Psychology - Core Studies - Blakemore and Cooper (1970)

title?

“Development of the brain depends on the visual environment”

aim?

• to investigate the behavioural consequences of exposing a kitten to either vertical or horizontal orientations,

• to investigate the neurophysical effects of exposing a kitten to either vertical or horizontal orientations,

sample?

kittens raised in complete darkness for first 2 weeks of their lives, 2 use for electrodes,

method?

lab experiment:

• IV = horizontal or vertical lines,

• DV = behaviour, was it like any other cat?, neural activity,

procedure?

kittens spent majority of time in the dark,

2 weeks - 5 months → placed in a cylinder for 5 hours a day and then back to darkness,

cylinder = 46 × 200cm, either horizontal or vertical b/w stripes,

then into a normal environment and observed,

results?

in a normal environment cats had difficulties with visual placing and behaviour,

vertical cats - difficulties judging horizontals e.g., jumping between ledges,

horizontal cats - difficulties judging verticals e.g., jumping heights,

often used tactile instead, initially cats didn’t have a startle response, visual placing was still limited after 10 hours but had developed with a startle response.

procedure of neural activity?

cats anaesthetised,

pinned eye open and placed electrode into the visual cortex,

presented with different orientations of lines,

results of neural activity?

no neurones had preferred orientation within 20° of opposite orientation ie horizontal cats could see 160°-200°, vertical cats could see 340°-20°

conclusions?

some vision is innate but some is determined by early visual experiences,

Nature - papillary responses, neuroplasticity

Nurture - horizontal vs vertical judgements,

validity?

Face → tests show results for behavioural and neurophysical effects (observation vs electrodes),

Concurrent → results from neurological tests and behavioural observations align,

Construct → builds on tests from Hubel and Wiesel (1962),

Ecological → cats have similar visual cortexes to humans but it was under a lab experiment,

Temporal → neuroplasticity has been further proved e.g., Jacobs et al (1993),

reliability?

internal → neurophysical and observations produced similar results for each cat however neurophysical only on 2 cats, inter-rater (2 observers and a behavioural checklist),

external → standardisation,

usefulness?

develop further theories of neuroplasticity,

applications to education, exposing children to a variety of visual stimulants, rehabilitation of prisoners or those with brain damage,