A Neural Indicator of Response Competition in Preferential Choice

Contemporary theories of decision-making often seek to specify the emotional, motivational, and cognitive processes that underlie observable decision behaviors. This requires us as researchers to pursue more sophisticated means of empirically verifying hypothesized processes. To that end, we present 3 experiments that used the lateralized readiness potential (LRP) to establish a neurological basis for response competition in decisions involving subjective preferences. Affectively valenced pictures and monetary gambles were used as stimuli in binary decision tasks in Experiment 1 and 2, respectively. The results of Experiment 1 provide evidence that the LRP is capable of measuring preparatory motor activity underlying the dynamic accumulation of subjective preference in the premotor cortex. Neural signatures indicated there was more response competition when participants chose between more similar stimuli (affective valence) as indicated by the neural signatures. When choosing among gambles in Experiment 2, we again observed increased response competition when participants chose between more similar stimuli (risk). Experiment 3 served to reinforce the findings of Experiment 2 using a similar experimental setup with gamble stimuli counterbalanced based on a different metric for risk.