Neural correlates of inference-driven attention in perceptual and symbolic tasks: An event-related potential study

The inferential system anticipates the external environment by building up internal representations of
its regularities. To that purpose, two sources of information are especially important and attract attentional
resources: expected and unexpected events, which are useful for checking the accuracy of internal
representations. In the present study, we investigated the behavioural properties and the neural mechanisms
underlying the strategic allocation of attention triggered by those events. To that end, eventrelated
potentials (ERPs) were recorded during the performance of two tasks requiring detection of
predictable and unpredictable response events embedded in a visuospatial or numeric sequence. The
behavioural results in the two tasks mirror each other, suggesting the recruitment of similar attentional
allocation processes between the two domains. The ERPs showed partially similar effects. In both
tasks, a P3a-like component signalled the capture of attention by events clashing with previous expectations,
whilst a P3b-like component marked the focusing of attention on predicted events and its
redistribution among all possible response events occurring after the detection of an unexpected event