"Save the worst for last": Strategies for choosing movement options in a sequential task


Previous research has revealed that when actors select and complete only 1 of 2 movement options (Task-A OR Task-B), rational decision-makers choose the task with the maximum expected gain (MEG). The present study was designed to assess factors that affect choosing the order of to-be-completed tasks when actors must perform one task and then the other task (Task-A THEN Task-B). Participants were presented with 2 target-penalty configurations in which a target circle was partially overlapped by an equivalently sized penalty circle. Configurations varied in the value of the penalty region and the amount of overlap (a spatial property related to the probability of contacting the target and/or penalty region) such that the configurations could have similar or different MEGs. Participants imagined sequentially performing aiming movements to both target-penalty configurations, one after another, and indicated which of the two they imagined aiming to first. Whenever the MEGs of the two options differed, participants indicated that they would aim to the configuration with the higher MEG first more often than the lower MEG. When configurations had similar MEGs but differed in penalty and spatial parameters, there were no consistent strategies in choice at the group level, though individual strategies were noted – some participants emphasized penalty and others emphasized space. Overall, the data suggests that when presented with a sequential task, participants would first perform the task that maximizes gain and that individuals have strategies that differentially weigh spatial and penalty parameters when differences in gain are not apparent.

Acknowledgments: This research was supported by grants and scholarships from NSERC