Oculomotor inhibition precedes temporally expected auditory targets

Abstract

28Eye movements are inhibited prior to the onset of temporally-predictable visual targets. This 29 oculomotor inhibition effect could be considered a marker for the formation of temporal 30 expectations and the allocation of temporal attention in the visual domain. Here we show 31 that eye movements are also inhibited before predictable auditory targets. In two 32 experiments, we manipulate the period between a cue and an auditory target to be either 33 predictable or unpredictable. The findings show that although there is no perceptual gain 34 from avoiding gaze-shifts in this procedure, saccades and blinks are inhibited prior to 35 predictable relative to unpredictable auditory targets. These findings show that oculomotor 36 inhibition occurs prior auditory targets. This link between auditory expectation and 37 oculomotor behavior, in combination with the results of our parallel study in the tactile 38 domain, reveals a multimodal perception action coupling, which has a central role in temporal 39 expectations. 40 41 100 asked to perform a 2-alternative forced choice (2AFC) discrimination task: report whether the chirp was 101 ascending or descending by pressing one of two buttons. Participants were instructed to be as accurate as 102 possible and to respond within the 4 seconds response window. Following the response, or after 4 s without 103 one, the fixation-cross changed color to gray for 200 ms to signal the end of the trial. B) The foreperiod was 104 either constant throughout the block (predictable condition) or changed randomly in different trials within the 105 same block (unpredictable condition). Thus, the cue acted as a 100% valid temporal cue in the predictable 106 condition but was uninformative regarding target timing in the unpredictable condition. The stimuli were 107 identical in the two conditions, and differed only in the validity of the temporal cue in predicting the time of the 108 target. Participants were not informed as to any predictability; therefore, all temporal expectations were 109 4 learned incidentally. 110 111 Results 112Behavioral performance: accuracy-rates and reaction times 113Accuracy-rates and reaction times (RT) were calculated separately for each participant, 114 condition and foreperiod. A two-way repeated measures ANOVA with factors Predictability 115 (predictable/unpredictable) and Foreperiod (1, 1.5, 2, 2.5, 3 s) revealed no evidence for 116 differences in accuracy-rates between predictability conditions (F(1,19) = 1.62, p = 0.22) or 117 foreperiods (F(4,76) = 0.81, p = 0.52), and no significant interaction between these two factors 118 (F(4,76) = 0.39, p = 0.746). The same analysis performed on RT of correct trials (secondary 119 variable) revealed a significant main effect of foreperiod (F(4,76) = 4.83, p = 0.006, ε = 0.708, 120 130 (blue bars) conditions. Error bars denote ± one standard error of the mean, corrected for within subjects 131 variability 13 . Source data are provided as a Source Data file. 133Saccades 134

Pre-target oculomotor inhibition reflects temporal orienting rather than certainty

“…The present study is an important step in strengthening this conclusion. The present findings provide a replication for the previously-reported effects [2][3][4][5][6]. As in previous studies, we found that: (a) slightly prior to target onset, saccade rate is lower (i.e.…”

“…In a series of previous studies it has been suggested that pre-target oculomotor inhibition could be an informative measurement for assessing target predictability [2][3][4][5][6].…”

“…This oculomotor inhibition phenomenon can be used as a sensitive marker for temporal expectation and, as such, has several advantages over traditional behavioral and electrophysiological markers [2]. In our previous studies, we found that oculomotor inhibition prior to a predictable target occurs with various types of temporal structures: with rhythmic expectations, when stimuli were predictable because they are part of a rhythmic stream of stimulation [3], and with associative expectations, when targets are rendered predictable by a precedent informative temporal cue in a visual [2], auditory [5] or tactile [6] task. Oculomotor inhibition was also hypothesized to be modulated by conditional expectationsexpectations that gradually increase as time progresses and an expected event has not yet occurred [2].…”

“…Temporal expectation is a prediction regarding the timing of events based on previously-experienced temporal regularities [1]. Recent studies showed that the oculomotor system is tightly linked to temporal attention and expectation: oculomotor activity (saccades, ocular drift, and blinks) is inhibited for a few hundred milliseconds prior to the appearance of a predictable, relative to an unpredictable, stimulus [2][3][4][5][6]. This oculomotor inhibition phenomenon can be used as a sensitive marker for temporal expectation and, as such, has several advantages over traditional behavioral and electrophysiological markers [2].…”

“…In our previous studies on oculomotor inhibition, temporal expectation was manipulated by modulating the foreperiod -the time period between a predicting event (e.g. the onset of a temporal cue or the previous stimulus in a stream) and target onset [2,3,5,6]. In these studies, we included two conditions: (a) a fixed condition, in which the forepriod was identical for all trials, rendering the target predictable and (b) a random condition, in which it varied between a few options, rendering the target less predictable.…”