Blakemore + Cooper

• Cat intelligence-capacity of domesticated cats to learn, solve problems and adapt to environment
• Tufts- brain structure of cats and humans similar- both have cerebral cortices + are gyrencephalic
• The thalamus of a cat is responsible for- sleep, memory (from sensory data)
• Kittens brains have neuroplasticity- cats possess visuall recognition memory + can adapt to changing environmental stimuli
• In a normal cat neurones of the visual cortex are selective for the orientation of lines and edged in the visual field + preferred orientation of different cells are distributed all around
• Hirsch + Spinelli- early visual experience can change neural organisation in kittens- kittens reared in verticalll or horizontal stripes- out of 21 neurones all monocularly driven- all but one case orientation matched parent experienced by eye
• allowed normal binocular vision rather than monocular vision
• AIM- investigate development of primary visual cortex + find if some properties are innate
• Lab experiment with independent measures design

  • IV- horizontal or vertical environment
  • DV- visumotor behaviour once placed in regular environment
• Two kittens uses to study neurologic effects
• Kittens housed from birth in the dark- from 2 weeks placed into a cylinder with a clear glass platform with either horizontal or vertical stripes for 5 hours a day
• Collar restricted view to 130- kittens did not seem upset + sat fo long periods inspecting walls of tubes
• stopped at 5 months- end of critical period for visual defects
• Kittens taken to a well lit furnished room- visual reactions observed+ recorded- at 7.5 months two kittens (one from each condition) taken to examine neurophysiology
• All kittens initially extremely visually impaired

  • no startle response when object thrust toward them
  • guided themselves by touch
  • frightened when reached edge of surface being stood on
• Only eyes of kitten raised vertically followed a rod held vertically + vice versa
• Kittens recovered from many deficiencies within 10 hours of normal vision
• Permanent defects-always followed objects with jerky, clumsy head movements- tried to touch objects far away
• neurophysiological- no evidence of severe astigmatism-distinct orientation selectivity, kittens suffered from ‘physical blindnes’

  • 75% of cells in both cats binocular + almost alll responses were like normal kitten
  • distributions abnormal- not one neurone had optimal orientation within 20 anisotropy- directionally dependent
  • no obvious large regions of ‘silent’ cortex corresponding to missing cortical columns observed
• Concuded- visual experiences of early life of kittens can modify brains and have a profound perceptual consequences
• Concluded- kittens visual cortex may adjust itself during maturation to nature of visual experience- nervous system may adapt to match probability of occurrence of features in visual output
• Concluded- brain development determined by functional demands made rather than genetic factors - environment can determine perception at behavioural + physiological level- in cats- unsure if results generalisable to humans