Biological (CONTMEMPORARY) - brain plasticity - MAGUIRE Flashcards
Define brain plasticity
Capacity of the brain to modify the organisation of its neural networks according to the particular experiences of the body
Define the limbic system
Involved in behaviours that satisfy certain motivational, learning and emotional needs including feeding fighting escape and mating
Define the hippocampus
Part of the brain linked to conversion of information form short term to more permanent memory. Found inside each hemisphere of the brain and is thought to play an important role in facilitating spatial memory and navigation - clear evidence of localisation of function. So you can navigate your environment because you connect the memory of a chair ti a certain location with the information of how you got there and the ability to remember the location of different places and things. Helps create mental maps and explains role of hippocampus in our navigational abilities
Two parts of hippopotamus
- Anterior - front part which is involved in new learning about environmental layouts
- Posterior - back part which is involved in using previously learned information about the environment
Explain what an MRI scan is
Involve use of radio waves obtaining 3D images of the brain. People are exposed to strong magnetic field which is turned on and off rapidly in the presence of a radio wave. Detector reads signals form the atoms in the brain which respond to the magnetic field and using a computer map the structure of the tissue
Explain what pixel counting is
Analyses MRI scan info in 2D. Involved analysing photographic slicing made through the hippocampal region of the participants brain. Total hippocampal volume was calculated by adding up the pixels from each slice and multiplying it by the distance between each slide
What is VBM
Voxel based morphometry
Analyses MRI scan info in 3d. It identifies differences in the density of the grey matter in the brain. The denser the area is the more neural connections are in existence suggesting greater use of that area of the brain
Aim
The hippocampus in the human brain is the structure associated with spatial memory and navigation
Sample
16 taxi drivers who were all healthy right handed male London taxi drivers with a mean age of 44 years (32-62yrs) mean time as a licensed London taxi driver (passed the knowledge) 14.3 yrs (1.5-42yrs)
Sampling method to obtain taxi drivers
Volunteer
Describe the control group
Group drawn form MRI database at the university college London. Controls were chosen from the database who did not drive taxis. From that group a matching process was done in the basis of health, right handedness, sex, mean age and age range
Give the numbers of those in control group
50 in final matched group used for VBM analysis to compare their brain activity with that of taxi drivers
A Final Cut of that 50, 16 were precisely matched on age to the taxi driver sample were used to compare the taxi drivers pixel counting analysis
Describe the research method
Quasi experiment
IV whether the participants were a London taxi driver or a person who did not drive taxis was naturally occurring so could not be manipulated
DV volume of the hippocampi including the anterior, body and posterior regions measured by analysing MRI scans of participants brain using the two techniques of VBM and pixel counting
Study used independent measures, matched pairs as participants were matched to a control group
Procedure
Taxi drivers were individually given a MRI scan at the welcome department of cognitive neurology at university college London
MRI scans were analysed using VBM and pixel counting
VBM - brains of 16 taxi drivers were compared to those of non taxi drivers to see if there were any differences in structure
Pixel counting - compared volume of anterior and posterior cross sections of the taxi drivers hippocampi
How were the images analysed
By one one person experienced in technique and blind to whether the scan was of a taxi driver or a control and the VBM findings. This procedure allowed the total hippocampal volume to be calculated
