Draganski et al. (2006)

Title

temporal and spatial dynamics of brain structure changes during extensive learning

Background

several studies have demonstrated learning-dependent chnages in the adult human brain and suggested anatomical correlates for investigatiom, musicval leatning disabilities etc.

Aim

to investigate possible learning-induced structural plasticity of the adult human brain as well as to investigate functional and structural correlates of learning and memory

Participants

38 German medical students (21 female, 17 male)

mean age 24

average grade of the group matched the average grade of the medical exam that year

control subjects were sex-and-age-matched non-medical students

Procedure

MRI scans x3

1. 3 months before the exam

2. first or second day after the exam

3. 3 months after the exam

- controls were scanned at the same first 2 times as the medical students

Results

medical students' amount of grey matter increased in the posterior parietal cortex (PPC), associated with storage of visual short-term memory, in inferial parietal cortex and in posterior hippocampus.

grey matter decrease was found in the occipital-parietal lobe.

the grey matter in the hippocampus continued to grow after the exam (contradiction to hypothesis since grey matter increase could not be induced by learning)

Conclusion

the results indicate that the acquistition of a great amount of highly abstract information (formation of new memories) may be related to a particular pattern of structural grey matter changes in particular brain areas

Method

quasi

Critical thinking: methodological considerations

strengths:

- little bias

- high ecological validity

limitations:

- ethical problems

- limited control

- impossible to replicate (each individual has different brain structures)

Critical thinking: alternative explanations

as there was no control of external stressful experiences of the participants, the brain structure may not only have been affected by the stress of studying for the intense exams

Critical thinking: gender bias

as a balanced ratio of male and female medical students were used in the experiment, the study does not exhibit gender bias

Critical thinking: ethical considerations

the study was ethical because it can be assumed that the participants consented, were not deceived, were debriefed, could withdraw, and were protected from mental and physical harm while their identities remained confidential

Critical thinking: cultural considerations

as the study took place in Germany, it is considered culturally biased because the nation is recognized as a western, educated, industrial, rich, democratic country and is not representative of other populations

Critical thinking: applications

the results of this study are applicable in the sense that the results imply the effects of stress and intense studying on the structure of the brain, proving useful when evaluating the validity of various pressuring conditions

How does this study demonstrate neuroplasticity?

the study implies that the brain is "plastic" due to the altering volume of components of the brain due to the effects of continuous studying and stress, showing that the brain is subject to changing neural connections and structure throughout the lifetime, having various effects on the mind

How does this study demonstrate techniques used to study the brain in relation to behavior?

an MRI scan was used in this experiment because it provides a detailed 3D image of the brain and the size and structure of its different parts, accurately demonstrating the development neurplasticity but no cause and effect relationship