Figure 5.

The effect of acute treatment with psychostimulants on behaviour and modelling of judgement bias. Amphetamine (0.1, 0.3 mg/kg) or cocaine (0.3, 1.0, 3.0 mg/kg) or saline vehicle (0.0 mg/kg) were administered acutely prior to testing on the judgement bias task. (A/E) Amphetamine (0.3 mg/kg) induced a positive judgement bias, whilst cocaine had no effect. (B/C/D) As with the positive bias induced acutely by ketamine, diffusion modelling indicated a more positive drift rate was also underlying the positive bias induced by amphetamine. Amphetamine had no effect on other model parameters. (F/G/H) Cocaine did not alter any diffusion model parameters. Data shown are for the midpoint tone only, and represent mean±SEM. Amphetamine: n=15, 15 min pre-treatment; cocaine: n=17, 10 min pre-treatment. **p<0.01.