Blakemore and Cooper

Blakemore and Cooper

1. Aim

   • To test whether kittens raised in an environment of vertical or horizontal stripes would develop vision
     • Looked at behavioural consequences

2. Lab

   • Participants= lab raised kittens
     • Kept in the dark in till 2 weeks
   • Independent measures design
     • Independent variable= which orientation
       • Dependant variable= neurophysiology effects and behavioural consequences

3. Method

   • From 2 weeks- to 5 months
     • 5 hours a day in the visual display apparatus
       • Cylinder- 2m x 46 cm
         • Half way up= glass platform
   • Kittens placed in a black cone shaped collar
     • Could not see themselves if they looked down
       • Only saw V or H lines
     • From the age of 5 months
       • Daily taken into a well lit room with chairs from their dark environment
         • Visual reactions observed in the way they moved and navigated
           • Two kittens tested biologically- 7.5 months
             • Anaesthetising the cat with eyes open
               • presented with vertical or horizontal bright lights
                 • Natural startle response ?
                   • Rod was moved to kitten vertically and horizontally to test this
                     • Only react if it was in the same orientation they were raised in
             • Results
               • 75% of the kittens the neurones were binocular
               • Polar histograms of neurone activity
               • H kitten= V neurones not active
               • V kitten= H neurones not active
               • Normally both the V and H neurones would be active

4. controls

   • Age
   • The conditions
   • Time in apparatus
   • The floor
   • The collar

5. Results

   • pupils responded normally to bright light
   • Behaviour was different
     • Moved around environment by touch not vision
     • when reaching the end of a surface they did not outstretch a paw
     • Many of the problems disappeared in 10hrs of being in a well lit room

6. conclusions

   • No evidence to suggest that areas of the cortex were silent or that cortical cells were missing
     • changes not causes of degeneration
   • Differences in the differently reared kittens
     • suggests that neurones change their preferred orientation according to stimulation