Individual differences m human behaviours including cognitive functions reflect the integration of genetic, epigenetic and environmental influences that regulate adaptation mechanisms across functional levels. How these different influences are integrated to regulate adaptation mechanisms across functional levels is a key question of contemporary research. One novel technique to investigate the integration of genetic and environmental influences at the level of neural networks and its relation to behaviour is genetic neuroimaging. We used this technique to investigate whether individual genetic differences influence the individual performance and task-related brain activity in working memory for emotional faces. Results revealed effects of variability in the gene for the synaptic protein dysbindin-1 on working memory performance and its neural correlates that depended on the type of emotional face expression. This suggests that genetic influences are integrated with environmentally-driven stimuli at the neural network level to regulate the behavioural response.
Interindividual differences are also reflected in the degree of impairment m cognitive functions such as working memory in patients with schizophrenia. We were interested in the biological basis of relatively preserved cognitive functions in a subgroup of the patients with schizophrenia. Using fMRI we compared brain activity related to accurate WM performance in patients with matched control participants. Patients and controls showed activity increases and decreases in different brain regions. This indicates that patients with preserved WM function may compensate insufficient support from dysfunctional regions through hyperactivation in less affected regions.