Figure 4.

Behavioral performance in the two-delay version of the simple RT task following muscimol inactivation of RFA. (A) Task design: Rats pressed a lever down to initiate a trial and this initiated either a short (0.6 s) or long (1.2 s) delay period. See section “Materials and methods” for details. (B) Approximate locations of cannula tips at sites where intracranial microstimulation elicited discrete forelimb movements. Images adapted from Paxinos and Watson (1998). (C) Rats (n = 7) with unilateral infusions of muscimol (0.5 μl of 1.0 μg/μl into one hemisphere) did not make more premature responses at either the short or the long delays. There was increased premature responding at longer delays compared to shorter delays (rmANOVA: P < 0.01). (D) Geometric mean RTs (error bars representing geometric absolute deviation) were significantly longer at short compared to long delays under saline (*P < 0.05, paired t-test), but was no significant difference in RTs after the shorter and longer delays with muscimol in RFA (P > 0.05, paired t-test).