Blakemore and Cooper Flashcards
BIO: Brain Plasticity
What is the theme of B+C ?
Brain plasticity (how brain can change shape and size)
What did Hubel and Wiesel find ?
Neurones of visual cortex are selective for the orientation of lines in visual field around a point.
What did Hirsch and Spinelli report ?
Reported that early visual experience can change neural orientation. They did this by exposing one cats eye to horizontal and one eye exposed to vertical. Found that neurones were monocularly driven.
What is different between B+C and Hirsch and Spinelli ?
Hirsch and Spinelli found that their experience led cats to be monocularly driven whilst B+C, were looking cats still being binocularly driven.
Aim of B+C
To investigate physiological and behavioural effects of restricted early visual experience of visual cortex.
-Also to see if brain plasticity is affected by nature or nurture.
What was the experimental method of B+C ?
Laboratory experiment
What is the experimental design of B+C?
Independent measures design.
What is the sample of B+C ?
2 kittens randomly allocated either visual or horizontal conditions. Used to study behavioural and neurophysiological effects.
Procedure of B+C
-Kittens were housed from birth in dark room.
-2 weeks = put in cylinder with vertical or horizontal stripes stood on a glass floor and with a cone around the head so they cant see themselves.
When was routine stopped in B+C ?
5 months old as this was past the critical period in which total deprivation causes psychological deficits.
What happened to kittens when routine of being in cylinder stopped ?
Then taken for several hours each week from dark cage to small well-lit room furnished with tables and chairs. Their visual reactions were observed and recorded.
What happened to kittens at 7.5 months old ?
Two kittens were anesthetised so their neurophysiology could be examined.
Results of behavioural observations in Blakemore and Cooper ?
-Had no visual placing but this wore off in about 10 hours.
-Kittens raised only with horizontal lines could see horizontal objects (and vice versa).
-Permanent deficit was that cats often reached out to touch something that was far away.
Results of neurological observation in B+C ?
-75% of cells in both cats were clearly binocular.
-No evidence of sever astigmatism.
-Horizontal cats did not respond to lines within 20 degrees of vertical rotation (same for vertical cats).
Conclusions of B+C ?
-Visual experience can modify cats brains.
-Kittens visual cortex can adjust itself during maturation.
-Kittens used parts of their nervous system adapts to match the visual experience, rather than degenerating.
-Demonstrates brain plasticity.
