Abstract
Fluctuations in preparatory cognitive control have important behavioral consequences for goal-directed attentional selection. In particular, the speed with which individuals update selections varies according to preparatory control settings. We tested whether the statistical properties of an environment persistently modulated preparatory states of attentional control. In each of three experiments, participants held and shifted attention between two rapid serial visual presentation streams of alphanumeric characters in response to visual cues. Behavioral response times (RT) to target stimuli immediately following a cue provided an index of attentional flexibility. In Experiment 1, we varied the frequency of shift and hold cues across time during a training phase. Shift costs were smaller at intervals when shift cues were frequent, suggesting that control settings were modulated according to the statistical structure. In a subsequent test phase, we presented both cue types with equal frequencies across time. We found minimal transfer of control states after this switch in cue probabilities. In Experiment 2, we manipulated the frequency of shift and hold cues in separate blocks of stimuli. In further support of statistical learning, shift costs varied based on cue probabilities across contexts and this RT difference persisted throughout a subsequent test phase in which both cue types were equally likely. Lastly, in Experiment 3, we paired the temporal and contextual manipulations of the first two experiments. Cue probabilities varied across time as in Experiment 1, but critically, stimulus color predicted which of two opposing probability structures was in effect on a trial-by-trial basis. Unlike the first two experiments, we found no evidence of learning-based modulations of cognitive control for this more complex statistical structure. Taken together, our findings provide evidence that the statistical properties of an environment play an important role in guiding the flexible deployment of attention.
Meeting abstract presented at VSS 2014