Biological area Behaviour is controlled by physiological changes within the body, as opposed to environmental factors Human behaviour should be investigated using scientific, rigorous methodology The things that people think and feel, say and do are determined by the make up of the nervous system, brain structures, genetics and DNA, chemicals and hormones, and evolutionary factors

Blakemore and Cooper (1970) Impact of early visual experience Area: Biological Area Theme: Brain plasticity

The brain Is it predetermined or can it change?

The brain has plasticity This means the brain is not plastic – it is the opposite. The brain can change and adapt over time due to experience

Let’s think about origami This can be difficult however, the more times you try, the easier it becomes The same happens in your brain! Through a growth in synaptic connections

Blakemore & Cooper 1970

Background: B&C aim… Researchers questioned ‘Does brain plasticity/development occur due to experience or nature?’ How they did this was by looking at… What physiological and behaviour effects does a limited visual experience have?

Method: Where? Controlled artificial environment Who? New born kittens Immediately placed in a dark room What method is this? What's wrong here? Lab experiment

Method: At 2 weeks of age, the kittens were randomly placed into one of two conditions for five hours a day: A horizontal or a vertical environment What type of design? IV Independent measures design

Horizontal or vertical environment?? The kittens had to stand on a clear glass platform which was inside a tall cylinder of which the inner surface was covered with either horizontal or vertical, black-and-white stripes They were required to wear a wide black collar. This prevented them from seeing their own body and ‘beyond their world of stripes’.

The Dependent Variable (DV) was then measured: this was whether kittens raised in a horizontal environment could detect vertically aligned objects And if kittens raised in a vertical enviroment could detect horizontally aligned objects

What did they find?

Results: All the kittens were extremely visually impaired no visual placing when brought up to a table no startle response when an object was thrust towards them

All kittens showed behaviour blindness, meaning that they could not detect objects or contours that were aligned in the opposite way to their previous environment Deficiency from their early deprivation

What happened to the kittens after? After five months, exposure to the experimental conditions ended and the kittens were then placed for several hours a week from their dark cage to a small, well-lit furnished room

What happened to kittens after? 10 hours the kittens showed visual placing and some startled responses Permanent damage = clumsy and trying to touch things beyond reach

After 7 and a half months, two of the kittens, one from each environment were anaesthetised and their neurophysiology was examined Found: no evidence of astigmatism (blurred vision). There was, however, evidence of ‘physical blindness’ (Explaining inability to perform orientation selectivity)

Conclusions… Brain plasticity??

Conclusions Brain development is clearly affected by early experiences and environmental factors rather than just genetics

Conclusions There is clear evidence of brain plasticity – ‘the visual experience of these animals had modified their brain’ and therefore has serious perceptual consequences. The kittens’ visual cortex adjusts during development as a result of its visual experiences.

Based on your handouts… PEEL one strength and one weakness Complete handout 1 Based on your handouts… PEEL one strength and one weakness

Based on your evaluations… You are the researcher, what would you change? Complete pages 9-13 Homework: Complete pages 1-9