Binocular Vision: Lecture 17: Neuroanatomy and Neurophysiology of BV

Question 1

1. The LGN neuron inputs from each eye terminate in what Layer of the Striate cortex?
2. The First cells that LGN neurons synapse on are TOTALLY MONOCULAR and are segregated according to the Eye of Origin. At the next synapse after this, neurons from each eye BOTH CONVERGE to synapse on a SINGLE NEURON in the Layers where?
   a. The RESULT is what?
3. These Binocular Neurons are what kind of cells?
   a. About what % of Simple and Complex Cells Exhibit BINOCULAR RESPONSES?

Answer 1

1. Layer 4
2. Above and Below Layer 4
   a. the FIRST TRUE BINOCULAR CELLS in the VISUAL SYSTEM
3. Striate Cortical Simple Cells and Complex Cells
   a. 50%

Question 2

Binocular Facilitation and Summation

1. A Binocular Cell will do what to its Firing from a Baseline rate when what happens?
2. The Same Cell will similarly INCREASE its firing rate when the same stimulus is w/in what?
3. Binocular Cells Respond EVEN MORE VIGOROUSLY when what happens?
4. Binocular Response occurs when: The orientations of the stimuli presented to EACH eye MUST BE WHAT?
5. Although Binocular Cells respond to stimuli presented to both eyes, the STIMULI PRESENTED to EACH EYE MUST do what?

Answer 2

1. INCREASE; when an Appropriate Stimulus is w/in the Receptive Field of ONLY ONE EYE
2. w/in the Corresponding Receptive Field of the Other Eye
3. When Corresponding Receptive Fields of BOTH EYES are STIMULATED SIMULTANEOUSLY
4. IDENTICAL, and similar regions of Each Receptive Field must be STImULATED (eg…both must be ON REGIONS)
5. must MATCH in many of their properties

Question 3

Ocular Dominance Column

1. Cortical Cells with similar ORIENTATION PREFERENCES are what?
2. In Layer 4, Simple cells are still mostly monocular: They get input from what?
3. Cortical Cells are grouped in Slabs or Columns that run how?
   a. What are they called?
   b. If you insert an electrode into the Striate Cortex and Record a Cells response at Diff Depths, they are all DOMINATED by what?

Answer 3

1. are Grouped together
2. from one eye.
3. Perpendicular to the Cortical Surface
   a. OCULAR DOMINANCE COLUMNS (1/2 mm in width)
   b. by the Same Eye, Laterally, they could be from the other eye.

Question 4

Detection of Disparity

1. A Disparity-Selective Cell is called what?
2. Binocular Neurons in the Striate Cortex can detect what?
3. About half of the Binocular Simple and Complex Cells in VI also serve as what?
4. With increasing disparity, the binocular cell fires less and less until finally, at some particular prism strength, its firing rate reaches what?

Answer 4

1. a DISPARITY DETECTOR
2. DISPARITY
3. as DISPARITY DETECTORS
4. a MINIMUM

Question 5

Detection of Disparity

1. For each Receptive Field in one eye, there are many receptive fields in the other eye that interact with it. This is the NEUROPHYSIOLOGICAL version of what?
2. If we repeat Single Cell Recordings of Binocular Cells at Various Lateral Separation from the cell corresponding to the fixation point, we can produce a Neurophysiologically based what?
3. Disparity Adaptation is present and is seen in what?

Answer 5

1. of Panum’s Area
2. Horopter
3. in Disparity-tuned Cortical Neurons

Question 6

Detection of Disparity

1. Tuned Near (TN): Cells respond most strongly to targets located where?
2. Tuned Far (TF): cells are similar but respond to targets located on what?
3. Tuned Zero (To): cells respond most strongly to targets located where?
   a. Steinman refers to these as what?
   b. They’re inhibited by what?
4. Tuned Inhibitory (TI) neurons don’t fire when objects are near what?
   a. But they become active for objects that are what?

Answer 6

1. Slightly off but nearer than the horopter (900-1800’’ or 15-30 arc minutes of crossed disparity) and are INHIBITED w/targets located farther or nearer than this.
2. on the Opposite side of the horopter. They’re also inhibited by Targets LOCATED ELSEWHERE
3. very near the Horopter, having a disparity of less than 180’’ (3 arc minutes)
   a. as Tuned Excitatory Cells
   b. by Objects located elsewhere
4. the Fixation Point
   a. more than 180’’ off the horopter on either side

Question 7

1. Area V2 is retinotopically mapped, larger receptive fields, and contains cells with what?
   a. Up to what % of the Cells respond to DISPARITY?
2. Area V2: Association b/w what 2 areas?

Answer 7

1. With Binocular Response Properties
   a. 70%
2. B/w Stereoscopic Vision and Motion Processing

Question 8

From V1 (Received by V2)

1. Magno: (Thick Stripe Regions)
2. Parvo: (Interstripe Regions)
3. Parvo: (Thin Stripe Regions)

Answer 8

1. Low Spatial Frequency Disparity Detection, and Motion Processing = GROSS STEREOPSIS
2. High Spatial Frequency disparity detection and Chromatic Stimuli Processing = FINE STEREOPSIS
3. High Spatial Frequency disparity detection, and Luminance Level and Chromatic Stimuli Processing = FINE STEREOPSIS

Question 9

1. V2 Receives and also sends info back to what?
   a. It also TRANSMITS info to what areas?
2. Visual Area V3 Responds to WHAT?
   a. But not to what?
   b. Full functions of V3 are still unknown, although about HALF of the CELLS respond to what?
   c. Area V3 also Contains cells, which respond to what?

Answer 9

1. to V1
   a. to V3, V4, and V5/MT
2. to FIXED STEREOPSIS
   a. but not to changes in depth (i.e., not to motion-in-depth perception)
   b. to Disparity b/w Right and Left Perceptive Fields.
   c. ORIENTATION, and to PLANAR MOTION, which is MOTION ACROSS THE HOROPTER

Question 10

1. V4 has inputs from what area?
   a. Where are they situated?
   b. V4 Cells are TUNED for WHAT?
2. The Ventral Stream continues to what cortex?
   a. This area is tuned for what?

Answer 10

1. the Frontal Eye Movement Fields involved in Eye-movement control
   a. They’re situated in the Frontal Cortex
   b. SPATIAL FREQUENCY, ORIENTATION and COLOR, providing functions of SIMPLE SHAPE RECOGNITION, and V4 SHOWS PLASTICITY and RECEPTIVE FIELD CHANGES ASSOCIATED with ATTENTION
2. to the Inferior Temporal Cortex
   a. for Complicated Targets, like the Recognition of Faces

Question 11

1. V5: What area?
   a. Receives what?
   b. Signals here are USED for what?
   c. A Lesion here CREATES what?

Answer 11

1. Middle Temporal Cortex (located w/in the Dorsal Stream Only)
   a. Receives DIRECTLY SOME SIGNALS ORIGINATING from LAYERS 4B and 6 in VI, and originally from the EXTRA-FOVEAL (i.e. non-central) Visual Field
   b. for VELOCITY TUNING of V5/MT cells
   c. a SCOTOMA for MOTION

Question 12

1. Visual Area MST (middle superior temporal area) receives what?
   a. This area responds to what?
   b. It’s also sensitive to what?

Answer 12

1. INNERVATION from AREA V5/MT
   a. to the ROTATION of THREE-DIMENSIONAL TARGETS
   b. to Optic Flow, the Sensation of Movement through the environment (e.g., when traveling on a moving stairway)

Question 13

1. LOWER, or VENTRAL, STREAM has neurons that specifically respond to and help to analyze 3-D Binocular Disparity Input.
   a. So what is a MAJOR FUNCTION of the VENTRAL VISUAL PROCESSING STREAM?
   b. This Stream continues to what areas?
   c. The Ventral Stream is concerned with what 2 things?

Answer 13

1. a. RECOGNITION of 3-D SHAPES
   b. to Area V4 and to the Inferior Temporal Cortex
   c. with Object Representation and Also Visual Memory Storage

Question 14

1. The Upper, or dorsal stream passes from V1 to V2, to what?
   a. This pathway is related to what?
   b. Dorsal cells obtain input from broad adjacent and overlapping receptive fields in VI and process the analysis of what?
2. Although disparity-Detecting detecting binocular cells comprise about what % of cells in V1 and Increases to what % for area V2 Cells

Answer 14

1. To the Dorsomedial Area (including V3), to V5/MT and to the Posterior Parietal Region
   a. to the ANALYSIS of the LOCATION of OBJECTS, and with STEREOMOTION PERCEPTION (motion-in-depth), and with HAND-EYE COORDINATION and CONTROL, including SACCADIC EYE MOVEMENTS.
   b. of the Slant or Tilt of a Visual Surface
2. 50%; 70%