Neural Representations

Question 1

A rapid change in the voltage of the cell membrane

Answer 1

Action potential

Question 2

The limited region of space to which visually sensitive cells respond

Answer 2

Receptive field

Question 3

About how many neurons in the visual cortex are involved in the representation of a single image

Answer 3

At least 200 million

Question 4

Records changes in metabolic activity in order to produce a functional view of the brain. Allows simultaneous detection of entire neuronal population reacting to each stimulus - can estimate number of neurons involved

Answer 4

fMRI

Question 5

What is the feature detection theory?

Answer 5

Different cells detect different features, then put it all together to form an image

Question 6

What is the multiple spatial channels theory?

Answer 6

The world is broken up into high and low frequencies, and cells analyze their specialty

Question 7

The name “grandmother cells” are associated with which theory?

Answer 7

Feature detection theory! Idea that certain cells respond to not only images of a specific person’s face, but also to concepts of them (cells devoted to specific things)

Question 8

What is the binding problem?

Answer 8

Figuring out how the brain integrates components to a percept and links features to one object

Question 9

2 potential answers to the binding problem:

Answer 9

1. Convergent hierarchical coding (A.K.A. grandmother cells)
2. Temporal binding: synchronized timing of firing links together cells into cell assemblies that represent parts of an object

Question 10

What do on-centre, off-surround geniculate cells respond best to?

Answer 10

Spots

Question 11

Which two kinds of cells are in the primary visual cortex and what are their characteristics?

Answer 11

Simple cells: have an on/off region, monocular OR binocular, respond best to bars
Complex cells: no on/off region, mostly binocular

Question 12

What is “looming”?

Answer 12

The sudden expansion of objects as you get close (can’t detect it until you get REAL close)

Question 13

What is “motion camouflage”?

Answer 13

When you move so you appear to be staying in the same spot in the background (appear as just part of the background)

Question 14

What happens if the cells that detect motion are damaged?

Answer 14

The world is perceived in a series of still pictures

Question 15

Which action is difficult for grandmother cells to accomplish?

Answer 15

Invariance: encoding representations regardless of size, angle, etc.