Biology - Macgurie Flashcards
What are cognitive maps
Where are these stored
Where is spatial memory stored in our brains
Our mental maps of our environment
Where mental maps are stores to help our navigation
Hippocampus
One in each hemisphere
Associated with memories where our spatial navigation is
Why is white matter
What is grey matter
Neural connections in our brain
Lies on the surface of the brain dense in neural cell bodies and associated with high order of thinking
What is the knowledge
And why were London taxi drivers used ?
All London taxi drivers need to pass the knowledge have to learn 25,000 streets 20,000 landmarks within 6 mile radius of Charing Cross 2-4 years to pass
Knowledge is good to test memory - long term ability (effect of plasticity )
Sample
Taxi drivers- 16 right handed London taxi drivers 32-62 mean 44
All licensed taxi drivers for at least 1.5 years average time in konewledge -2 years all had general medical neruological physiological
Non taxi drivers
50 right handed 32-62 scanned for mri database of university college London no women left handed nor under 32 or over 62 no health problem
Procedure
1 Mri scans magnetic fields and radio waves taking picture of brain brain blind experimenter analysed Mri scanner results didn’t know which scan was taxi or no taxi
2- vbm - voxel based morphemetry - measures volume of brain , measures grey matter (density) in brain provides a 3d measurement
3: count pixels in Mri images pixel is a 2d measurement of an area took 26 slices of brain to count pixels
24 slices of hippocampus 2 of the whole brain 12 slices each hemisphere
Results -
Vbm - increase in grey matter in taxi drivers left and right posterior hippocampus
Non taxi drivers - more grey matter in left and right anterior
Pixel counting - no difference in overall volume of non taxi drivers and taxi drivers hippocampus
Taxi drivers had a higher volume in posterior hippocampus
Ntd -higher volume in anterior of hippocampus
Correlation all results
See if there was a relationship between : time spent as a taxi driver including time learning the knowledge and the hippocampus volume
Found a positive correlation between time spent as a txt driver and the right posterior hippocampus
Negative correlation between time spent as a taxi driver and volume of anterior hippocampus
Conclusion
Hippocampus can change as a result of experience as a taxi driver evidence for plasticity
Time spent a a taxi driver affects volume of right posterior hippocampus
Research method
Quasi design - iv naturally occurring either a taxi driver or non taxi driver , subject variables - individual differences
Controls e.g right handed
Physiological methods
Braving imaging tachniwue only way to see volume of hippocampus and not directly observable - can be costly - blind experiment or any a,send results no response bias
Correlation all analyses helped establish relationship between volume of hippocampus and time spent as a taxi driver to confirm that time spent as a taxi drivers was cause of hippocampus volume
Type of data
Lavatory setting allows highly technical equipment and allow precise measurements of data vbm and pixel counting allows statistical analysis and differences between two groups ensure reliability and validity comparison of vbm and pixel counting concurrently valid
Pixel counting - volume of grey matter mm3
Ethics
Carried out according to bristles ethical guidelines. 1993
Gave consent had right to withdraw , not deceived
Validity
Matching gender , handed ness, good lsychological and physical health volume differences both same in pixel counting , vbm concurrently valid
Because of being a axi driver causes change in hippocampus not because of difference already passed in hippocampus supported by correlational evidence shows volume hippocampul volume correlated with time spent as taxi driver
Results compared with blakemore and cooper shows validity
Reliability
Highly controlled experiment - collected quanta give data could be repeated and test retest reliability ,
Sample
Not everyone of sample is typical population may be that not everyone’s brain responds in the same way to environmental demands of doing the knowledge clear gender bias - can be assumed that female and male brains operate similarly in terms of spatial memory
Ethnocentrism
Not ethnocentric brain plasticity I hippocampus in response to spatial demands of environment is affected by anatomy and physionogmy
Carried out experiment of species specific behaviour it assumes London cab drivers brain and general population will have similar capacity in terms of spatial memory ( brain plasticity )
