A multiple-choice task with changes of mind

Abstract

The role of changes of mind and multiple choices has recently received increased attention in the study of perceptual/ndecision-making. Previously, these extensions to standard two-alternative tasks have been studied separately. Here we/nexplored how changes of mind depend on the number of choice-alternatives. To this end, we tested 14 human subjects on/na 2- and 4-alternative direction-discrimination task. Changes of mind in the participants’ movement trajectories could be/nobserved for two and for four choice alternatives. With fewer alternatives, participants responded faster and more/naccurately. The frequency of changes of mind, however, did not significantly differ for the different numbers of choice/nalternatives. Nevertheless, mind-changing improved the participants’ final performance, particularly for intermediate/ndifficulty levels, in both experimental conditions. Moreover, the mean reaction times of individual participants were/nnegatively correlated with their overall tendency to make changes of mind. We further reproduced these findings with a/nmulti-alternative attractor model for decision-making, while a simple race model could not account for the experimental/ndata. Our experiment, combined with the theoretical models allowed us to shed light on: (1) the differences in choice/nbehavior between two and four alternatives, (2) the differences between the data of our human subjects and previous/nmonkey data, (3) individual differences between participants, and (4) the inhibitory interaction between neural/nrepresentations of choice alternatives.