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Motor and perceptual aspects of temporal expectation.

Sunday, October 02nd,   2011 [11:30 - 13:10]

SY_31. Motor and perceptual aspects of temporal expectation

Thomaschke, R.

Institut für Psychologie. Universität Regensburg. Regensburg. Germany.

It is a well established finding that temporal expectation facilitates a wide range of cognitive processes, from early stimulus perception to late motor-levels. It is, however, still under debate, which underlying mechanisms are responsible for temporal expectation and its behavioral effects. The symposium brings together five accounts of temporal expectation, which address the phenomenon each from a different experimental perspective. The symposium has two main emphases. One is on integrating results from different experimental designs. For example, recent research has shown that auditory attention is differently affected by temporal expectation, depending on the experimental context. In the symposium, electrophysiological effects of inducing auditory temporal expectation in different way by rhythms, or by constant foreperiods, are discussed, and compared with related temporal expectation effects on visual perception. A second emphasis of the symposium is on showing how new results from temporal expectation research can fruitfully inform theorizing on classical response-time paradigms, like attentional cuing, and cross modal integration, which has previously largely neglected the temporal dimension.



SY_31.1 - Motor and perceptual aspects of temporal expectancy: Identifying classic confounds in attention research

Boulinguez, P.

Centre de Neuroscience Cognitive, UMR CNRS 5229 & Université Claude Bernard Lyon 1, France

Questions about attention are usually addressed by cueing tasks assessing whether knowledge of stimulus-related information provided in advance will improve target processing. However, growing evidence suggests that inhibitory control of response is critically involved in such tasks. This control operates in anticipation of stimulus arrival and acts as a gating mechanism intended to withhold automatic responses to visual stimuli in order to prevent false alarms (responses to cues). As a consequence, behavioural and physiological baselines classically used to refer cue-related changes in attention research using standard cue-target detection protocols are biased and multiple cue-induced effects are potentially confounded. Here, I will review EEG, fMRI, behavioural and clinical data in humans revealing this widespread bias, and propose methodological refinements of standard protocols that allow disentangling executive control mechanisms from motor, perceptual and attentional processes.

SY_31.2 - Limits to multisensory integration - a case for temporal preparation

Los, S. A. & Van der Burg, E.

VU University, Amsterdam, Netherlands

A well known finding in the human reaction time (RT) literature is that an irrelevant auditory stimulus (S1) reduces RT for a simultaneous visual target stimulus (S2). Two explanations have been offered for this finding: (1) the information of the visual and auditory senses merge to yield a stronger percept than when the visual stimulus is presented alone (i.e., multisensory integration); (2) the auditory S1 arrives earlier at a central level than the visual S2 and initiates a preparation process that reduces RT (i.e., temporal preparation). Starting from the temporal preparation explanation, we devised a procedure that allowed us to estimate the effective preparation period (EPP) - the interval between S1 and S2 corrected for differences in their central arrival times. In addition, we manipulated the stimulus onset asynchrony (SOA) between S1 and S2 (0 - 400 ms) in conjunction with the modality of S1. When expressed as a function of SOA, we observed a substantial effect of S1 modality on RT. However, this effect disappeared completely after re-expressing RT as a function of EPP. This finding strongly supports the temporal preparation explanation.

SY_31.3 - Temporal expectancy shortens the onset of perceptual processes

Seibold, V. C. , Bausenhart, K. M. & Rolke, B.

Eberhard Karls Unversität Tübingen, Tübingen, Germany

Over the past ten years, a variety of studies have shown that temporally expecting a stimulus facilitates perceptual processing. To investigate the possible mechanisms underlying this perceptual benefit, we conducted two studies. In the first study, we used speed-accuracy-tradeoff (SAT) functions to assess whether temporal expectancy affects the dynamics of perceptual processing. Specifically, we used a spatial discrimination task in which participants had to judge whether the upper line of a cross was longer or shorter then the other ones. The time available for target processing was varied by presenting a response signal with a variable delay after target onset, and temporal expectancy for targets was manipulated via constant foreperiods. The obtained SAT functions suggest that temporal expectancy acts on the onset of perceptual processes. In the second study, we aimed to find possible neuronal markers for this onset effect by means of sensory event-related potentials (ERPs). Specifically, we used an auditory oddball task in which participants had to detect infrequent target tones intermixed in frequent standard and infrequent deviant tones. Temporal expectancy was again manipulated via constant foreperiods. We observed that the latencies of sensory ERPs, i.e. the N1 and the N2 difference wave, were shortened in conditions of high temporal expectancy. Taken together, the two studies provide first evidence that temporal expectancy leads to a perceptual benefit by shortening the onset of perceptual processes.

SY_31.4 - The ups and downs of temporal orienting: Different effects of temporal expectations on early auditory processing

Lange, K.

Heinrich Heine Universität Düsseldorf, Düsseldorf, Germany

Temporal expectations can induce an orienting of attention to the expected point in time. On a behavioral level, it has been consistently shown that this temporal orienting leads to faster responding to attended compared to unattended stimuli. Regardless of how exactly temporal expectations were induced, these behavioral effects have been accompanied by an enhancement of the P300 wave of the auditory event-related potential. This suggests that temporal orienting affects processes localized relatively late in the auditory processing stream. By contrast, effects of temporal orienting on early auditory processing (as measured by the auditory N1) are more diverse. Early effects depend on the underlying temporal expectations and on whether or not the timing of the stimuli can be anticipated reliably. In the talk, I will present data of three experiments in which temporal expectations were based on different experimental manipulations, leading to distinct effects of temporal orienting on the auditory N1. When temporal expectations were based solely on statistical properties of the stimulation, no effects of temporal orienting on the auditory N1 were observed. When temporal expectations were rhythmical, based on a regular (vs. an irregular) stimulus sequence prior to the critical tone, the effect of temporal orienting on the N1 depended on whether the sequence reliably predicted the tone’s onset or not. Reliable predictions of the tone’s onset were associated with a reduced N1. By contrast, rhythmic expectations lead to an enhancement of the auditory N1 when participants could not be certain about the timing of the tone. Thus, the present data suggest that effects of temporal orienting on early sensory processing steps depend crucially on the involved temporal expectations, whereas temporal orienting effects in later, response-related processing stages are independent of how exactly the underlying temporal expectations are achieved.

SY_31.5 - The power of rhythms in modulating early auditory processing

Correa, A. & Sanabria, D.

Universidad de Granada, Spain

In this talk I will present electrophysiological evidence showing that rhythms can induce strong temporal expectations and modulations of early auditory processing exogenously, that is, even when the rhythm does not predict the time of target onset.

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