5-HTT, MAOA and 5-HT2a genotypes and duration representation parameters: PSE, RSE and .

<p> = total number of subjects.</p

The distribution of carriers of different genotypes of COMT, DAT and DRD2 genes in the sample.

<p> = total number of subjects.</p

Duration discrimination paradigm.

<p>(Adapted from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012650#pone.0012650-Sano1" target="_blank">[37]</a>.)</p