Biological - Blakemore And Cooper Flashcards
What did harsh and spinelli do
Record kittens with one eye viewing vertical stripes and other viewing horizontal stripes. Found that eye received vertical stripes looked more at vertical images suggested neurons in the brain developed certain pathways according to the environment
What is plasticity
Visual cortex
Neurons
When experiences reorganise neural pathways in the brain . Brain changes to adapt to new environment.
Visual cortex- lights reflect off of images and into a electrical signals which are sent through neural pathways. It is in the visual cortex the images are seen.
Neurons- nerve cells which carry messages
Aim -
Investigate biological and behavioural effects of a restricted visual experiences and whether brain development plasticity occurs due to nurture
Samples iv dv
Sample- kittens birth to 1 year
Iv- if kittens were put in the cylinder of vertical lines or horizontal lines
Dv- biological behavioural effects this visual experience would have on brain development on plasticity
Procedure
From birth housed in completely dark room
2 weeks the placed in cylinder apparatus which was 46cm and 2 metres high .
The cylinder were either horizontal or vertical lines
Black and white contrast and variety of width
The kittens we’re randomly allocated to one of the conditions placed in the cylinder for 5 hours a day
Wore a collar so they couldn’t see own bodies about 130 degrees
A cover lid placed on cylinder
Behavioural results
Ability to move around- often bumped into things
Responses to objects to the rod was represented horizontally and vertically - tracking and moving objects were jerky horizontally reared would only respond if rods shaken horizontally not vertically .
Their startle responses - showed no startle responses
Their visual placing a didn’t stretch paws out when they were held out to be out down on the table only did if they felt the table
Statement on behavioural results
After 10 hours in well lit room seemed to disappear but clumsiness and objects still remained jerky
Biological results
2 of the kittens were anaesthetised and had electrodes inserted into visual cortex to measure neural activity one kitten had reared in vertical environment other in horizontal
A normal cats pattern of neurons would have a balance of horizontal and vertical others would be be appropriated to visual experience
Appeared to suffere from physical blindness
Showed little activity when shown images opposite to original environment
Conclusion
Early visual experiences can modify kittens perpception in terms of behaviour and biology
Brain an change as a result of experience
Brain development can be affected by nurture
Research method
Lab
Type of environment kittens were in was controlled - cylinder with vertical or horizontal lines
Strength able to conclude that it was the type of environment the kitten was in which cause perceptual difficulties and atypical neurological findings
Types of data
Quantative
- one cat was shown to favour the restricted orientation in which cats were raised
Provides scirentific evidence of brain plasticity in kittens
Quantitative - observation of kittens behaviour in response to two different environments placed in
Ethical
Conducted within strict ethical guidelines laid down by the home office for studies conducted on animals
Validity
High control - make sure it was the environment they were placed in had effect in visual experience - collars on , all same vertical lines - same height and width
Concurrently valid measured effect of restricted visual environment using behavioural and neurophysiological measures . Both showing evidence that kittens raised in horizontal visual environment did not see in the vertical orientation - opposite true
Supports development of kittens brains had been influenced by their environment
Ecological validity
Used real kittens in study can be generalised and representative
Lab lots of controls collars on them limiting 130 degrees vision same height 46 cm and 2 m wide etc real life kitten wouldn’t have this restrictions imposed. Behaviour may be different in real life
Reliability
Under cotnrolled conditions gave detailed instructions - possible for stuffy to be repeated and tested if could test retest reliability
Only 2 kittens one raised in vertical environment one in horizontal environment for neurological part larger sample needed to establish results were not just a fluke
