Context/Background
Biological workings in the brain influence behaviour in humans + animals
In the visual cortex of the brain, orientation-specific cells change the kind of stimulus they respond to, depending on an animal's early visual environment
This study shows the plasticity of a kitten's brain, as neurones originally conditioned to respond to horizontal or vertical orientation can switch when required
Physical structure of human and cat brains are similar, and their brains have a control of visual stimuli correlated to changes in RNA structures
Neurones of the visual cortex are selective for the orientation of lines and edges in the visual field
Aim
To investigate development of primary visual cortex and to find out if some of it's properties are innate or learned
Method
Lab experiment, independent measures
Iv= whether kittens were reared in horizontal or vertical environment
Dv= visuomotor behaviour once placed in an illuminated environment
Procedure
Kittens studied from birth and randomly allocated to 2 conditions, 1 from each condition were housed in completely different dark rooms, for 2 weeks and put into a stripy cylinder for 5 hours a day
The cylinder consisted of a clear glass platform inside a cylinder, where the inner walls were black and white stripes, either vertical or horizontal
Kittens were not upset and they sat calmly inspecting the walls in the tube.
The routine stopped at 5 months and they were taken for several hours a day into a small, well-lit furnished room and they were observed and recorded
At 7.5 months, 2 of them were anaesthetised so their neurophysiology could be examined
Findings
Both kittens were initially visually impaired and showed no startled response when an object was thrust at them
Pupil responses were normal when reacting to light intensity
They guided themselves by touch and got scared when reaching edges of tables
The kittens raised in horizontal environments could not detect vertically aligned objects, and vice versa
Kittens recovered normal vision in 10 hours but always tried to touch things beyond their reach = impaired depth perception
They suffered from 'physical blindness'
Conclusions
Visual experiences in early life of kittens = modify brains = profound perceptual consequences
Visual cortex = part of the ocipital lobe at the back of the brain
visual cortex adjusts itself during maturation
Nervous system adapts to match probability of occurrence of features of visual experience
Brain development is determined by functional demands rather than pre-programmed genetic factors
Evaluation
Research method- Lab experiment = scientific apparatus (cylinder) and high control, hard to generalise to humans but cats do have similar vision to us
Data type- qual and quant
Ethics- Some pain and distress for the cats as well as mother seperation
validity- standardised procedures = high reliability and low ecological validity
Reliability- highly replicable and only 2 kittens = limits reliability
sample bias = 2 kittens so a small sample, they could've been abnormal reducing validity and reliability