Abstract choice representations during stable choice-response associations
Perceptual decisions have long been framed in terms of the actions used to report a choice. Accordingly, studies of perceptual decision-making have historically relied on tasks with fixed choice-response mappings, in which choice and motor response are inextricably linked. Although several studies have since dissociated choice and response, they have typically involved dynamic switching of the choice-response mapping on a trial-by-trial basis. Thus, it remains unclear if abstract choice representations arise specifically when choice-response relationships change dynamically, or if they reflect a more general property of the decision-making process. Here, we show that in the human brain, choices are represented abstractly, even when the association between choice and motor response remains stable over time. We measured neural activity in humans using magnetoencephalography (MEG) while participants performed a motion discrimination task. Importantly, the associations between perceptual choice and motor response were balanced across experimental conditions and remained stable over many trials. We found neural information about the participants perceptual choice, independent of both the motor response and the visual stimulus. This abstract choice information increased during the stimulus period and peaked after the response had been made. Furthermore, choice and response information showed distinct cortical distributions, with strongest choice information in frontoparietal regions. Our results suggest that abstract choice representations are not restricted to action-independent contexts or those with dynamic choice-response associations and may therefore reflect a general role in perceptual decision-making.