Multisensory integration - cue combination

Question 1

tactile info when engaging/touching/manipulating an object =

Answer 1

haptic feedback

Question 2

different senses might provide conflicting information about a sensory stimulus =

Answer 2

sensory conflicts

Question 3

sensory conflicts need to be resolved. How?

Answer 3

we need to make a choice to resolve the conflict

Question 4

does vision or touch dominate judgement of object size?

Answer 4

vision dominates perceived object size

Question 5

what is it called when visual input dominates to provide a more accurate judgement of object size?

Answer 5

visual capture > this is the VISUAL CAPTURE EFFECT

Question 6

does touch have any influence on the visual capture effect?

Answer 6

yes but only small but consistent influence

Question 7

what were the 3 ways Rock and victor assessed visual capture?

Answer 7

pointing, feeling, drawing

Question 8

is there a strict sensory hierarchy?

Answer 8

no, audition can dominate vision

Question 9

who conducted a study to show that audition can dominate vision by testing for sensory conflict?

Answer 9

Shams et al, 2000

Question 10

what were the results from Shams et al, 2000 study?

Answer 10

number of auditory beeps determined the number of reported visual flashes, sound was followed more closely than sight e.g. 1 flash + 2 beeps = 2 beeps reported. SHOWS WE TRUST AUDITION MORE THAN VISUAL SENSE

Question 11

what is the modality precision hypothesis?

Answer 11

modality with highest precision and lowest uncertainty is chosen depending on the task type

Question 12

following the modality precision hypothesis > spatial task uses _____, temporal task uses ______

Answer 12

vision, audition

Question 13

what 3 things is sensory uncertainty due to?

Answer 13

perceptual limits, neural noise, cognitive resource limits

Question 14

communication between neurons at the synapse doesn’t work > leads to uncertainty. this is due to?

Answer 14

neural noise

Question 15

different senses have different levels of ______ uncertainty

Answer 15

noise

Question 16

how did Ernst and Banks (2002) shift ppts attention to different senses?

Answer 16

by manipulating the level of sensory uncertainty

Question 17

what does MLE stand for?

Answer 17

Maximum Likelihood Estimation

Question 18

what is a normative model?

Answer 18

optimal solution to how a problem should be solved

Question 19

what is a normative model based on?

Answer 19

theory

Question 20

what is a process model?

Answer 20

how a problem is actually solved

Question 21

what is a process model based on?

Answer 21

data

Question 22

how should we solve problem of sensory integration?

Answer 22

pick integration method that minimises sensory uncertainty > maximum likelihood estimator

Question 23

when making an estimate based on haptic and visual inputs what is the best way to get a maximum likelihood estimation?

Answer 23

combine senses and their uncertainty to get an INTEGRATED SIGNAL with the smallest possible combined uncertainty

Question 24

a large distribution means high ______ which means high sensory _______ and a lower _______

Answer 24

variance, uncertainty, probability

Question 25

a ______ distribution means low variance which means ___ sensory uncertainty and a _____ probability

Answer 25

small, low, higher

Question 26

different senses have different amounts of what?

Answer 26

sensory noise

Question 27

when there are 2 different sense inputs (visual and haptic) there are 2 distributions produced because of 2 different estimates. why are 2 estimates produced?

Answer 27

because sensory conflict is created

Question 28

how are 2 probabilities integrated if both estimates have the same amount of variance and uncertainty level?

Answer 28

place the integrated estimate exactly in the middle

Question 29

does a combined estimate of 2 sense inputs have lower or higher uncertainty?

Answer 29

lower! smaller variance = lower uncertainty > higher probability

Question 30

when integrating probabilities, if visual uncertainty is lower than haptic uncertainty what does theory suggest we should trust?

Answer 30

vision

Question 31

if visual uncertainty is smaller than haptic how are the estimates combined?

Answer 31

biased towards the visual estimate

Question 32

visual weight of 1 and haptic weight of 0 = only trust ____ input

Answer 32

visual

Question 33

visual weight of 0 and haptic weight of 1 = only trust _____ input

Answer 33

haptic

Question 34

according to MLE what can be calculated from the variance (sensory uncertainty) of the visual and haptic distribution?

Answer 34

optimal weights

Question 35

integrating info from multiple sources always causes uncertainty to _______

Answer 35

decrease (as variance is decreased when combining)

Question 36

combining variance leads to a ______ in variance (minimal variance)

Answer 36

decrease

Question 37

after converting sensory inputs from different senses into a coherent reference frame, info needs to be _______ and sensory conflicts need to be _______

Answer 37

integrated, resolved

Question 38

MLE is a ________ model that allows us to calculate the _______ way to integrate info

Answer 38

normative, optimal

Question 39

what is shown with perceived bar length when no visual noise is added? (Ernst & Banks, 2002)

Answer 39

biased towards visual input. shows visual dominance > visual capture (we trust visual over haptic input)

Question 40

what happens when we add visual noise? (Ernst & Banks, 2002)

Answer 40

perception of bar length moves more towards haptic estimate and becomes determined by both visual and haptic inputs

Question 41

explain why adding visual noise means theres a shift in our estimate towards haptic estimate

Answer 41

visual input is more noisy > we have more uncertainty and can't trust it > shift estimate towards haptic feedback as can't fully rely on visual

Question 42

what happens when even more (high) visual noise is added?

Answer 42

perception of bar length is determined by haptic inputs and we rely on haptic over visual

Question 43

as visual noise increases we move toward haptic capture as visual weight _______ and haptic weight ________

Answer 43

decreases, increases

Question 44

more visual noise = more ________ which means we can't trust its estimate

Answer 44

uncertainty

Question 45

do we always integrate info optimally?

Answer 45

idea that we don't integrate it optimally as heuristics aren't optimal (but still work well enough)

Question 46

is it easier to know the uncertainty for optimal integration in sensory perception or cognitive reasoning?

Answer 46

sensory perception! can generally estimate noise and uncertainty levels

Question 47

why is it hard we always calculate uncertainty levels in our brains?

Answer 47

calculations are intractable and take a long time

Question 48

what do we use instead of integrating info optimally and why?

Answer 48

use HEURISTICS! suboptimal but fast and provide good enough solutions

Question 49

we are good at estimating ______ noise but bad at estimating _______ noise

Answer 49

sensory, cognitive

Question 50

are probabilities encoded in the brain? discuss.

Answer 50

little direct electrophysiological evidence but several plausible theories > may be down to neurons to tell us the variance? different neurons may encode different probability values? different neurons may have different estimates? (active research area with lots of debate)