a,b. Mean confidence estimates for the two sequences in which participants were asked to rate the confidence of their decision.

<p>The red line represents the methamphetamine condition; blue represents the placebo condition, and green represents the combined amisulpride and methamphetamine condition.</p

Mean number of draws to decision.

<p>Mean number of draws to decision.</p

Mean number of draws to decision. Error bars are 95% confidence intervals.

<p>Mean number of draws to decision. Error bars are 95% confidence intervals.</p

a,b. Draws to decisions of the individual participants in two experimental conditions during their 3 visits.

<p>a,b. Draws to decisions of the individual participants in two experimental conditions during their 3 visits.</p

Association between polymorphisms and cognitive outcomes, controlling for gender and education level, in the entire sample of those at risk for psychosis and population controls.

<p>Association between polymorphisms and cognitive outcomes, controlling for gender and education level, in the entire sample of those at risk for psychosis and population controls.</p

Loadings of baseline performance for individual tests to three main factors (n = 181).

<p>Loadings of baseline performance for individual tests to three main factors (n = 181).</p

Scree plot of Eigenvalues for principle component factor analysis of neurocognitive variables.

<p>Scree plot of Eigenvalues for principle component factor analysis of neurocognitive variables.</p

Demographics.

<p>List of demographics for the 82 subjects included in this study, grouped by genotype. Data on educational level reached by the end of 1997 was collected from register of the Statistics Finland. Handedness data obtained at the time of MR scan.</p

DLPFC volume according to genotype.

<p>Dorsolateral prefrontal cortex (DLPFC) volume according to genotype at COMT Val158Met in men and women.</p

Clinical characteristics of participants with schizophrenia.

a<p>PANSS, Positive and Negative Syndrome Scale, assessment of the PANSS in the baseline and 9 year follow-up are not completely comparable (please see text in methods).</p>b<p>Social and Occupational Functioning Assessment Scale.</p>c<p>Equivalent to 100 mg daily chlorpromazine during the 9-year follow-up.</p