The Neural Code

Question 1

What is the neural code?

Answer 1

How neurones get signal where information is encoded for communication

Question 2

What are local brain networks?

Answer 2

Small generic processing units

Question 3

What are global brain networks?

Answer 3

Relating in processes in unit dedicated to specific brain regions

Question 4

How is encoding in the brain important?

Answer 4

For extraction of categories and finding the identity of objects and our environment

Question 5

How do we identify objects?

Answer 5

With filtering to identify properties

Question 6

How do we classify an object?

Answer 6

Measuring the amount with intensity and frequency

Question 7

How do we adjust the precision of object classification?

Answer 7

Fine tunnign

Question 8

What is a managing capacity?

Answer 8

Compression of information into small compartments for high effectiveness

Question 9

How can a neural response be measured?

Answer 9

As a graded change in electrical potential and a change in membrane voltage which can determine excitation or inhibition

Question 10

What is a neural response?

Answer 10

Encoding in the number of action potentials

Question 11

What is the rate code?

Answer 11

The quantity of seconds information is encoded in the firing rate of action potentials

Question 12

How can neurones compute?

Answer 12

Through summation, direct representation of each sampling point or lateral inhibition

Question 13

What is direct representation of each sampling point?

Answer 13

One to one, where the size is not coded and there is low sensitivity but a high resolution

Question 14

What is summation?

Answer 14

The neural computation that results in adding together the responses of neurons (many to one)

Question 15

How do neurones interact in summation?

Answer 15

Through convergence

Question 16

What is convergence?

Answer 16

A graded response where the information from other sensors are combined

Question 17

What is lateral inhibition?

Answer 17

A neural computation in which responses from neighbouring regions are subtracted

Question 18

What does the graded response in lateral inhibition cause?

Answer 18

An optimum size for maximum activation

Question 19

What is a receptive field?

Answer 19

The location in space where the presence of a stimulus can produce a change in the response of a neurone

Question 20

What is a visual receptive field?

Answer 20

The location in space where the presence of a visual stimulus can produce a change in the response of a neurone

Question 21

What is a two dimensional receptive field?

Answer 21

When there is neural computation in two dimensions, in a receptive field light is collected from a restricted region of the visual field

Question 22

What is the response in 2D receptive fields?

Answer 22

The balancing of excitation from the centre and inhibition from the surrond receptive field

Question 23

What is spatial integration?

Answer 23

The adding of excitation and inhibition

Question 24

Why is there opponency in spatial integration?

Answer 24

There are photons from neighbouring regions which are balanced against each other

Question 25

What does contrast mean?

Answer 25

A relative difference in stimulus intensity between a bright and dark region of a visual stimulus

Question 26

What happens in regions of equal luminance?

Answer 26

Excitation and inhibition will cancel each other out

Question 27

What occurs at a luminance boundary?

Answer 27

Excitation and inhibition is not balanced so there is an increased difference of the perceived brightness where opponency will enhance the perceived contrast

Question 28

What is filtering?

Answer 28

The process in which signals are transmitted from regions around boundaries, but not from uniform areasW

Question 29

What do the filters do in neural networks?

Answer 29

Transform and compress information

Question 30

What are receptive fields functions?

Answer 30

Contrast enhancement, redundancy reduction and spatial filtering

Question 31

Small excitations and small inhibition?

Answer 31

Small response

Question 32

Large excitation and small inhibition?

Answer 32

Large response

Question 33

Large excitation and large inhibition?

Answer 33

Small response

Question 34

What does the size of the receptive field determine?

Answer 34

Spatial detail

Question 35

What is spatial frequency?

Answer 35

The number of cycles of a periodic pattern per degree of visual angle

Question 36

What are spatial frequency channels?

Answer 36

Parallel sets of receptive fields with different sizes

Question 37

How is feature specificity generated?

Answer 37

Parallel and hierarchial computations