Working memory capacity predicts dopamine synthesis capacity in the human striatum

Abstract

Evidence from psychopharmacological research has revealed that dopamine receptor agents have opposite effects on cognitive function depending on baseline levels of working memory capacity. These contrasting effects have been interpreted to reflect differential baseline levels of dopamine. Here we demonstrate for the first time that working memory capacity as measured by listening span predicts dopamine synthesis capacity in the striatum, indicating that subjects with low working memory capacity have low DA synthesis capacity in the striatum, whereas subjects with high working memory capacity have high DA synthesis capacity in the striatum.

Figure 1.

The correlation between listening span and K_i values from the left caudate nucleus.

Figure 2.

The mean raw axial (MR coregistered) whole-brain FMT PET K_i images from the high-span group (left) and from the low-span group (right) overlaid on a normalized MR image. Data represent K_i values. The right is right according to neurological conventions.