regions of the brain and brain plasticity Flashcards
what is brain lateralisation? Sperry
behavioural functions controlled by specific regions of the brain
-language lateralised to left hemisphere
what are the two background studies for sperry?
-Brocca:
carried post mortems on ppl who had speech production problems but understood language= damage to lower left frontal lobe
-Wernicke:
those with severe deficit in understanding speech, left temporal lobe
what is the split brain background for sperry?
-undergone commissurotomy on corpus collosum ‘cure for epilepsy’ prevent spreading
-epilepsy= excessive signalling of nerves
what is the aim for sperry?
-test hemisphere de-connection in humans
.if memory perception differs between hemispheres
.extent hemispheres would interact to achieve memory and perception
what was the method for sperry?
lab setting
quasi
repeated measures
iv- split brain
dv- ability to perform variety of visual and tactile tasks
what was the sample for sperry?
11 epileptic patients
mix of ages and sexes
length between operation and study vary (largest 5.5years)
what was the visual test?
-covered eye, fix point
-visual stimuli on 35 mm transparencies for 1/10 of a second on translucent screen
what was the tactile test?
object placed in hands
left hand processed by right hemisphere
what were the apparatus for sperry?
translucent screen
tachnistoscope
what were the visual results for sperry?
-info in one visual feed only recognised in same field
-info to rvf could be described in speech and writing
-if same info presented to lvf claimed didn’t see anything or flash of light
-could point left hand to matching picture
what were the tactile results for sperry?
-objects in right hand described in speech and writing
-same objects in left hand make wild guesses
-felt by one hand recognised by same hand
-two objects placed in each hand both hands selected own object
what were the conclusion for sperry?
-language lateralised in left hemisphere
-split brain lack integration
-split brain 2 independent streams if consciousness, own memories, perceptions, impulses
-not impaired, perform better than normal
background for casey?
-use cog control to delay gratification.
-cooling-direct attention away from hot feature and focus on cool
background- mischel
-Mischel et al- cool and hot thoughts involve own neurocognitive system, cool= prefrontal cortex, hot= limbic system
-marshmallow test- 1/3 resisted
sperry background-Eigsti
performance in childhood predicts performance in adulthood
what was caseys aim?
to investigate if delay of gratification in childhood accurately predicts impulse control when adults (40)
what were the variables for Casey?
Iv- if P was high or low delayer
Dv- performance on experiment 1 (reaction times and accuracy) and imaging results in experiment 2
What was casey’s method?
repeated measures
longitudinal study 4-40
What was Casey’s sample?
562 4year olds Stanfords Bing nursery school, completed delay of gratification test
1) 59 (23 male and 36 female) 32 high and 27 low
2) 27 (13 male 14 female) 15 high and 11 low
one man excluded so 26
What was Casey’s experiment 1?
-own homes through pre programmed computers
-cool= presented m+f neutral face one sex was Go and other No Go
-hot= m+f happy expressions
-told to respond asap
-faces appeared 1/2 seconds and followed by 1 second interval
-160 faces in total
what was Casey’s experiment 2?
26 scanned by fMRI whilst completing hot version of go/no go task
-only 48 faces shown
-each face shown for 1/2 second followed by 2-14.5 second interval
what were the results for Casey 1?
both groups were highly accurate
high- 99.8%
low-99.5%
low delayers less accurate in no good way trials
what were results for Casey 2?
-right frontal gyrus less active in low delayers
-higher activity in ventral striatum in low delayers
what were Casey conclusions?
-sensitivity to environmental hot cues plays significant role in an individuals ability to suppress actions to alluring cues
-nature: individuals who struggle delaying gratification at 4 carry this into adulthood