Lecture 17: Individual Differences in Motor Control Flashcards
general intelligence tests are more predictive of performance in phase
1
perceptual-speed (RT) abilities are more predictive in phase
2
psychomotor abilities are more predictive in phase
3
Shams et al: sound-induced flash illusion
-same flash with different corresponding sounds
-due to binding 1 event can be percieved as 2 because of audio
-determine temporal binding window
what is the temporal binding window
the amount of time for something to be multi-sensory rather than 2 separate events
when is visual information good?
to know where event takes place
when is auditory information good?
for judging when/time of event
does everyone have the same temporal binding window
no, variations between individuals, some may be too small to detect
what can we use to understand perceptual thresholds
behavioural methods; asking people when they percieve a task
How ould we determine the “perceptual threshold” for an individual? (lowst time to percieve appearance of 2 stimuli)
staircase method; present 2 stimuli @ varying intervals until the person perceives the 2 as one event
psychometric curve
-stimulus detection as a function if intensity/time
stimulus intenstity at threshold
the individual is 50% correct
psychometric curve to left
the stimulus is easier to detect (lower threshold)
psychometric curve to the right
the stimulus is more difficult to detect
Gaussian Distribution
probability of detecting stimulus over perceived intensity
3 parts of probability distribution for signal detection theory
- just noise
- Signal and noise
- Overlap - either belongs to signal or noise
if perceived intensity is greater than criterion
stimulus is detected
if percieved intensity is less than criterion
stimulus is undetected
Possible outcomes
- Hit (correct yes)
- False alarm (incorrect yes)
- Correct rejection (correct no)
- Miss (incorrect no)
Liberal criterion
hits> correct rejection ; hit a lot of signal but also hit a lot of noise
Conservative Criterion
Hits < Correct rejection ; miss a lot of signal but correctly reject just noise
d-prime
a measure of sensitivity and estimates the standardized difference between the mean of two distributions
d’=
Z(%HITS)-Z(% FAlse Alarms)
Stevenson et al 2012
-investigated if individual differences in ther perception of the McGurk Stimulus could be related to varability in the temporal binding window of participants
2 conditions of stevenson et al
AAV (auditory, left)
VAA (visual, right)
results from stevenson et al
-no relationship between perception of mcgurk effect and left (auditory) binding window
-individuals with short temporal binding window had higher likelihood of percieving the illusion
-right side of TBW was negatively correlated with likelihood of perception
Lebar et al 2015
examined brain responses to visual stimuli during mirror-reversed drawing task
*this is more difficult so people would have to rely more on visual info
findings of lebar et al
-didnt find any differences in brain response to visual stimuli in mirror reversed vs normal drawing
-high performers showed increased visual cortex activation during drawing when compared to low performers
how can we design an experiment to examine if high-performers really do show increased brain activity
between group study and training studies
hwo can individual differences be quantified
using signal detection theory
