IB Psych Studies

Kuhl et al. (2003)

Found that American infants (9 months) who were exposed to live play sessions in Mandarin could discriminate Mandarin phonetic sounds from English as well as infants in Mandarin speaking environments.

By 9 months, infants usually lose their ability to distinguish non-native sounds (phonetic pruning) and this study showed that live social interaction can reverse the decline - high plasticity in the infant brain.

Maguire et al. (2000)

Found that London Taxi drivers had significantly higher volume in their posterior hippocampus and a lower volume in their anterior hippocampus compared to non-taxi driving controls. The amount of increase was positively correlated with time spent as a taxi driver.

The taxi drivers also performed better on spatial representation tasks, indicating that the posterior hippocampus is associated with spatial representations, and that the brain can change in response to environmental demands (experience-dependent neuroplasticity).

An alternative reading to this is that an innate difference in hippocampus structure instead of only experience-dependent neurplasticity contributes to the success of the Taxi drivers.

Merzenich et al. (1996)

Kids with language learning impairments (LLIs) have significant deficits in rapid auditory processing.

The study found that a computer-based training program reduced the deficit in a few hours of training. This showed that behavior training can remediate those deficits and change human behavior without altering by the brain. (Reduced ability to create a causal link between brain development and human behavior).

Felitti et al. (1998) - ACE Study