8827600
Description
Flashcards by Dhara Bechra, updated more than 1 year ago
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Created by Dhara Bechra
almost 7 years ago
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| Question | Answer |
| Blakemore & Cooper (1970) - Impact of Early Visual Experience | In normal cats, neurons of visual cortex are selective for orientation of lines and edges in whole visual field - early visual experience can change orientation. Previous research, kittens reared with one eye viewing vertical stripes and other horizontal. Out of 21 neurons, 20-orientation, recpetive field matched pattern experience by that eye. |
| Aims & Research Questions | To investigate the influence of early visual experience on development of visual system in kittens. To test whether kittens raised in an environment of vertical or horizontal stripes would develop normal vision. |
| Research Method | Lab Experiment Independent Meaures Design |
| Sample | Kittens - born and raised in complete darkness until 2 weeks of age. |
| Procedure | Kittens put in apparatus for 5 hours a day. Kitten stood on glass table inside cylinder which was covered with either vertical or horizontal black and white stripes. Kittens couldn't see their own body because they wore a collar that restricted their visual field. |
| Procedure (2) | When kittens were 5 month old, they were taken out of cylinder and taken to a well-lit room, with tables and chairs and were observed. |
| Results | Within 10 hours, kittens could jump with ease from chair to floor. They were clumsy when chasing moving objects. Often bumped into table legs or furniture. Kittens tested for line recognition. Showed 'behavioural blindness'. |
| Results (2) | Those raised in horizontal environment could not detect vertically aligned objects. Only eyes of kittens raised with vertical stripes followed rod held vertically. When kittens were 7.5 months old, they were anaesthetised while neurons in visual cortex were studied. |
| Results (3) | 125 neurons from 2 cats, one horizontally and one vertically exposed, studied. Horizontal plane neurons didn't 'fire-off' in kittens raised in vertical environment, vertical plane neurons didn't 'fire-off' in kittens raised in horizontal environment. |
| Conclusion | Difference between differently reared kittens suggests that neurons change their preferred orientation according to stimulation they receive, matching ability of brain to respond to features in visual input. |
| Evaluation | High control Ungeneralisable Quantitative and Qualitative data collected Ethical issue- used animals, pain and distress High EV- reduced extraneous variables Replicable- procedure standardised |
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