Psychology Assignment 3

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Physiology of Behavior

Twelfth Edition

Chapter 6

Vision

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Chapter 6 Preview

The Eye

Brain Regions Involved in Visual Processing

Perception of Color

Perception of Form

Perception of Spatial cation

Perception of Orientation and Movement

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Learning Objectives (1 of 5)

6.1 Differentiate between sensation and perception.

6.2 Describe visible light, hue, saturation, and brightness in the perception of light.

6.3 Identify the structures of the eye and describe their function in visual processing.

6.4 Contrast the cation and function of rods and cones.

6.5 Describe the process of transduction of visual stimuli including the role of photopigments and bipolar cells.

6.6 Compare the characteristics of central and peripheral vision, including receptive fields and eye movements.

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Learning Objectives (2 of 5)

6.7 Explain how stimuli are conveyed to the brain through the optic nerves.

6.8 Describe processing of information in the visual pathway, including the roles of the striate and extrastriate cortex.

6.9 Describe the pattern of retinal ganglion cell input and the layers of the LGN.

6.10 Identify the role of the striate cortex in visual processing, including functions of visual field mapping, CO blobs, and modular organization.

6.11 Identify the role of the extrastriate cortex in visual processing, including the dorsal and ventral streams.

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Learning Objectives (3 of 5)

6.12 Compare the activity of ON, OFF, and ON/OFF retinal ganglion cells in response to light.

6.13 Differentiate between the trichromatic and opponent-color system theories.

6.14 List the contributions of the parvocellular and koniocellular systems to perception of color in the striate cortex.

6.15 Using examples from human and animal research, describe the role of the extrastriate cortex in color perception and achromatopsia.

6.16 Examine the benefit of neural circuits that analyze spatial frequency in the striate cortex.

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Learning Objectives (4 of 5)

6.17 Use examples from the research literature to support the roles of the ventral stream and fusiform face area in perception of form.

6.18 Identify the retina’s contributions to perception of spatial cation.

6.19 Describe the contributions of retinal disparity, and the dorsal and ventral streams to visual perception of spatial cation.

6.20 Discuss examples from the research literature that support the role of the extrastriate cortex in perception of spatial location.

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Learning Objectives (5 of 5)

6.21 Explain how cells in the striate cortex identify orientation and function as movement detectors.

6.22 Describe the roles of region V5, MSTd, and the extrastriate body in the perception of movement.

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The Eye

Sensation

Cells of the nervous system detect stimuli from environment

Perception

Conscious experience and interpretation of information from the senses

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Vision

Perceptual Dimensions of Color

Hue: Dominant wavelength

Brightness: Intensity

Saturation: Purity

Perceptual Dimensions of Cor

Hue: Dominant wavelength

Brightness: Intensity

Saturation: Purity

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The Stimulus

Sensory Receptors

Specialized neurons

detect a particular category of physical events

Sensory Transduction

The process by which sensory stimuli are transduced into slow, graded receptor potentials

Receptor Potential

A slow, graded electrical potential produced by a receptor cell in response to a physical stimulus

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Figure 6.2 The Electromagnetic Spectrum

Figure 6.2 page 153

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Anatomy of the Eye

Retina: Neural tissue and photoreceptive cells located on the inner surface of the posterior portion of the eye

Photoreceptors: One of the receptor cells of the retina that transduces photic energy into electrical potentials

Rod: One of receptor cells of retina; sensitive to low intensity light

Cone: One of receptor cells of retina; maximally sensitive

Retina

Neural tissue and photoreceptive cells cated on the inner surface of the posterior portion of the eye

Photoreceptors – one of the receptor cells of the retina; transduces photic energy into electrical potentials

Rod – sensitive to light of w intensity

Cone – maximally sensitive to one of three different wavelengths of light and hence encodes cor vision

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Figure 6.3 The Eye

(a) The extraocular muscles move the eye. (b) The anatomy of the eye.

Figure 6.3, page 154

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Photoreceptors (1 of 2)

Fovea (foe vee a)

Region of the retina

Mediates most acute vision of birds and higher mammals

Color-sensitive cones only type of photoreceptor found in fovea

Optic Disk

Location of exit point from retina of fibers of ganglion cells that form optic nerve

Responsible for blind spot

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Photoreceptors (2 of 2)

Other Cells of the Retina

Bipolar Cell: Bipolar neuron located in the middle layer of the retina, conveying information from the photoreceptors to the ganglion cells

Ganglion Cell: Neuron located in the retina that receives visual information from bipolar cells; its axons give rise to the optic nerve

Horizontal Cell: Neuron in the retina that interconnects adjacent photoreceptors and the outer processes of the bipolar cells

Amacrine Cell: Neuron in the retina that interconnects adjacent ganglion cells and the inner processes of the bipolar cells

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Figure 6.4 Layers of the Retina

The human retina contains layers of ganglion, bipolar, and photoreceptor cells.

Figure 6.4 page 154

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Figure 6.5 A Test for the Blind Spot

With your left eye closed, ok at the plus sign with your right eye and move the page nearer to and farther from you. When the page is about 20 centimeters from your face, the green circle disappears because its image falls on the blind spot of your right eye.

Figure 6.5, page 155

Figure 6.6 Details of Retinal Circuitry

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Figure 6.6, page 156

(Adapted from Dowling, J. E., and Boycott, B. B., Organization of the primate retina: Electron microscopy, Proceedings of the Royal Society of ndon, B, 1966, 166, 80–111.)

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The Eye Transduction (1 of 2)

Transduction: energy from environment converted to change membrane potential

Photopigment embedded in lamellae

Rod: 10 million photopigment molecules

Opsin

Retinal

Vitamin A

lamellae: thin plates of membrane that make up the outer segment of photoreceptors

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The Eye Transduction (2 of 2)

Photoreceptors

Photopigment

Opsin (opp sin)

Retinal (rett i nahl)

Rhodopsin (roh dopp sin)

Photopigment

Protein dye bonded to retinal, a substance derived from vitamin a; responsible for transduction of visual information

Opsin (opp sin)

Class of protein that, together with retinal, constitutes the photopigments

Retinal (rett i nahl)

Chemical synthesized from vitamin A; joins with an opsin to form a photopigment

Rhodopsin (roh dopp sin)

Particular opsin found in rods

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Figure 6.7 Neural Circuitry in the Retina

Light striking a photoreceptor produces a hyperpolarization, so the photoreceptor releases less neurotransmitter. Because the neurotransmitter normally hyperpolarizes the membrane of the bipolar cell, the reduction causes a depolarization. This depolarization causes the bipolar cell to release more neurotransmitter, which excites the ganglion cell.

Figure 6.7, page 156

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Central and Peripheral Vision

Receptive field: the place a visual stimulus must be located to produce a response in that neuron

Foveal versus peripheral acuity (next slide)

Types of eye movements

Vergence movements

Saccadic movements

Pursuit movement

Vergence movements are cooperative movements that keep both eyes fixed on the same target

jerky saccadic movements—you shift your gaze abruptly from one point to another

Pursuit – folw moving object

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Figure 6.8 Foveal versus Peripheral Acuity

Ganglion cells in the fovea receive input from a smaller number of photoreceptors than those in the periphery and hence provide more acute visual information.

Figure 6.8 page 157

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The Optic Nerves

Axons of retinal ganglion cells bundle together to form the optic nerve

Conveys information to the dorsal lateral geniculate nucleus (LGN)

Optic chiasm and Blindsight

Note the effect of optic chiasm on visual field – see diagram on next slide

Blindsight is a phenomenon in which cortical regions involved in conscious perception of visual stimuli are damaged, but other visual pathways that are not involved in conscious perception are intact. The case of Mr. J.(in text) illustrates the symptoms of blindsight

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Figure 6.9 The Visual Field

Figure 6.9 page 158

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Overview of the Visual Pathway

Photoreceptors in Retina

Synapse with bipolar and retinal ganglion cells

Ascend through optic nerves to LGN

LGN sends axons to primary visual cortex (V1)

Visual Association Cortex (V2)

V1 also known as striate cortex

V2 also known as extrastriate cortex

More complex aspects of visual processing occur in additional areas, such as V4 and V5

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Figure 6.10 The Visual Pathway

The visual pathway begins with photoreceptors in the retina, which send information to the LGN through the optic nerves. From the LGN, visual information is conveyed to the visual cortex.

Figure 6.10 page 159

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Brain Regions Involved in Visual Processing: Lateral Geniculate Nucleus

The LGN is composed of six layers of cells.

Lateral Geniculate Nucleus (LGN)

6 layers of neurons

Layers 1, 4, 6 receive input from contralateral eye

Layers 2, 3, 5 receive input from ipsilateral eye

Magnocellular layers

Parvocellular layers

Koniocellular layers

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Figure 6.11 Lateral Geniculate Nucleus

The LGN is composed of six layers of cells.

Figure 6.11 page 161

Magnocellular Layer – One of inner two layers of neurons in dorsal lateral geniculate nucleus; transmits information necessary for perception of form, movement, depth, and small differences in brightness to primary visual cortex

Parvocellular Layer – One of the outer four layers of neurons in the dorsal LGN, which transmit information necessary for perception of cor and fine details

Koniocellular Sublayer –One of the sublayers of neurons in the dorsal LGN found ventral to each of the magnocellular and parvocellular layers; transmits information from short-wavelength (blue) cones to the primary visual cortex

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Striate Cortex (1 of 2)

Nobel Prize winners: David Hubel and Torsten Wiesel

Neurons respond to specific features (contours)

Visual cortex combines information from several ganglion cells

Allows detection of features larger than receptive field

The retinal ganglion cells encode information about the relative amounts of light falling on the center and surround regions of their receptive fields

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Striate Cortex (2 of 2)

Layers

6 layers arranged in bands parallel to the surface

Cytochrome Oxidase (CO) Blobs

Process info from color sensitive ganglion cells

Found in layers 2 and 3, faintly in layers 5 and 6

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Figure 6.12 Layers of the Striate Cortex

Figure 6.12 page 162

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Figure 6.13 Blobs and Connections in V1 and V2 (1 of 2)

(a) A photomicrograph (actually, a montage of several different tissue sections) showing a slice through the striate cortex (area V1) and a region of visual association cortex (V2) of a macaque monkey, stained for Cytochrome oxidase. Area V1 shows spots ("blobs"), and area V2 Shows three types of stripes:. thick, thin(both dark), and pale.

Figure 6.13 page 162

(Froth Sincioh,L C., and Horton, J.C., The circuitry of V1 and V2: Integration of cor, form, and motion, Annual Review of Neuroscience, Volume 28© 2005, 303-326,by Annual Reviews vAvw.annualreviews.org)

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Figure 6.13 Blobs and Connections in V1 and V2 (2 of 2)

(b) Neurons located in CO blobs of V1 project to thin stripes in V2. Neurons in the lnterblob regions of V1 project to pale and thick stripes of V2.

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Extrastriate Cortex

Combining information for perception of objects and visual scenes

Structures

Regions V2 – V5

Specialized to respond to features

Arranged hierarchically

Pathways

Dorsal Stream

Ventral Stream

Specialized to respond to features such as orientation, movement, spatial frequency, retinal disparity, or cor

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Figure 6.15 Structures and Pathways of the Extrastriate Cortex

The dorsal stream terminates in the posterior parietal lobe and conveys “where” information. The ventral stream terminates in the inferior temporal lab and conveys “what” information.

Figure 6.15 page 164

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Figure 6.16 ON and OFF Ganglion Cells

This figure shows responses of ON and OFF ganglion cells to stimuli presented in the center or the surround of the receptive field.

Figure 6.16 page 166

Role of retinal ganglion cells in light / dark perception

On cells and Off cells (Hartline, 1938)

Stimulation of the center or surrounding fields had contrary effects:

ON cells - excited by light falling in the central field (center), inhibited by light falling in the surrounding field (surround),

OFF cells responded in the opposite manner.

ON/OFF ganglion cells were briefly excited when light was turned on or off.

In primates most of these ON/OFF cells project mainly to the superior colliculus, involved in visual reflexes in response to moving or suddenly-appearing stimuli

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Figure 6.17 Enhancement of Contrast

(a) Although each gray square is of uniform darkness, the right edge of each square looks somewhat lighter, and the left edge looks somewhat darker. This effect appears to be caused by the opponent center surround arrangement of the receptive fields of the retinal ganglion cells. (b) This figure shows a schematic explanation of the phenomenon shown in panel a. Only ON cells are shown; OFF cells are responsible for the darker appearance of the left side of the darker square. We see the centers and surrounds of the receptive fields of several ganglion cells. (In reality these receptive fields would be overlapping, but the simplified arrangement is easier to understand. This example also includes only ON cells—again, for the sake of simplicity.) The image of the transition between lighter and darker regions falls across some of these receptive fields. The cells whose centers are located in the brighter region but whose surrounds are located at least partially in the darker region will have the highest rate of firing

Figure 6.17 page 167

The center-surround organization of retinal ganglion cell receptive fields enhances ability to detect the outlines of objects even when contrast is w

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Role of the Retina in Color Perception (1 of 2)

Trichromatic Coding

Protanopia (pro tan owe pee a)

Deuteranopia (dew ter an owe pee a)

Tritanopia (try tan owe pee a)

Physiogical investigations of retinal photoreceptors in higher primates have found that Young was right: Three different types of photoreceptors (three different types of cones) are responsible for cor vision.

Investigators have studied the absorption characteristics of individual photoreceptors, determining the amount of light of different wavelengths that is absorbed by the photopigments.

These characteristics are controlled by the particular opsin a photoreceptor contains; different opsins absorb particular wavelengths more readily.

Figure 6.17 shows the absorption characteristics of the four types of photoreceptors in the human retina: rods and the three types of cones.

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Role of the Retina in Color Perception (2 of 2)

Young was right!

Three different types of photoreceptors (cones) for color vision

Absorption characteristics of individual photoreceptors determine amount of light of different wavelengths absorbed

Characteristics controlled by particular opsin photoreceptor

Protanopia (pro tan owe pee a)

Inherited form of defective cor vision in which red and green hues are confused; “red” cones are filled with “green” cone opsin

Deuteranopia (dew ter an owe pee a)

Inherited form of defective cor vision in which red and green hues are confused; “green” cones are filled with “red” cone opsin

Tritanopia (try tan owe pee a)

Inherited form of defective cor vision in which hues with short

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Figure 6.18 Absorbance of Light by Rods and Cones

The graph shows the relative absorbance of light of various wavelengths by rods and the three types of cones in the human retina.

Figure 6.18 shows the absorption characteristics of the four types of photoreceptors in the human retina: rods and the three types of cones.

Figure 6.18, page 168

(Based on data from Dartnall et al., 1983.)

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Figure 6.19 Testing for Color Vision

Special images are used to assess protanopia, deuteranopia, and tritanopia. The tester shows the individual the images and asks them to identify the number in the circle. In protanopia, people have difficulty seeing the color red because their "red" cones are filled with "green" cone opsin. In deuteranopia, people have difficulty seeing green because their "green" cones appear to be filled with "red" cone opsin. In tritanopia, people have difficulty seeing blue because their retinas lack "blue" cones.

Figure 6.19 page 168

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Retinal Ganglion Cells: Opponent-Process Coding

Three-color code gets translated into opponent-color system at retinal ganglion cell

Neurons respond to pairs of primary colors, with red opposing green and blue opposing yellow

Retina contains two kinds of color-sensitive ganglion cells: red-green and yellow-blue

At the level of retinal ganglion cell, three-cor code gets translated into opponent-cor system

Daw (1968) and Gouras (1968) found that these neurons respond specifically to pairs of primary cors, with red opposing green and blue opposing yelw

Thus, the retina contains two kinds of cor-sensitive ganglion cells: red-green and yelw-blue

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Figure 6.20 Receptive Fields of Color-Sensitive Ganglion Cells

When a portion of the receptive field is illuminated with the color shown, the cell’s rate of firing increases. When a portion is illuminated with the complementary color, the cell’s rate of firing decreases.

Figure 6.20, page 179

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Figure 6.21 Color Coding in the Retina

a) Red light stimulating a “red” cone, which causes excitation of a red-green ganglion cell. (b) Green light stimulating a “green” cone, which causes inhibition of a red-green ganglion cell. (c) Yellow light stimulating “red” and “green” cones equally but not affecting “blue” cones. The stimulation of “red” and “green” cones causes excitation of a yellow-blue ganglion cell. (d) Blue light stimulating a “blue” cone, which causes inhibition of a yellow-blue ganglion cell. The arrows labeled E and I represent neural circuitry within the retina that translates excitation of a cone into excitation or inhibition of a ganglion cell. For clarity, only some of the circuits are shown.

Figure 6.21 page 169

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Figure 6.22 A Negative Afterimage

Stare for approximately 30 seconds at the plus sign in the center of the left figure; then quickly transfer your gaze to the plus sign in the center of the right figure. You will see colors that are complementary to the originals.

Figure 6.22 page 170

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Table 6.2 Properties of the Magnocellular, Parvocellular, and Koniocellular Divisions of the Visual System

Property	Magnocelluler Division	Parvocellular Division	Koniocellular Division
Color	No	Yes (from 'red' and 'green cones)	Yes (from “blue” cones)
Sensitivity to contrast	High	Low	Low
Spatial resolution (ability to detect fine detail)	Low	High	Low
Temporal resolution	Font (transient response)	Slow (sustained response)	Slow (sustained response)

Table 6.2 page 171

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Figure 6.23 Color Processing via Parvocellular and Koniocellular Systems

Figure 6.23 page 171

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Role of Extrastriate Cortex

Studies with Humans

Hadjikhani et al. (1998)

fMRI study

Color-sensitive region called area V8

Bouvier and Engel (2006)

92 cases of achromatopsia confirmed damage to V8 region

Study found a cor-sensitive region that included the lingual and fusiform gyri, in a cation corresponding to area TEO in the monkey’s cortex, which they called area V8

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Figure 6.24 Case of Damage to the Extrastriate Cortex that Resulted in Loss of Form, but Not Color, Perception

Patient P. B. experienced damage to the extrastriate cortex. Structural and functional MRI data from the patient P. B. show activation in area V1 (white areas on the MRI scans) when correctly identifying colors, though he could not perceive the form or shape of the stimulus.

Figure 6.24 page 172

Source: (Zeki et al., 1999)

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Perception of Form

Visual information analysis begins with neurons in striate cortex that are sensitive to orientation and spatial frequency

These neurons send information to area V2 and then to ventral stream of extrastriate cortex

The analysis of visual information that leads to the perception of form begins with neurons in the striate cortex that are sensitive to orientation and spatial frequency.

These neurons send information to area V2 and then on to the subregions of the visual association cortex that constitute the ventral stream.

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Figure 6.25 Spatial Frequency

This figure compares two kinds of gratings: (a) Square-wave grating, and (b) sine-wave grating. (c) Angles are drawn between the sine waves, with the apex at the viewer’s eye. The visual angle between adjacent sine waves is smaller when the waves are closer together.

Figure 6.25 page 174

Hubel and Wiesel:

Neurons of striate cortex respond most strongly to sine-wave gratings

sine-wave grating oks like a series of fuzzy, unfocused parallel bars. Ang any line perpendicular to the ng axis of the grating, the brightness varies according to a sine-wave function

spatial frequency of a sine-wave grating is its variation in brightness measured in cycles per degree of visual angle

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Figure 6.26 Spatial Filtering

The two pictures contain the same amount of low-frequency information, but extraneous high-frequency information has been filtered from the picture on the right. If you ok at the pictures from across the room, they ok identical.

Figure 6.26 page 175

Frequency impacts perception:

thus, the most important visual information is that contained in w spatial frequencies.

When w-frequency information is removed, the shapes of images are very difficult to perceive.

(From Harmon, L. D., and Julesz, B., Masking in visual recognition: Effects of two-dimensional filtered noise, Science, 1973, 180, 1191–1197. Copyright 1973 by the American Association for the Advancement of Science. Reprinted with permission.)

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Perception of Form: Role of the Extrastriate Cortex

Studies with laboratory animals

Inferior temporal cortex

Recognition of visual patterns

Identification of objects

Posterior area (TEO)

Anterior area (TE)

The fact that neurons in the primate inferior temporal cortex respond to very specific complex shapes suggests that the devepment of the circuits responsible for detecting them must involve learning

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Figure 6.27 Category-Selective Regions in Monkeys and Humans

Views of the temporal lobes of monkeys E and J as well as the grouped human dataset showing category-selective regions throughout the brain. Voxels are cored according to their preference for one of the four categories tested.

Figure 6.27 page 176

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Perception of Form: Role of the Extrastriate Cortex

Studies with Humans

Visual Agnosia (ag no zha)

Lateral Occipital Complex (C)

Prosopagnosia

Fusiform Face Area (FFA)

Extrastriate body area (EBA)

Parahippocampal Place Area (PPA)

Visual Agnosia (ag no zha)

Deficits in visual perception in absence of blindness; caused by brain damage

Lateral Occipital Complex (C)

Region of extrastriate cortex; involved in perception of objects other than people’s bodies and faces

Prosopagnosia (prah soh pag no zha)

Failure to recognize particular people by sight of their faces

Fusiform Face Area (FFA)

Region of visual association cortex cated in inferior temporal; involved in perception of faces and other complex objects that require expertise to recognize

Parahippocampal Place Area (PPA)

Region of limbic cortex on medial temporal be involved in perception of particular places (“scenes”)

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Figure 6.29 Perception of Faces and Bodies

The fusiform face area (FFA) and extrastriate body area (EBA) were activated by images of faces, headless bodies, body parts, and assorted objects.

Figure 6.29 page 177

(Adapted from Schwarzse, R. F., Baker, C. I., and Kanwisher, N., Separate face and body selectivity on the fusiform gyrus, Journal of Neuroscience, 2005, 23, 11055–11059.)

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Figure 6.30 The Parahippocampal Place Area

The scans show activation of the parahippocampal cortex in Patient D. F., a woman with a profound visual agnosia for objects, in response to viewing scenes (a) and similar responses in a control subject (b).

Figure 6.30 page 179

(From Steeves, J. K. E., Humphrey, G. K., Culham, J. C., et al., Behavioral and neuroimaging evidence for a contribution of cor and texture information to scene classification in a patient with visual form agnosia, Journal of Cognitive Neuroscience, 2004, 16, 955–965. Reprinted by permission.)

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Developmental Aspects of Recognition

Is there a developmental difference in the way children and adults respond to faces?

Basic ways individual faces are recognized

differences in features

differences in contour

differences in configuration of features

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Figure 6.31 Fusiform Gyrus Responses to Faces

This “inflated” ventral view of the brain of an 8-year-old child and an adult from the study by Golarai et al., (2007) shows the regions of the fusiform gyrus that responded to the sight of faces. The FFA is much larger in adults.

You can see the age-related size difference and also the difference between the size of this region in the left and right hemispheres.

Figure 6.31, page 179, shows regions on left and right fusiform cortex of an eight-year-old child and an adult.

(Courtesy of Golijeh Golarai, Department of Psychogy, Stanford University.)

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Perception of Spatial location: Role of the Retina

Retinal Disparity

Binocular vision

Provides vivid perception of depth through process of stereoscopic vision or stereopsis

Depth perceived by many means, most of which involve cues that can be detected by monocularly

Contributions to depth perception

Perspective

Relative retinal size

loss of detail through the effects of atmospheric haze

Relative apparent movement of retinal images with head movement

We perceive depth by many means, most of which involve cues that can be detected monocularly, that is, by one eye alone.

For example, perspective, relative retinal size, loss of detail through the effects of atmospheric haze, and relative apparent movement of retinal images as we move our heads all contribute to depth perception and do not require binocular vision.

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Perception of Orientation and Movement

Role of the striate cortex

Hubel and Wiesel demonstrated orientation sensitivity

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Figure 6.35 Orientation Sensitivity

An orientation-sensitive neuron in the striate cortex will become active only when a line of a particular orientation appears within its receptive field. For example, the neuron depicted in this figure responds best to a bar that is vertically oriented.

Figure 6.35 page 183

(Adapted from Hubel, D. H., and Wiesel, T. N., Receptive fields of single neurones in the cat’s striate cortex, Journal of Physiogy [ndon], 1959, 148, 574–591.)

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Perception of Orientation and Movement: Role of the Extrastriate Cortex

Optic Flow

Complex motion of points in visual field

Caused by relative movement between observer and environment

Provides information about relative distance of objects from observer and of relative direction of movement

Akinetopsia

Inability to perceive movement

Caused by damage to area V5 (MST) of visual association cortex

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Figure 6.36 The Location of Visual Area V5

Figure 6.36 page 184

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Figure 6.37 Responses to Viewing Form from Motion

This figure shows horizontal and lateral views of neural activity that occurred while the subject was viewing videos of biological motion. Maximum activity is seen in a small region on the ventral bank of the posterior end of the superior temporal sulcus, primarily in the right hemisphere.

Figure 6.37 page 185

(Based on Grossman, E. D., and Blake, R., Brain activity evoked by inverted and imagined biogical motion, Vision Research, 2001, 41, 1475–1482.)

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Perception of Orientation and Movement: Form from Motion

Grossman et al. (2000)

Video showing form from motion activated small region on ventral bank of posterior end of the superior temporal sulcus

More activity was seen in the right hemisphere despite visual field presentation

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Table 6.3 Regions of the Human Visual Cortex and Their Functions (1 of 3)

Region of Human Visual Cortex	Name of Region (If Different)	Function
V1	Striate cortex	Small modules that analyze orientation, movement, spatial frequency, retinal disparity, and color
V2	No data	Further analysis of information from V1
Ventral Stream	No data	No data
V3+VP	No data	Further analysis of information from V2
V3A	No data	Processing of visual information across entire visual field of contralateral eye
V4d/V4v	V4 dorsal/ventral	Analysis of form; processing of cor constancy; V4d = lower visual field, V4v = upper visual field

Table 6.3 page 186 - 187

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Table 6.3 Regions of the Human Visual Cortex and Their Functions (2 of 3)

Region of Human Visual Cortex	Name of Region (If Different)	Function
V8	No data	Color perception
LO	Lateral occipital complex	Object recognition
FFA	Fusiform face area	Face recognition, object recognition by experts (“flexible fusiform area”)
PPA	Parahippocampal place area	Recognition of particular places
EBA	Extrastriate body area	Perception of body parts other than face
Dorsal Stream	No data	No data
V7	No data	Visual attention; control of eye movements

Table 6.3 page 186 - 187

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Table 6.3 Regions of the Human Visual Cortex and Their Functions (3 of 3)

Region of Human Visual Cortex	Name of Region (If Different)	Function
MT/MST	Medial temporal/medial superior temporal (named for cations in monkey brain)	Perception of motion; perception of biological motion and optic flow in specific subregions
LIP	Lateral intraparietal area	Visual attention; control of saccadic eye movements
VIP	Ventral intraparietal area	Control of visual attention to particular cations; control of eye movements; visual control of pointing
AIP	Anterior intraparietal area	Visual control of hand movements: grasping, manipulation
MIP	Middle intraparietal area; parietal reach region (monkeys)	Visual control of reaching
CIP	Caudal intraparietal area; caudal parietal disparity region	Perception of depth from stereopsis

Table 6.3 page 186 - 187

Psychology Assignment 3

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