Motivational Salience Signal in the Basal Forebrain Is Coupled with Faster and More Precise Decision Speed
Figure 1
(A) Schematic of the reward-biased simple RT task. Rats initiated each trial by nosepoking in a fixation port following a trial start light signal. Inside the fixation port, three trial types—S-Large, S-Small, and Catch—were presented with equal probability and respectively associated with a large, small, or no reward in the adjacent port. RT was defined as the time between sound onset and fixation port exit. (B) Scatter plot of the mean RT in S-Large versus S-Small trials. Each dot represents one session from one rat (n = 339, 16 rats). Inset shows the overall mean ± sem (paired t test). (C) RT modulation as a ratio of mean RT between S-Large versus S-Small trials in each session around the reversal learning transition. Seventeen individual transition sequences (gray lines) with at least five sessions both before and after reversal learning were plotted, with the overall mean ± sem in black. In the first three sessions after the reversal learning transition, RT was faster toward S-Small, which predicted the larger reward before reversal. The RT difference grew larger with more training, and did not reach asymptotic level after 10 sessions.