Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.05.01.072264v1?rss=1 Authors: Tal-Perry, N., Yuval-Greenberg, S. Abstract: A series of recent studies suggested that eye movements are linked to temporal predictability. In these studies, temporal predictability was manipulated by setting the interval between a cue and a target (foreperiod) to be either fixed or random, in separate blocks. Findings showed that shortly prior to target onset, oculomotor behavior was reduced in the fixed relative to the random condition. This effect was interpreted as reflecting the formation of temporal expectation. However, it is still unknown whether the effect is driven by target-specific temporal orienting (orienting hypothesis), or whether it is a result of a more general and context-dependent state of certainty that participants may experience during blocks with a high predictability rate (certainty hypothesis). In the following study we examined this question by dissociating certainty and orienting. In each trial, a temporal cue (fixation color change) was followed by a slightly tilted grating-patch, on which participants made tilt-discrimination decision. The distribution of the foreperiods was varied between blocks to be either fully fixed (100% of trials with the same foreperiod), mostly fixed (80% of trials with one foreperiod and 20% with another) or random (five foreperiods in equal probabilities). The two hypotheses led to different prediction models which were tested against the experimental data. Results were highly consistent with the orienting hypothesis and inconsistent with the certainty hypothesis, supporting the link between oculomotor inhibition and temporal orienting and its validity as a marker for target-specific expectations in future studies. Copy rights belong to original authors. Visit the link for more info