Biological Approach: Localisation & Plasticity

Question 1

What is localization of function?

Answer 1

• the theory that specific parts of the brain are responsible for specific behaviors or cognitive processes
• although we know that some parts of the brain do play specific roles in behavior, rarely does a part of the brain work in complete isolation

Question 2

What is distributive processing?

Answer 2

• in memory research, we argue that the cognitive process is the result of distributive processing rather than localization of function – several parts of the brain have to work together in order to help us create and retrieve memories

Question 3

Define plasticity

Answer 3

• refers to the brain’s ability to alter its own structure following changes within the body or in the external environment

Question 4

What is dendritic branching?

Answer 4

• every time we learn something new, the neurons connect to create a new trace in the brain
• this is called dendritic branching because the dendrites of the neurons grow in numbers and connect with other neurons

Question 5

What is neural pruning?

Answer 5

• the process by which extra neurons and synaptic connections are eliminated

Question 6

HM (Milner) can be used to explain…

Answer 6

Localization of function - hippocampus

Question 7

Draganski (2004) can be used for…

Answer 7

neuroplasticity, formation of synapses, neural pruning, ethics/research methods

Question 8

Draganski (2004) - aim

Answer 8

• to see whether learning a new skill - in this case, juggling - would have an effect on the brains of participants

Question 9

Draganski (2004) - procedure

Answer 9

• all participants were non-jugglers at the start of the study
• each participant had an MRI scan at the start of the study to serve as a base rate for grey matter and brain structure
• participants were allocated to one of two conditions - the jugglers and the non-jugglers
• those in the juggling condition were taught a three-ball cascade juggling routine and asked to practice this routine and to notify the researchers when they had mastered it - at that point, the jugglers had a second MRI scan - after the scan, they were told not to juggle anymore and then a third and final scan was carried out 3 months later
• the non-juggling group served as a control group for the duration of the study
• to analyze the MRI scans, the researchers used voxel-based morphometry [VBM] to determine if there were significant differences in neural density (grey matter) in the brains of jugglers vs. non-jugglers

Question 10

Draganski (2004) - findings

Answer 10

• from the baseline scans - taken before the study began - they found no significant regional differences in the grey matter between the two conditions
• however, at the end of the first part of the study, the jugglers showed a significantly larger amount of grey matter in the mid-temporal area in both hemispheres - an area associated with visual memory
• three months after the participants stopped juggling - when many were no longer able to carry out the routine - the amount of grey matter in these parts of the brain had decreased
• there was no change over the duration of the study in the non-juggling sample

Question 11

Draganski (2004) - conclusion

Answer 11

• ceasing activity leads to neural pruning whereas learning a new skill leads to dendritic branching and new neural networks being created
• it appears that juggling relies more on visual memory - that is, the perception and spatial anticipation of moving objects than on “procedural memory” which would more likely show change in the cerebellum or basal ganglia