6.2.1 How The Brain Processes Visual Information 2 Flashcards Preview

175.205 Brain and Behaviour > 6.2.1 How The Brain Processes Visual Information 2 > Flashcards

Flashcards in 6.2.1 How The Brain Processes Visual Information 2 Deck (20):
1

To find a ____ receptive field, an investigator records from the cell while shinning light in various locations. If the light from a particular spot excited the neuron, then that location is part of the neurons excitory receptive field. If it inhibits activity, the location is in the inhibitory receptive field.

cells

2

Primate ganglion cells for into ____ categories: parvocellular, magnocellular, and koniocellular.

three

3

____ neurons, with small cell bodies and small receptive fields, are mostly in or near the fovea.

Parvocellular

4

The ____ neurons, with larger cell bodies and receptive fields, are distributed evenly throughout the retina.

magnocellular

5

The ____ neurons have small cell bodies, similar to the parvocellular neurons, but they occur throughout the retina.

koniocellular

6

Parvocellular neurons, with their small receptor fields, are well suited to detect ____ ____. They also respond to colour, each neuron being excited by some wavelengths and inhibited by others.

visual details

7

Magnocellular neurons are found throughout the retina, including the periphery, where we are sensitive to ____ but not colour or details.

movement

8

Koniocellular neurons have ____ functions, and their axons terminate in several locations.

several

9

Exons from the ganglion cells form the optic nerve, which proceeds to the optic chasm, where half of the axons cross to the ____ hemisphere.

opposite

10

Most of the axons in the optic nerve go to the ____ ____ nucleus of the thalamus. Cells of the lateral geniculate have receptive fields that resemble those of the ganglion cells – excitatory or inhibitory central portion and a surrounding ring with the opposite effect.

lateral geniculate

11

Most visual information from the lateral geniculate nucleus of the thalamus goes to the ____ ____ ____ in the occipital cortex, aka area V1 or the striate cortex because of its striped appearance.

primary visual cortex

12

People with damage to the ____ report no conscious vision, no visual imagery, and no visual images in their dreams.

area V1

13

Adults who lose vision because of eye ____ continue to have visual imagery and visual dreams.

damage

14

Some people damage to the area V1 show a surprising phenomenon called ____, the ability to respond in limited ways to visual information without perceiving it consciously.

blindsight

15

Some blindsight patients can reach for an object they cannot see, avoiding obstacles in the way. Some can identify an objects colour, direction of movement, and approximate shape, again while insisting that they are just ____.

guessing

16

The research supports two explanations for these puzzling contradictions: first, in many cases, small islands of ____ ____ remain within an otherwise damaged visual cortex, not large enough to provide conscious perception but enough to support limited visual functions.

healthy tissue

17

The second explanation is, the thalamus sends visual input to several other brain areas besides V1, including parts of the ____ ____. After V1 damage, the connections to these other areas strengthen enough to produce certain kinds experience despite a lack of conscious visual perception.

temporal cortex

18

Impairing the input from the thalamus to other cortical areas ____ blindsight.

abolishes

19

Hubble and Wiesel distinguished several types of cells in the visual cortex. A ____ ____ has a receptive field with fixed excitatory and inhibitory zones.

simple cell

20

Most simple cells have bar-shaped or edge-shaped receptive fields. More of them respond to ____ or ____ orientations than to diagonals.

horizontal or vertical

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