Biopsych Chapter 6

About ___of the axons of retinal ganglion cells become part of the retina-geniculate-striate pathways.

* 90 percent 50 percent 80 percent 70 percent

__________________ is a visual agnosia for faces.

* Prosopagnosia Maskitis Facial agnosia Akinetopsia

Convergence is greatest when inspecting things that are

* close. in the periphery. far. small.

Binocular disparity tends to be greater for _________ objects

* closer distant larger smaller

The mechanism of contrast enhancement is

* lateral inhibition. cytochrome oxidase. retinex. Mach bands

Ciliary muscles adjust the

* lens shape. pupil size. binocular disparity. foveal size.

According to the ____________ theory, if an increase in the response of a particular visual neuron signals green, a decrease signals red.

* opponent spectral retinex component

_______________ neurons are particularly responsive to color, fine pattern details, and stationary or slowly moving objects; in contrast, ________________ neurons are particularly responsive to movement.

* parvocellular; magnocellular ganglion; amacrine magnocellular; parvocellular amacrine; ganglion

Damage to the fusiform face area is often associated with

* prosopagnosia. blindsight. blockage of the dorsal stream. akinetopsia

Persons with a visual agnosia

* see objects but can't identify them. have little or no visual memory. have damage to the ventral prestriate cortex. are unaware of one side of their body.

When the pupils are constricted, the image falling on each retina is ___________ and there is a greater ____________

* sharper; depth of focus sharper; accommodation blurrier; accommodation blurrier; depth of focus

The main difference between simple cortical cells and lower layer IV neurons is that the borders between the "on" and "off" regions of the receptive fields of simple cortical cells are ____________ rather than ______________.

* straight; circular straight; wavy excitatory; inhibitory circular; straight

______________ vision predominates in good lighting and provides high-acuity colored perceptions of the world. In contrast, the more sensitive ______________ vision predominates in low lighting.

Ganglion-cell-mediated; bipolar-cell-mediated * Photopic; scotopic Scotopic; photopic Rod-mediated; cone-mediated

______________ vision predominates in good lighting and provides high-acuity colored perceptions of the world. In contrast, the more sensitive ______________ vision predominates in low lighting.

Ganglion-cell-mediated; bipolar-cell-mediated * This effect can be observed during the transition from photopic to scotopic vision.Photopic; scotopic Scotopic; photopic Rod-mediated; cone-mediated

_______________ refers to the ability of certain patients to respond to visual stimuli in their scotomas even though they have no conscious awareness of the stimuli.

Unconscious sight Scotomata * Blindsight Hindsight

_________________ is a deficiency in the ability to see movements progress in a normal, smooth fashion.

Visual tremor Motionopsia * Akinetopsia Prosopagnosia

_________________ constancy refers to the fact that the perceived color of an object is not solely a function of the wavelengths reflected by it.

Wavelength Perceptual Reflective * Color

Many persons with scotomas

are always consciously aware of their deficits frequently complain of being confused by the deficits in their visual field. often report seeing images that are not actively present in their visual field. * are not consciously aware of their deficits.

All signals from the right visual field reach the left primary visual cortex, either ipsilaterally from the _______________ of the left eye or contralaterally from the ____________ of the right eye

bipolar cells; ganglion cells ganglion cells; amacrine cells nasal hemiretina; temporal hemiretina * temporal hemiretina; nasal hemiretina

Because of the way that it is organized, the visual system is referred to as

blob-like. * parvocellular. retinotopic. prestriate.

At least two parallel channels of communication flow through each lateral geniculate nucleus. One runs through the ______________ layers and a second runs through the _____________ layers.

blob; non-blob on-centered; off-centered * parvocellular; magnocellular simple; complex

The major advantage of the retinex theory over the classic component and opponent process theories of color vision is that the retinex theory

can explain the perception of blobs. can explain Mondrians. is newer. * can explain color constancy.

The ___________________ of a visual neuron is the area of the visual field within which it is possible for a visual stimulus to influence the firing of that neuron.

dendrites * receptive field firing zone firing field

In situations where the level of illumination is high and sensitivity is not important, the visual system responds by

dilating the pupils of the eyes. * constricting the pupils of the eyes. downgrading the arousal level of other sensory systems working in tandem with input from the eyes. habituating to stimulation of the retinas of each eyes.

Rhodopsin is a(n) ____________________ that responds to light rather than to neurotransmitter molecules.

dopamine receptor cell * -protein-coupled receptor ion channel

Unlike simple cortical cells, which are all _______________, many complex cortical cells are _____________.

excitatory; inhibitory binocular; monocular inhibitory; excitatory * monocular; binocular

When we direct our gaze at something ___________, the lens tends to assume its natural _____________ shape.

far; cylindrical far; conical near; conical * near; cylindrical

Which of the following cell types are in the human retina?

ganglion cells bipolar cells horizontal cells * all of the above

Which of the following are involuntary fixational eye movements?

ganglions amacrines scotopics * saccades

In comparison to simple cortical cells, complex cells

have larger receptive fields. do not have receptive fields with static "on" and "off" areas. are often bilateral. * all of the above

On-center and off-center cells respond best to

high illumination. low illumination. consistency. * contrast

The middle temporal (MT) area of human cortex appears to play an important role in the perception of

illusions. depth. * motion. faces.

When rhodopsin is exposed to continuous intense light

it loses its red coloring. it loses its ability to absorb light. it becomes bleached. * all of the above

Visual signals from the left nasal hemiretina are projected directly to the

left nasal hemicortex. * Lateral geniculate nuclei. lateral network. right nasal hemicortex.

Although the _________ constitutes only a small part of the retina, a relatively large proportion of the primary visual cortex is dedicated to the analysis of its output

nasal hemiretina * fovea blind spot periphery

According to one theory, the dorsal stream is involved in the perception of __________________ and the ventral stream is involved in the perception of ___________________.

objects; faces what objects are; where objects are * where objects are; what objects are faces; objects

When an ommatidium fires, it inhibits its neighbors; this inhibition is called

ommatidial inhibition. bad neighbor inhibition. lateral suppression. * lateral inhibition

According to the ___________ theory of color vision, the color of an object is determined by its reflectance.

opponent spectral component * retinex

The fovea

plays an important role in photopic vision. is an indentation. contains the highest density of cones. * all of the above

Most areas of secondary visual cortex are located in two general regions: the _______________ and the __________________.

prefrontal cortex; inferotemporal cortex * prestriate cortex; inferotemporal cortex inferotemporal cortex; striate cortex inferotemporal cortex; prefrontal cortex

According to the ____________ theory, there are three different kinds of color receptors, each with a different spectral sensitivity.

retinex spectral * component opponent

Photopic vision is

rod-mediated. * cone-mediated. achromatic. limited to the periphery of the retina

The retina-geniculate-striate system is _____________. This means two stimuli presented to adjacent areas of the retina will excite adjacent neurons at all levels of the system.

stratified parallel * retinotopic excitatory

The process of adjusting the configuration of the lenses to bring images into focus on the retina is called

stretching. * accommodation. focusing. adjustment.

Most primates are ______________, whereas most other mammals are _______________.

tetrachromats; trichromats trichromats; tetrachromats * trichromats; dichromats dichromats; trichromats