Chapter 10

Question 1

What is population receptive field modelling?

Answer 1

The measuring of a neuronal population encodes visual stimuli

Question 2

What are two factors which contribute to a larger population receptive field size?

Answer 2

• contains neurons with large receptive fields

- contains neurons with small receptive fields, across different locations

Question 3

The field of view of V1 spans _____ because _____

Answer 3

• the whole visual field

- anywhere you can see requires a V1 representation

Question 4

How does multisensory integration enhance performance?

Answer 4

• increased salience leads to faster and more accurate detection
• more robust and precise detection leads to improved discrimination and estimation

Question 5

What is the population receptive field method useful for?`

Answer 5

Quantifying how a neuronal population encodes visual information distributed over space and time

Question 6

What is a pRF?

Answer 6

The set of locations in the visual field that, when occupied by a contrast pattern, produce a BOLD response

Question 7

How does the pRF model go beyond previous measurement methods?

Answer 7

pRF specifies the spatial extent, not just the peak location, that produces a BOLD response

Question 8

With respect to multisensory perception, the observer needs to solve which computational challenges?

Answer 8

• Deciding whether signals originate from a common cause and should be integrated
• Integrating signals from a common cause along with prior knowledge, with emphasis on more reliable information

Question 9

What is the forced-fusion model?

Answer 9

The model assumes that the audio and visual inputs from an audiovisual stimulus come from the same source

Question 10

In the forced-fusion model, the reliability of an audiovisual estimate is equal to _____

Answer 10

the sum of all its unisensory reliabilities

Question 11

Studies suggest that higher-order association areas integrate signals from ____ and ____, weighted by their _____ into representations of _____

Answer 11

• vision
• touch
• reliabilities
• shapes

Question 12

What does the Bayesian inference model do?

Answer 12

Models the potential causal structures - both if inputs had a common cause or were separate

Question 13

Studies show that human observers integrate or segregate multisensory information with the principles of _______

Answer 13

Bayesian causal inference

Question 14

The brain establishes Bayesian causal inference by _____

Answer 14

encoding multiple spacial estimates across a hierarchy - segregation at the bottom, forced fusion in the middle, and uncertainty at the top

Question 15

Entering the retina, visual information first reaches the _______

Answer 15

primary visual cortex

Question 16

What are artificial neural networks?

Answer 16

A class of models that learn to recognize patterns from input data

Question 17

What is the back-propagation algorithm?

Answer 17

An artificial neural network’s error is calculated by comparing its output to the desired result, then iteratively calculating the error value for each layer in order to update the network

Question 18

What is a CNN?

Answer 18

An artificial neural network made up of multiple layers, each implementing signal- and visual-processing functions

Question 19

What are three functions of prediction error for Bayesian speech perception?

Answer 19

• combining prior knowledge and degraded speech for optimal word identification
• supporting rapid learning processes
• ensuring listeners are able to learn new words over the lifespan

Question 20

Is a predictive coding system (for speech) top-down or bottom-up?

Answer 20

top-down

Question 21

In predictive coding, top-down predictions act to supress ______

Answer 21

bottom-up prediction error signals at lower hierarchical levels

Question 22

When we perceive things, the brain is _____ a real-world picture

Answer 22

reconstructing

Question 23

How many neurons are in a cubic mm in the cortex?

Answer 23

20,000-40,000

Question 24

How large is a voxel?

Answer 24

1.6mm^3

Question 25

What do fMRI field potentials sum?

Answer 25

The activity of all neurons in a voxel