Draganski et al (2004)

Aim

To investigate whether structural changes in the brain would occur in response to practicing a simple juggling routine

Method

A mixed design method, where participants volunteered to take part and using a random sampling design they were allocated into 1 of the two groups. All participants had no juggling experience prior

Procedure

Participants were randomly divided into two groups, jugglers and non-jugglers. The jugglers group spent 3 months learning a classic juggling routine with 3 balls, then followed another 3 month period where the jugglers were asked to stop and not practice at all. Throughout the total of 6 months, the non-jugglers (control) never practiced juggling. Three MRI scans were conducted on both groups; one before the experiment, one after 3 months, and one after 6 months.

Results

The first MRI scans were conducted showed no differences in brain structure between the two groups. After 3-months of practice, the jugglers had significantly more grey matter in the mid-temporal area of the cortex in both hemispheres (area known for coordination of movement). After 6 months, the differences between the two groups decreased, although the jugglers had more grey matter in these areas than at the first MRI

Conclusion

Grey matter grows in the brain due to environmental demands (like learning a news skill) and shrinks in the absence of stimulation (lack of practice). This shows there is a cause and effect relationship between learning and brain structure

Suggestion in terms of neuroplasticity

Suggests that the brain adapts in response to environmental demands

Strengths

• strong biological evidence, before/after making effect clear

• Same participants scanned before/during/after → controls for individual differences → internal validity increases

• MRI brain scans → scientific, reliable, not based on self report

• Longitudinal → shows not just change but the reversal

Limitations

• small sample size (24) → limits generalisability

• Low ecological validity; juggling is very specific task → brain changes might be different for more general skills (eg. Language, emotions)

• Increase in grey matter, but what changed biologically?

• Relatively short term period → no long-term permanence of brain changes shown