BioPsych Exam 3

Dichromats

people who only see two of the three primary colors; blind to read-green or blue-yellow; colorblind individuals

Cones

photoreceptors that detect color, operate under normal daylight conditions, and allow us to focus on fine detail

Blindspot

point at which the ganglion axons leave the eye as well as the blood vessels on the retina

Coding

-Temporal and anatomical one-to-one correspondence between some aspect of the physical stimulus and some aspet of the nervous system activity. -Translating the physical properties of a stimulus into a pattern of neural activity that specifically identifies those properties

What is the shape of the receptive field to which a simple cell in the primary visual cortex responds?

A bar in a particular orientation

The fusiform gyrus would be most excited in which of the following cases?

A car salesman looking at a customer's face

Photoreceptor

A light-sensitive cell located on the retina that converts light energy into neural impulses.

Lens

Focuses light in the back of the eye

Axons from the lateral geniculate extend to which area of the cerebral cortex?

Occipital Lobe

Damage to the dorsal stream may interfere with:

Reaching out and grasping an object.

Horizontal Cells

Retinal neurons that mediate lateral interactions between rods and the dendrites of bipolar cells to send info on the the Ganglion Cells

Rhodopsin

Rods-The pigment contained in rods that, through a chemical reaction, creates neural energy that allows rods to send messages.

Superchiasmatic Nucleus

SCN "Time clock", deals with sleep cycle and light and dark.

Light energy converts 11-cis-retinal to:

all-trans-retinal.

A person with visual agnosia is unable to:

recognize visual objects

Rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

Bipolar Cells

second layer of neurons in the retina that transmit impulses from rods and cones to ganglion cells

Specific Nerve Energies States-

that each sensory nerve responds to stimuli and sends the SAME action potential specific for that nerve. Actual Light and Pressure on Eyelid= "seeing" light

Optic Chiasm

the crossing of the optic nerves from the two eyes at the base of the brain

Optic Nerve

the nerve that carries neural impulses from the eye to the brain.

Opponent Process Theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. for example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

According to the law of specific nerve energies, the brain tells the difference between one sensory modality and another by:

which neurons are active.

Periphery

All the other space of the retina that contains rods which deal with movement

Sensation

Awareness of simple properties of stimuli; this si the first stage of input into the system; the biological reaction to a stimulus

Hypercomplex Cells

Cells in the visual cortex that respond to lines (bars, edges) in specific orientations and specific lengths; stimuli that are shorter or longer than the ideal length will produce a reduced response.

Iris

Colored muscle that controls the amount of light let into the eye

Lateral Geniculate Nucleus

Component of the thalamus that processes visual information from the eyes and sends this information to the primary and secondary visual cortex.

Iodopsin

Cones- 3 types that are sensitive to certain wavelengths of light

The visual path in the parietal cortex is referred to as the:

Dorsal Stream

T/F Magnocellular ganglion cells transmit information about an object's color

False

T/F Parvocellular cells respond strongly to moving stimuli and large overall patterns.

False

T/F Shapes are more easily identified with peripheral vision than foveal vision.

False

Simple Cells

Fixed excitatory & inhibitory zones. more light=more excite. Bar-shaped, used for mapping, respond to a line or an edge that is at a specific orientation and at a specific place on the retina

Fovea

Focal point of the eye, contains cones that respond well to detail, acuity.

Pupil

Hole within the iris that lets in light

While light is striking a visual receptor, light begins also to strike the receptor next to it. What effect will this additional light have on the response of the first cell?

Inhibition

Amacrine Cells

Integrate information from the bipolar cells for the Ganglion Cells. Refine input for shapes & movement

Suppose someone has a genetic defect that prevents the formation of horizontal cells in the retina. Which visual phenomenon is most likely to be impaired?

Lateral Inhibition

Retina

Lining of the back of the eye

Complex Cells

Located in either V1 or V2, large receptive field. Cells in the visual cortex that respond mainly to lines (bars, edges) in specific orientations, but are insensitive to the exact location on which the stimulus falls within their receptive field.

What type of cell responds to a pattern of light in a particular orientation anywhere within its large receptive field, regardless of the exact location of the stimulus?

Simple

T/F Lateral inhibition is the reduction of activity in one neuron by activity in neighboring neurons.

True

Cortical area ____ appears to be where conscious visual perception occurs.

V1

The visual paths in the temporal cortex collectively are referred to as the:

Ventral Stream

Trichromatic Theory

Visual theory, stated by Young and Helmholtz that all colors can be made by mixing the three basic colors: red, green, and blue; a.k.a the Young-Helmholtz theory.

Superior Colliculus

aspect of the tectum of midbrain associated with visual reflexes and tracking movements of the eyes.

Perception

based on sensation as well as expectations; second stage of input.

Transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

Because blood vessels and ganglion cell axons are almost absent near the ____, it has nearly unimpeded vision.

fovea

Colorblindness

inability to see certain color combinations: red-green or blue-yellow; 10% are male and 1% are female

Monochromats

individuals who see no color at all; respond only to shades of light and dark; very rare

The ability to detect movement better than color in our peripheral vision is largely due to:

magnocellular neurons in the periphery.

One might find cells that respond best to the movement of an object relative to its background in the:

medial superior temporal cortex.

Ganglion Cells

neurons that connect the bipolar cells to the optic nerve; an interneuron; one million in each eye; summarizes and organizes data from rods/cones and sends it to the brain

____ modify the ____ sensitivity to different wavelengths of light.

opsins; photopigments

Cornea

transparent membrane that covers the eye to protect it as well as bend light