Response times (RTs) were shorter in trials with potential reward (M = 514.96 ms, SD = 50.69 ms) versus those without (M = 526.28 ms, SD = 54.43 ms), as indicated by a main effect of reward (F(1,21)=22.81, p<0.001, see table 1). There was also a significant main effect of task difficulty (F(1,21)=109.36, p<0.001) with faster responses for low-difficulty trials (M = 491.29 ms, SD = 50.13 ms) than for high-difficulty trials (M = 549.95 ms, SD = 57.47 ms). The interaction of reward and task difficulty approached significance (F(1,21)=4.02, p=0.058) explained by a larger RT difference between high-difficulty and low-difficulty trials for reward trials compared to no-reward trials.
