Delaying reward feedback does not increase the influence of information on attentional priority in visual search

Demonstrations of information-seeking behaviour suggest that attention often acts in an exploitative way, prioritising stimuli that provide diagnostic information about upcoming events over stimuli associated with uncertainty. However, recent evidence from studies of attentional capture in visual search show an opposite pattern: automatic prioritisation of items associated with reward uncertainty over diagnostic stimuli. We hypothesise that this uncertainty-modulated attentional capture (UMAC) effect reflects 'attention for learning': that is, exploration of potential sources of new information. Here we investigated whether UMAC arises because immediate provision of reward feedback in prior studies rendered advance information redundant, attenuating exploitation of diagnostic items and promoting exploration. Accordingly, increasing the duration of anticipated uncertainty (and hence the value of advance information that allows us to escape uncertainty earlier) should promote prioritisation of diagnostic cues and lead to patterns of attentional exploitation. In two eye-tracking experiments, we compared attentional capture by a cue providing diagnostic reward information and a cue signalling uncertain reward, while manipulating the delay between response and feedback (i.e., the duration of anticipated uncertainty that advance information could forestall). We found a UMAC effect in all conditions: regardless of response-feedback delay, uncertain stimuli were more likely to capture attention than diagnostic stimuli. These results suggest that prioritisation of uncertainty is a robust pattern of behaviour in this task. Synthesising current and previous findings, we suggest that different modes of attentional information-seeking may reflect qualitative task differences, with exploration operating at an implicit, automatic level, and exploitation resulting from top-down, volitional processes.