The link between creativity and baseline dopamine receptor availability in key brain regions is fascinating, especially when you attempt to consider how alleles pushing individuals along the schizophrenia spectrum might be adaptive.
Manzano et al (here) measured the binding potential of D2 receptors* with PET in the striatum, thalamus, and frontal cortex in healthy individuals and also measured them on a divergent thinking test. They found a significant relationship in the thalamus (A) only:
The low dopamine binding potential in the thalamus of those who scored highly on the divergent thinking test (i.e. are more creative) are probably related primarily to a reduced density of dopamine D2 receptors there.
One explanation for divergent thinking is that idea generation is based on random free association between concepts. So by increasing the quantity of ideas, the probability of coming up with some ideas good enough to reach consciousness and pass conscious filters for originality and flexibility will be higher.
Decreased dopamine binding potential in the thalamus could help this process because 1) it lowers thalamic gating thresholds, resulting in decreased filtering and less “autoregulation” of information and 2) it decreases inhibition of pyrimidal neurons in the prefrontal cortex, thus making prefrontal networks better at switching sets and combining diverse mental stimuli.
The link between tests of divergent thinking and impulsivity is hard to characterize, but it seems that impulsivity is negatively correlated with creativity as measured by divergent thinking. For example, Fuqua et al (here) found that reflective children had average z scores on the divergent thinking test of + 0.28 higher than the mean and that impulsive children had average z scores of – 0.30 lower than the mean.
Contrasting the findings of Manzano et al and Lee et al (briefly explained in my last post here), it seems that higher D2-receptor binding potential in the striatum is correlated with lower impulsivity. But, higher D2-receptor binding potential in the striatum trends towards higher creativity as proxied by divergent thinking tests (see B**). So the neurochemical data seems to be consistent with the behavioral data.
* That is, the ratio of dopamine-receptor complexes to free dopamine at equilibrium.
** Although the striatal findings weren’t statistically significant, there is a trend, plus the power wasn’t huge (PET scanning isn’t perfect and n = 14), and plus this is my blog so quit yer hollerin’.
Fuqua RW. 1975 An investigation of the relationship between cognitive tempo and creativity in preschool-age children. Child Development, link here.
de Manzano Ö, Cervenka S, Karabanov A, Farde L, Ullén F (2010) Thinking Outside a Less Intact Box: Thalamic Dopamine D2 Receptor Densities Are Negatively Related to Psychometric Creativity in Healthy Individuals. PLoS ONE 5(5): e10670. doi:10.1371/journal.pone.0010670