Effects of instructed and experienced uncertainty on attentional priority

Previous research has demonstrated that attentional prioritisation is shaped by prior experience of reward uncertainty: attention is more likely to be captured by a stimulus associated with a variable (uncertain) reward than a stimulus that provides diagnostic information about available reward. This finding is noteworthy, because it runs counter to the principle that cognition is motivated to reduce uncertainty and hence surprise. Here we investigated whether this pattern of uncertainty-modulated attentional capture (UMAC) reflects a process of attention for learning, wherein uncertainty-related stimuli are prioritised in an attempt to learn about their true predictive status. To address this, we examined the distinct impact of two information sources that modulate potential for learning; explicit instruction versus ongoing experience of prediction error in reward feedback. Experiment 1 demonstrated that providing explicit instructions—and hence negating the need for further learning—did not reduce the magnitude of the UMAC effect, indicating that UMAC does not reflect attention for learning as a strategic approach for determining the task state. On the other hand, Experiment 2 showed that instructions alone were insufficient to generate a UMAC effect in the absence of reward feedback, suggesting that the impact of uncertainty on rapid attentional prioritisation is driven by direct experience of prediction error. Taken together, these findings point to two possibilities: UMAC may reflect attention for learning operating at an implicit level, or may evince an attentional system that is configured for rapid detection of sources of experienced uncertainty so that subsequent behaviour can be tailored appropriately.