Attention capture: Stimulus, group, individual, and moment-to-moment factors contributing to distraction
Over four studies, some containing multiple experiments, attention capture is explored in a variety of experimental contexts. The over-arching goals were to better understand attention capture at the stimulus level (Chapter 2), the group and the individual-differences level (Chapters 3 and 4), and in terms of moment-to-moment fluctuations in susceptibility to distraction by task-irrelevant stimuli (Chapter 5). Rare or unexpected stimulus changes are known to capture attention and disrupt behavioural performance. Detection is typically thought to depend on changes to the physical properties (e.g., tone pitch) of a stimulus. Chapter 2 explores whether physical change is a necessary antecedent for attention capture. Here, evidence suggests that unexpected semantic change is sufficient to produce a distraction effect and that an accompanying physical/acoustic change is not required to induce semantic processing of task-irrelevant stimuli even when the semantic deviants are unrelated to the primary task. Attention capture is typically robust at the group level and has been observed in a variety of popular paradigms. Chapter 3 explores whether attention capture can be viewed as a stable and generalizable individual trait. The study examined involuntary attention capture across a set of prototypical stimulus-driven capture tasks and contingent-capture tasks in both spatial and/or temporal paradigms. Results showed the expected pattern of capture in each of the tasks as well as modest to good test-retest reliability over the span of one week for each of the capture measures. However, no evidence is found for a common attention capture factor providing evidence that attention capture within an individual is reliable but not generalizable. Chapter 4 extends the results of Chapter 3 and shows that attention capture in these tasks is not related to off-line self-report measures of attentional ability and day-to-day functioning. The lack of evidence for a common factor that can predict attention capture in one or more paradigms suggests that attention capture is not characterized by trait individual differences in executive function or predicted by individuals’ meta-awareness of their own attentional ability. Chapter 5, however, shows that attention capture can be characterized by moment-to-moment lapses of attention as it varies trial-to-trial as a function of internally generated task-irrelevant thought (i.e., mind-wandering). Mind-wandering slowed RTs overall and increased non-contingent, but not contingent, forms of capture providing evidence that some forms of attention capture are exacerbated by moment-to-moment lapses of attention. Self-reports on a dispositional mind-wandering scale did not predict capture when mind-wandering was used as an individual differences variable. Results suggest that attention capture may be better explained by cognitive processes engaged moment-to-moment rather than individual dispositions.