title: Dynamics of task-set carry-over: evidence from eye-movement analyses.
abstract: Trial-to-trial carry-over of task sets (i.e., task-set inertia) is often considered as a primary reason for task-switch costs. Yet, we know little about the dynamics of such carry-over effects, in particular how much they are driven by the most recent trial rather than characterized by a more continuous memory gradient. Using eye-tracking, we examined in a 3-task, switching paradigm whether there is a greater probability of non-target fixations to stimuli associated with the previously relevant attentional set than to those associated with the less-recent set. Indeed, we found strong evidence for more interference (expressed in terms of non-target fixations) from recent than from less-recent tasks and that in particular the interference from pre-switch trials contributed substantially to the overall pattern of response-time switch costs. Moreover, task-set carry-over was dominated by the most-recent trial when subjects could expect task repetitions (with a 33 % switch rate). In comparison, when tasks were selected randomly (with a 66 % switch rate), interference from the most recent trial decreased, whereas interference from less-recent trials increased. In sum, carry-over interference dynamics were characterized both by a gradual recency gradient and expectations about task-transition probabilities. Beyond that, there was little evidence for a unique role of the most-recent trial.
authors.affiliation: Department of Psychology, University of Oregon, Eugene, OR, 97403, USA.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kikumoto
authors.affiliation: Department of Psychology, University of Oregon, Eugene, OR, 97403, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Hubbard
authors.affiliation: Department of Psychology, University of Oregon, Eugene, OR, 97403, USA. mayr@uoregon.edu.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mayr
mesh_terms: D001288:Attention; D003071:Cognition; D053483:Eye Movement Measurements; D005133:Eye Movements; D006801:Humans; D011897:Random Allocation; D011930:Reaction Time; D013647:Task Performance and Analysis
keywords: Cognitive control; Task switching