biological area Flashcards
background to Sperry’s study
1940s commissurotomy was developed (split brain surgery) that cut the corpus callosum so that the abnormal electrical impulses could not spread throughout the brain
what is lateralisation of function
one side of the brain has a different role from the other
what is corpus callosum
fibres that carry the majority of information between the 2 hemispheres of the brain
what is contralateral control
each side of your body is controlled by the other side of your brain
aim of Sperry’s study
to study the functions of separated and independent hemispheres
sample and location of Sperry’s study
11 patients with epilepsy who had undergone commissurotomy
group of non-epileptics
procedure of Sperry’s study
visual tasks:
objects flashed to right/left visual field
right- say what they had seen
left- couldn’t say what they had seen but could point to object
nudes shown to left visual field- giggling, looks embarrassed but couldn’t say why
tactile tasks:
objects held by right/left hand
right- can say what they are holding
left- draw object but cannot say what they are holding
results from Sperry’s study
left hemisphere- has language ability and controls right side of your body
right hemisphere- can only communicate non verbally and say what they are holding
background to Blakemore and Cooper’s study
brain plasticity- your brain adapts and changes according to what you do in your life
they were inspired by work of Hirsch and Spinelli stating they could change the way neurons in the visual cortex aligned themselves by controlling what kittens could see as they grew up
what is visual cortex
part of the brain that receives and processes sensory nerve impulses from the eyes
what is startle response
the ‘backing off’ reaction of a cat when an object is moved quickly towards their face
what is visual placing
when a cat puts its feet out to meet the edge of a surface
aim of Blakemore and Coopers study
compare behavioural consequences of raising kittens seeing only horizontal or vertical stripes
investigate neurophysiological effect on neurons in kittens visual cortex
sample in Blakemore and Cooper’s study
2 kittens
from birth until 1 year old
procedure in Blakemore and Cooper’s study
first two weeks of kittens lives they were kept completely in the dark
kittens were put into a striped cylinder for 5 hours a day, they wore a black collar so they were only able to see vertical/horizontal stripes
when they were 5 months old they were taken into a well lit room with furniture to test their behaviour
results in Blakemore and Cooper’s study
behavioural- generally clumsy and no startle response or visual placing
neurophysiological- visual neurons within visual cortex had aligned themselves to match the environment the kittens were brought up in
background to Casey et Al’s study
the ability to delay gratification refers to the ability to resist a small reward now in favour of a greater reward in the future
Marshmallow test- children were told they could have one marshmallow now or two in 15 mins
sample of 4 year old children
aim to Casey’s study 1
wanted to find out whether people who had difficulties delaying gratification at the age of 4 would still have difficulties 40 years later
sample to Casey’s study 1
people who had taken part in Marshmallow test (59 people all age 44)
procedure to Casey’s study 1
participants were shown a series of faces, either happy or fearful, they had to press a button when they saw a particular expression on a person’s face
Go/no go task they had to hold back from pressing the button when they saw the happy faces
findings from Casey’s study 1
high delayers better at resisting pressing the go button when they saw the happy faces than low delayers
aim to Casey’s study 2
Casey wanted to see if there is a brain based explanation for the ability to delay gratification
sample to Casey’s study 2
of 59 from study 1, 27 decided to take part in 2nd study
procedure for Casey’s study 2
repeated go/no go task but inside a fMRI scanner
findings for Casey’s study 2
when low delayers saw the happy faces they had less activity in their inferior frontal gyrus (involved in regulating/controlling our behaviour)
background to Maguire’s study
hippocampus is a region of the brain that is involved in spatial memory, and hippocampal volumes can enlarge during seasons when demand for spatial ability is greatest suggesting it has plasticity IN ANIMALS
aim to Maguire’s study
wanted to find out whether the hippocampus might also show plasticity among humans
sample to Maguire’s study
16 right handed male London taxi drivers aged 32-62
had to learn the Knowledge
had been driving for at least 1 1/2 years since completing the Knowledge
procedure to Maguire’s study
drivers had MRI scan taken of their brains
these scans were compared to a control group of 50 people
the scans were analysed in 2 ways
pixel counting- 2nd measurement of area of hippocampus
voxel-based morphometry- 3d measurement of volume
findings from Maguire’s study
-more grey matter in posterior hippocampus in taxi drivers
procedure for correlational part of Maguire’s study
MRI scans subjected to further analysis as Maguire was interested in whether there was a correlation between length of time in years as a taxi driver and volume of grey matter in the hippocampus
findings for correlational part of Maguire’s study
positive correlation between length of time in years as a taxi driver and volume of grey matter in the posterior part of the hippocampus
how did Maguire use correlational method
investigated relationship between the amount of time spent as a taxi driver and the volume of grey matter in posterior hippocampus
