Yesterday I mentioned that brain scientists are actively investigating the neural processes underlying personality differences in behaviour. A very nice example of this research is to be found in the latest issue of Cognitive Brain Research. Michael Cohen and his colleagues linked personality testing, fMRI and genetic analysis to look into how personality may correlate with different neurocognitive ways of handling an economic game. Here is the abstract:
Psychologists have linked the personality trait extraversion both to differences in reward sensitivity and to dopamine functioning, but little is known about how these differences are reflected in the functioning of the brain’s dopaminergic neural reward system. Here, we show that individual differences in extraversion and the presence of the A1 allele on the dopamine D2 receptor gene predict activation magnitudes in the brain’s reward system during a gambling task. In two functional MRI experiments, participants probabilistically received rewards either immediately following a behavioral response (Study 1) or after a 7.5 s anticipation period (Study 2). Although group activation maps revealed anticipation- and reward-related activations in the reward system, individual differences in extraversion and the presence of the D2 Taq1A allele predicted a significant amount of inter-subject variability in the magnitudes of reward-related, but not anticipation-related, activations. These results demonstrate a link between stable differences in personality, genetics, and brain functioning.
Note how juxtaposing the various types of data effectively unveil insights into brain activity we would have no possibility of gaining using just one method. Combining behavioural, imaging, and genetic data, will probably soon become the gold standard of cognitive neuroscience.
Cohen, M. et al. (2005): Individual differences in extroversion and dopamine genetics predict neural reward responses. Cognitive Brain Research 25: 851-861.