Duyar, A. | Search bioRxiv

bioRxiv2024

Eyes on the past: Gaze stability differs between temporal expectation and temporal attention

Temporal expectation and temporal attention distinctly improve performance and gaze stability, and interact at the behavioral and neural levels. Foreperiod--the interval between the preparatory signal and stimulus onset--facilitates temporal expectation. Preceding foreperiod--the foreperiod in the previous trial--modulates expectation at behavioral and oculomotor levels. Here, we investigated whether preceding foreperiod guides temporal attention. Regardless of the preceding foreperiod, temporal attention improved performance, particularly at early moments,and consistently accelerated gaze stability onset and offset by shifting microsaccade timing. However, only with preceding expected foreperiods, attention inhibited microsaccade rates. Moreover, preceding late foreperiods weakened expectation effects on microsaccade rates, but such a weakening was overridden by attention. Altogether, these findings reveal that the oculomotor systems flexibility does not translate to performance, and suggest that although selection history can be utilized as one of the sources of expectation in subsequent trials, it does not necessarily determine, strengthen, or guide attentional deployment.

neuroscience↗

bioRxiv2023

When to attend? Temporal attention interacts with expectation

Temporal attention is voluntarily deployed at specific moments, whereas temporal expectation is deployed according to timing probabilities. When the target appears at an expected moment in a sequence, temporal attention improves performance at the attended moments, but the timing and the precision of the attentional window remain unknown. Here we independently and concurrently manipulated temporal attention-via behavioral relevance-and temporal expectation-via session-wise precision and trial-wise hazard rate-to investigate whether and how these mechanisms interact to improve perception. Our results reveal that temporal attention interacts with temporal expectation-the higher the precision, the stronger the attention benefit, but surprisingly this benefit decreased with delayed onset despite the increasing probability of stimulus appearance. When attention was suboptimally deployed to earlier than expected moments, it could not be reoriented to a later time point. These findings provide evidence that temporal attention and temporal expectation are different mechanisms, and highlight their interplay in optimizing visual performance. RelevanceOur ability to process visual information is limited both across space and time. Here we disentangle how two mechanisms-attention and expectation-help us overcome temporal limitations. We concurrently manipulated attention and expectation independently to investigate whether and how they interact. We found that temporal attention interacts with two distinct forms of expectation. Temporal expectation strengthens the benefits of temporal attention on performance for the attended time points, depending on how precise the expectations are. Surprisingly, the advantages of attention decrease when stimuli occur later than expected, suggesting a limitation of attention to reorient from earlier to later time points. This study provides further evidence that humans cannot sustain temporal attention even over short periods, reveals that although temporal attention and expectation interact to improve visual performance, expectation suboptimally guides attention, and highlights that attention and expectation are different temporal mechanisms.

neuroscience↗