Rate dependent Effects of AMPH on attentional processes as measured by 5C-CPT task

The study investigates the impact of amphetamine (AMPH) on attentional processes in rat 5C-CPT task, with an emphasis on the rate dependency of its effects. The researchers tested female Lister hooded rats with AMPH doses of 0.1, 0.2, and 0.4 mg/kg under varying stimulus duration schedules (0.25, 0.5, 1, 1.5, and 2 seconds) to evaluate the drug's influence on sustained attention.

The results revealed that the highest dose of AMPH impaired attentional performance in the 5C-CPT when the stimulus duration was reduced, leading to an increase in false alarm rate (FAR). This impairment was due to the increased attentional demands imposed by the shorter stimulus duration, as the task required more sustained attention and responsivity index than the 5-CSRTT, which lacks non-target trials.

The study found that the highest dose of AMPH (0.4 mg/kg) had a tendency to reduce sensitivity index (sensitivity to changes in stimulus duration) under 0.5, 1.0, and 1.5 seconds stimulus durations. At 1.0 seconds stimulus duration, the highest dose of AMPH (0.4 mg/kg) showed a rate-dependent impairment in sustained attention (sensitivity index, hit rate, false alarm rate, and omission rate) without changing the responsivity index.

The study also noted an inverse relationship between baseline accuracy and the change following administration of 0.2 mg/kg AMPH, indicating a rate-dependent effect. This research demonstrates a rate-dependent effect of AMPH on attentional performance in the 5C-CPT and highlights responsivity index as a sensitive measure to reduced stimulus duration challenges.