biological area year 2 Flashcards
what is brain plasticity?
the ability of the brain to modify its own structure and function
refers to the brain’s ability to recognise neural pathways throughout the lifespan as a result of experience
aim of blakemore and cooper?
to limit the visual experience of kittens to one orientation and to compare the behavioural consequences of this restricted visual environment on the kittens
to investigate the neuropsychological effects on the neurones in the kittens’ visual cortex
to investigate the responses of the kittens’ brain development to their environment and illustrate brain plasticity in their developing visual sense
sample of blakemore and cooper?
kittens, from birth to approximately one year old
procedure of blakemore and cooper?
from birth, kittens were housed in a completely dark room
from 2 weeks, the kittens were placed into a specially designed cylindrical apparatus, which was 46cm in diameter and 2m high
the cylinder was decorated with either vertical or horizontal stripes (the two conditions)
the stripes were black and white, high contrast and a variety of widths
the kittens were allocated to one of the two conditions and were placed in the cylinder for five hours a day
the kittens also wore a wide collar so they could not see their own bodies, which also limited their vision to about 130 degrees
a top cover/lid was placed on the cylinder whilst they were in there
the cats’ behaviour and brain neural patterns (in 2 anesthetised cats) were measured
what were the behavioural findings in blakemore and cooper?
the kittens often bumped into things
horizontally reared kittens would only respond to a rod being shaken at them if it was shaken horizontally and not vertically
showed no startle responses when an object or hand was thrust in front of them
their visual placing was impacted: they did not stretch their paws out when they were held out to be put down on a table. They only did when they felt the table
these effects seem to disappear after 10 hours in the well lit room but their tracking of moving objects remained jerky and they were still clumsy.
what were the neurological (brain) results of blakemore and cooper?
2 of the kittens were anaesthetised (with their eyes open) and had an electrode an inserted into their visual cortex to measure neural activity. One kitten had been reared in a vertical environment, the other horizontal
a normal cat’s pattern of neurons would have a balance of horizontal and vertical patterns
they found that kittens appeared to suffer from ‘physical blindness;
they found the kittens would show patterns of neurons in the same orientation as their reared environment
they showed little activity when shown images opposite to their original environment
conclusions of blakemore and cooper?
early visual experiences can modify a kitten’s perception in term of their behaviour and biology
the brain can change as a result of experience (plasticity)
brain development can be affected nurture
what is the hippocampus?
bilateral brain structure (we have a left and right hippocampus)
role is memory and spatial navigation
right is predominantly for spatial navigation
left is for episodic memories
what is the anterior hippocampus?
the front of the hippocampus
what is the posterior hippocampus?
the back of the hippocampus
what is white matter?
axons that connect the grey matter
makes up 60% of the brain
what is grey matter
the cell bodies
lies on the surface of the brain
makes up 40% of the brain
what was the aim of Maguire?
to investigate whether experience does actually change the structures of the brain
who were the ps in the experimental condition in maguire?
16 male London taxi drivers
32-62 years
right handed
had been licenced for more than 1.5 years
average time spent training on the Knowledge test was 2 years
healthy general medical, neurological and psychiatric profiles
who were the ps in the control group in maguire?
non taxi drivers’ scans were selected from the structural MRI scan database at the same unit where the taxi drivers were scanned
50 in total
age range 32 - 62 years (same as experimental conditions)
right handed
no health problems
