Prominent models of attentional control assert a dichotomy between top-down and bottom-up control, with the former determined by current selection goals and the latter determined by physical salience. This theoretical dichotomy, however, fails to explain a growing number of cases in which neither current goals nor physical salience can account for strong selection biases. For example, equally salient stimuli associated with reward can capture attention, even when this contradicts current selection goals. Thus, although ‘top-down’ sources of bias are sometimes defined as those that are not due to physical salience, this conception conflates distinct – and sometimes contradictory – sources of selection bias. We describe an alternative framework, in which past selection history is integrated with current goals and physical salience to shape an integrated priority map.

It is well known that salient yet task irrelevant stimuli may capture our eyes independent of our goals and intentions. The present study shows that a task-irrelevant stimulus that is previously associated with high monetary reward captures the eyes much stronger than that very same stimulus when previously associated with low monetary reward. We conclude that reward changes the salience of a stimulus such that a stimulus that is associated with high reward becomes more pertinent and therefore captures the eyes above and beyond its physical salience. Because the stimulus capture the eyes and disrupts goal-directed behavior we argue that this effect is automatic not driven by strategic, top-down control.

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In the present study, we explored the mechanisms involved in the contingent capture phenomenon, using a variant of the classic precuing paradigm of Folk, Remington, and Johnston (1992). Rather than keeping the target fixed over a whole block of trials (as has traditionally been done with contingent capture experiments), we encouraged participants to adopt a top-down set before each trial. If top-down attentional set determines which property captures attention, as is claimed by the contingent capture hypothesis, one would expect that only properties that match the top-down set would capture attention. We showed that even though participants knew what the target would be on the upcoming trial, both relevant and irrelevant properties captured attention (Experiment 1). An intertrial analysis (Experiments 1 and 2) showed that previous contingent capture findings may, to a large extent, be explained by intertrial priming. In addition, when participants were further forced into adopting the required top-down set (Experiments 3 and 4), irrelevant cues were suppressed, suggesting that top-down control might operate through disengagement of attention from the location of a property that does not match top-down goals. The present findings suggest that top-down control and intertrial priming make their own distinct contributions to the contingent capture phenomenon.

Performance deteriorates when subjects must shift between two different tasks relative to performing either task separately. This switching cost is thought to result from executive processes that are not inherent to the component operations of either task when performed alone. Medial and dorsolateral frontal cortices are theorized to subserve these executive processes. Here we show that larger areas of activation were seen in dorsolateral and medial frontal cortex in both younger and older adults during switching than repeating conditions, confirming the role of these frontal brain regions in executive processes. Younger subjects activated these medial and dorsolateral frontal cortices only when switching between tasks; in contrast, older subjects recruited similar frontal regions while performing the tasks in isolation as well as alternating between them. Older adults recruit medial and dorsolateral frontal areas, and the processes computed by these areas, even when no such demands are intrinsic to the current task conditions. This neural recruitment may be useful in offsetting the declines in cognitive function associated with ageing.

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Attention can be captured automatically by events that are physically salient. Similarly, emotional stimuli are known to be prioritised by the visual system because of their behavioural significance. The present study investigated whether a neutral stimulus which became associated with fear captured attention in visual search. Using a fear-conditioning procedure, one stimulus was repeatedly combined with an electrical shock (CS+), whereas another stimulus with identical physical features was never combined with a shock (CS-). Following conditioning, participants had to search for a target; while on some trials, either an irrelevant CS+ or CS- stimulus was present. The results show that the presence of an irrelevant distractor that was previously associated with fear slowed a search more than a distractor without fear association. The current results indicate that learned fear associations have the ability to capture our attention even if we try to ignore them.