Biological - Neuroplasticity (Experiments) Flashcards
Merzenich et al (1984) aim
○ TO investigate how cortical remapping occurs in the sensory cortex.
Merzenich et al (1984) method
○ Sensory inputs of the fingers of each hand were mapped.
§ Electrodes were inserted in the cortical area and tested by researchers to map it out.
○ The third digit (middle finger) was amputated.
○ 62 days later a remapping was done to see how the cortical are had changed.
Merzenich et al (1984) results
○ The first mapping showed
§ There were 5 distinct areas in the brain for each finger.
§ Adjacent fingers were found adjacently in the cortex.
○ The Second mapping showed
§ After the amputation the adjacent areas of the cortex spread to occupy unused area.
Merzenich et al (1984) conclusion
○ Cortical remapping of sensory inputs from the hand occur in 62 days in owl monkeys.
Merzenich et al evaluation
Permanent harm to owl monkeys.
Dragaski et al (2004) aim
Investigate whether the human brain can change its structure in response to environmental demands
Draganski et al (2004) method
○ Sample
§ Random Sampling design
§ Self-selected sample
○ They allocated a sample of volunteers into two groups.
§ Jugglers
§ Non-Jugglers
§ They made sure no participant had juggling experience.
○ The first brain scan was performed before the experiment.
○ Participants in the juggler group began to learn juggling for 3 months.
○ After the 3 month period a second brain scan was performed.
○ The participants were instructed not to juggle for 3 months.
○ A third brain scan was performed.
○ The control group had brain scans at the same time and did not learn juggling.
Draganski et al (2004) results
○ Comparison of the first brain scans showed no differences.
○ Comparison of the second brain scan showed that
§ Jugglers had more grey matter in the brain.
□ Especially in the mid temporal area in both hemispheres.
§ These areas were known to be implicated with movement.
○ Comparisons of the third brain scan showed
§ Decrease of differences.
§ Significant more grey matter than control group.
○ Better jugglers had much more significant brain changes.
Draganski et al (2004) conclusion
○ As participants learnt a juggling routine, certain areas of the brain grow.
○ A lack of practice leads to a shrink but not to the initial state.
Draganski et al (2006) aim
○ Investigate the effect of reading on the brain.
Draganski et al (2006) method
○ Sample
§ 38 medical students.
○ He scanned the brains of the students 3 months before exams.
○ He then scanned the brain after examination.
○ He then scanned the brain a third time after 3 months of the exam.
Draganski et al (2006) results
○ No differences in regional grey matter at the baseline.
○ Two major changes
§ Increase of grey matter in parietal cortex
□ Did not decrease by the third scan
§ Increase of grey matter in the posterior hippocampus.
Draganski et al (2006) conclusion
○ Stress lead to the reduction of grey matter in hippocampal regions.
This meant that learning did make the brain gain grey matter.
Maguire et al (2000) aim
○ Investigate the brains of London Taxi drivers.
Magurie et al (2000) method
○ Sample
§ 16 right handed male taxi drivers.
§ Average pre-licensning time 2 years.
§ Average 14 years experience.
§ 50 healthy right handed male non-drivers
○ Both groups got their brain scanned.
§ MRI (Magnetic Resonance Imaging)
