Behavioural and electrophysiological investigations of individual differences in dual-task attention costs

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In our daily lives we often perform two tasks at once, or try to attend to more than one thing at a time (for example, talking on a cell phone while driving). Our desire to multi-task often conflicts with the fact that there are limits on how much information we can attend to at any given time. When we perform two attention-demanding tasks at the same time, performance on one or both tasks often suffers. To investigate multi-tasking difficulties, in my lab visual stimuli such as letters are presented in rapid succession in the same location on the computer screen. Two targets are presented as part of the stream of information, and the time interval between these two targets varies from less than one-tenth of a second to almost two seconds. Participants are asked to report both of the targets. Behavioural response accuracy to target 1 and target 2 are measured. Responses to target 2 show a marked decreased in accuracy when targets are presented closely together in time - a phenomenon known as the attentional blink (AB). Recent research has shown that the size of the AB differs across individuals, but is relatively stable across time for the same individual. Recent work from my lab has shown that individual differences in the size of the AB are predicted by various dispositional, brain-wave, and cognitive performance measures. I suggest that individual differences in AB size result from individual differences in attentional focus and investment, as modulated by anterior cingulate cortex driven performance monitoring. The goal of the proposed research is to record both brain and behavioural measures and to use an individual differences approach to test this conceptualization in a series of research projects. This innovative individual differences approach to understanding AB, combined with the use of physiological measures, will help us understand why some individuals are better able to overcome dual-task attention costs than others. This will not only provide insight into the underlying nature of the AB, but may help us arrive at insights into human attentional processing modulations that may be difficult to achieve using other approaches. This knowledge may help us to lead to successful strategies for reducing these costs in our daily life.