Chapter 10 Flashcards
What is population receptive field modelling?
The measuring of a neuronal population encodes visual stimuli
What are two factors which contribute to a larger population receptive field size?
- contains neurons with large receptive fields
- contains neurons with small receptive fields, across different locations
The field of view of V1 spans _____ because _____
- the whole visual field
- anywhere you can see requires a V1 representation
How does multisensory integration enhance performance?
- increased salience leads to faster and more accurate detection
- more robust and precise detection leads to improved discrimination and estimation
What is the population receptive field method useful for?`
Quantifying how a neuronal population encodes visual information distributed over space and time
What is a pRF?
The set of locations in the visual field that, when occupied by a contrast pattern, produce a BOLD response
How does the pRF model go beyond previous measurement methods?
pRF specifies the spatial extent, not just the peak location, that produces a BOLD response
With respect to multisensory perception, the observer needs to solve which computational challenges?
- 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
What is the forced-fusion model?
The model assumes that the audio and visual inputs from an audiovisual stimulus come from the same source
In the forced-fusion model, the reliability of an audiovisual estimate is equal to _____
the sum of all its unisensory reliabilities
Studies suggest that higher-order association areas integrate signals from ____ and ____, weighted by their _____ into representations of _____
- vision
- touch
- reliabilities
- shapes
What does the Bayesian inference model do?
Models the potential causal structures - both if inputs had a common cause or were separate
Studies show that human observers integrate or segregate multisensory information with the principles of _______
Bayesian causal inference
The brain establishes Bayesian causal inference by _____
encoding multiple spacial estimates across a hierarchy - segregation at the bottom, forced fusion in the middle, and uncertainty at the top
Entering the retina, visual information first reaches the _______
primary visual cortex
What are artificial neural networks?
A class of models that learn to recognize patterns from input data
What is the back-propagation algorithm?
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
What is a CNN?
An artificial neural network made up of multiple layers, each implementing signal- and visual-processing functions
What are three functions of prediction error for Bayesian speech perception?
- 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
Is a predictive coding system (for speech) top-down or bottom-up?
top-down
In predictive coding, top-down predictions act to supress ______
bottom-up prediction error signals at lower hierarchical levels
When we perceive things, the brain is _____ a real-world picture
reconstructing
How many neurons are in a cubic mm in the cortex?
20,000-40,000
How large is a voxel?
1.6mm^3
What do fMRI field potentials sum?
The activity of all neurons in a voxel
