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Seminar: 3/6 - Edward Vogel

11:00 to 12:30 PM      at:  5101 Tolman Hall

Department of Psychology, University of Oregon
"Individual differences in resisting attentional capture."

The storage capacity of visual short-term memory (VSTM) for simple objects is known to be severely restricted and to vary considerably across individuals. Individual differences in memory capacity appear to be a stable trait of the observer and are positively correlated with many high-level aptitude measures such as fluid intelligence and reasoning.These individual differences in capacity have often been proposed to be due to variability in memory storage space. However, it is also possible that much of the variability stems from the efficiency of attentional control mechanisms that restrict access to VSTM. In previous experiments, we have found the low capacity subjects are poorer at keeping irrelevant items from being stored in VSTM than high capacity subjects. In the present study, we extend these findings by examining individual differences in the initial allocation of spatial attention towards target and distractor onsets. Here we found that when targets were presented in isolation all subjects showed equivalent attentional modulations of early visually-evoked neural responses. However, when the target was accompanied by distractors, large differences across individuals were observed; while high capacity subjects maintained a tight focus upon the target location, the low capacity subjects involuntarily reallocated attentional focus to also include the distractor locations. These results suggest that individual differences in VSTM may stem from variability in resisting attentional capture by the initial onsets of irrelevant objects.