Abstract
Individuals differ considerably in the degree to which they benefit from attention allocation. This includes both benefits (i.e., better performance when the target appears at a cued than a non-cued location) and costs (i.e., worse performance when the target appears at an invalidly cued than a non-cued location), and with different tasks. Thus far, such individual differences were attributed to post-perceptual factors such as working-memory capacity. Here, we examined whether a perceptual factor – the level of internal noise – is related to inter-individual variability in attentional effects. To that end, we estimated observers’ internal noise using the double-pass procedure combined with an external noise paradigm, and the perceptual template model. We also measured the effects of spatial attention in an acuity task: the participants reported the side of a square on which a small aperture appeared. Central arrows were used to engage sustained attention and peripheral cues to engage transient attention. Additionally, we measured temporal attention using the attentional blink paradigm. We found reliable correlations between individual levels of internal noise and the effects of both types of spatial attention, albeit of opposite directions: positive correlation with sustained attention and negative correlation with transient attention. When participants were split into groups by internal noise level (low/high), we found that participants with high internal noise displayed a significant cost of attending the wrong location when deploying sustained attention. Regarding the attentional blink, we found that internal noise predicted lag-1 cost. Taken together these findings demonstrate that internal noise – a fundamental characteristic of visual perception – can predict individual differences in the effects of various types of attention. We speculate that internal noise might be related to increased attention-related inhibitory processes, such that individuals with high levels of internal noise might demonstrate increased levels of attention-related inhibition.