobe, each hemisphere of the brain receives information from both ears and some auditory information will travel to the cerebellum and reticular formation.

Parts of ear (outer: pinna, auditory canal, eardrum (tympanic membrane); middle: ossicles; and inner: cochlea, oval window, round window, organ of corti)

Outer Ear Pinna: Funnel sound wave down the auditory canal Tympanic membrane: Sound is funneled via the pinna through the ear canal to this structure (eardrum) Auditory canal: Carries sound wave down to the eardrum Eardrum: Vibrates when stimulated by sound waves Middle Ear Ossicles: 3 bones that set into vibration by the tympanic membrane and transmits the vibration to the cochlea. (magnify movement of tympanic membrane) Malleus (hammer): 1ST ossicles, attached to the tympanic membraneo Incus (anvil): middle ossicleso Stapes (stirrup): 3rd ossicles, attached to the oval window of the cochlea Inner Ear Inner cochlea: This structure is a boney structure (snail shaped) and is filled with fluid. It contains the basilar membrane and the auditory receptor hair cells. Sounds must be transferred from air to liquid medium. Oval window: Opening in the bone of the cochlea that reveals a membrane against which the baseplate of the stapes presses. It also works to transmit sound vibrations into the fluid within the cochlea Round window: Opening in cochlea moves in and out in a manner opposite to the movements of the oval window Organ of corti: A receptive organ for auditory sensation (take information to the brain) Basilar membrane: A membrane in the cochlea of the inner ear; contains the organ of corti Tectorial membrane: Serves as the shelf against which the cilia of the auditory hair cells move Hair cells: Sensory receptors Dieter's cell: Anchor's hair cells

Layers of the retina relative to back of eye and light (photoreceptors, bipolar cells, ganglion cells)

Photoreceptors: Transduces light into electrical potentials. Consists of: Rod: More sensitive to light but have low acuity, good in low light Cone: Maximally sensitive to 1 of 3 wavelengths (colors), highest sharpness (acuity), good in high light The only cells that are sensory receptors (respond to light) are the photoreceptors. In the light: Photoreceptors are hyperpolarized, decreases releasee of glutamate In the dark: Photoreceptors are depolarized, constantly releasing glutamate Bipolar cell: Gets information from the photoreceptors and convey it to the ganglion cells Ganglion cell: Axons form optic nerve carrying visual information to brain, only one that has action potentials Do not have the capacity to have action potentials (bipolar cells & photoreceptors) As they become depolarized, they release more transmitter

Place & Rate code of pitch (frequency) for sounds

Place code: Different frequencies (pitch) are coded by different locations (places) on the basilar membrane by the cochlea. (only works for greater than 200Hz) There are specific frequencies that can excite a specific har cells in the cochlea which leads to excitation of a particular auditory nerve causing more excitation in a specific region in A1 (auditory primary cortex). The place code is also represented in A1 as a Tonotopic representation which is an organized mapping of different frequencies in A1. In conclusion, higher frequencies are detected by the means of place coding Rate code: The lower frequencies are coded by the rate of firing action potentials of hair cells. (only works for less than 200Hz) No hair cells respond best to frequencies less than 200Hz Lower frequencies are detected by neurons that fire synchrony into the movements of the apical end of the basilar membrane In conclusion, lower frequencies are detected by the means of rate coding

Genetic disorders related to color

Protanopia: An inherited form of defective color vision in which red and green hues are confused. "Red" cones are filled with "green" cone opsin which is the first color defect. Deuteranopia: An inherited form of defective color vision in which red and green are confused. "Green" cones are filled with "red" cone opsin which is the second color defect. Tritanopia: An inherited form of defective color vision in which hues with short wavelengths are confused. "Blue" cones are either lacking or faulty which is the third color defect, and it affects fewer than 1 in 10,000 people.