A Matched Comparison Across Three Different Sensory Pairs of Cross-Modal Temporal Recalibration From Sustained and Transient Adaptation (original) (raw)

Rapid temporal recalibration is unique to audiovisual stimuli

Experimental brain research, 2015

Following prolonged exposure to asynchronous multisensory signals, the brain adapts to reduce the perceived asynchrony. Here, in three separate experiments, participants performed a synchrony judgment task on audiovisual, audiotactile or visuotactile stimuli and we used inter-trial analyses to examine whether temporal recalibration occurs rapidly on the basis of a single asynchronous trial. Even though all combinations used the same subjects, task and design, temporal recalibration occurred for audiovisual stimuli (i.e., the point of subjective simultaneity depended on the preceding trial's modality order), but none occurred when the same auditory or visual event was combined with a tactile event. Contrary to findings from prolonged adaptation studies showing recalibration for all three combinations, we show that rapid, inter-trial recalibration is unique to audiovisual stimuli. We conclude that recalibration occurs at two different timescales for audiovisual stimuli (fast and s...

Audiovisual temporal recalibration occurs independently at two different time scales

Combining signals across the senses improves precision and speed of perception, although this multisensory benefit declines for asynchronous signals. Multisensory events may produce synchronized stimuli at source but asynchronies inevitably arise due to distance, intensity, attention and neural latencies. Temporal recalibration is an adaptive phenomenon that serves to perceptually realign physically asynchronous signals. Recently, it was discovered that temporal recalibration occurs far more rapidly than previously thought and does not require minutes of adaptation. Using a classical audiovisual simultaneity task and a series of brief flashes and tones varying in onset asynchrony, perceived simultaneity on a given trial was found to shift in the direction of the preceding trial’s asynchrony. Here we examine whether this inter-trial recalibration reflects the same process as prolonged adaptation by combining both paradigms: participants adapted to a fixed temporal lag for several minutes followed by a rapid series of test trials requiring a synchrony judgment. Interestingly, we find evidence of recalibration from prolonged adaptation and inter-trial recalibration within a single experiment. We show a dissociation in which sustained adaptation produces a large but decaying recalibration effect whilst inter-trial recalibration produces large transient effects whose sign matches that of the previous trial.

Temporal recalibration to tactile–visual asynchronous stimuli

Neuroscience Letters, 2008

Here we demonstrate that the perceptual system adapts to tactile-visual temporal asynchronies (i.e., temporal recalibration). Participants were exposed to a train of tactile and visual stimuli with a constant time lag (either −100 ms, 0 ms, or 100 ms; with negative values indicating that the tactile stimulus came first). Following exposure, they were presented tactile-visual test stimulus pairs and judged whether the tactile or the visual stimulus was presented first (Temporal Order Judgement). Results show that subjective simultaneity (the PSS) was shifted in the direction of the exposure lag. The results fit reports on auditory-visual temporal recalibration and indicate that the brain adapts to temporal incongruencies between modalities in general.

Audio-motor but not visuo-motor temporal recalibration speeds up sensory processing

PLOS ONE, 2017

Perception of synchrony between one's own action (a finger tap) and the sensory feedback thereof (a visual flash or an auditory pip) can be recalibrated after exposure to an artificially inserted delay between them (temporal recalibration effect: TRE). TRE might be mediated by a compensatory shift of motor timing (when did I tap?) and/or the sensory timing of the feedback (when did I hear/see the feedback?). To examine this, we asked participants to voluntarily tap their index finger at a constant pace while receiving visual or auditory feedback (a flash or pip) that was either synced or somewhat delayed relative to the tap. Following this exposure phase, they then performed a simple reaction time (RT) task to measure the sensory timing of the exposure stimulus, and a sensorimotor synchronization (SMS) task (tapping in synchrony with a flash or pip as pacing stimulus) to measure the point of subjective synchrony between the tap and pacing stimulus. The results showed that after exposure to delayed auditory feedback, participants tapped earlier (~21.5 ms) relative to auditory pacing stimuli (= temporal recalibration) and reacted faster (~5.6 ms) to auditory stimuli. For visual exposure and test stimuli, there were no such compensatory effects. These results indicate that adjustments of audio-motor synchrony can to some extent be explained by a change in the speed of auditory sensory processing. We discuss this in terms of an attentional modulation of sensory processing.

The Build-Up and Transfer of Sensorimotor Temporal Recalibration Measured via a Synchronization Task

Frontiers in Psychology, 2012

The timing relation between a motor action and the sensory consequences of that action can be adapted by exposing participants to artificially delayed feedback (temporal recalibration). Here, we demonstrate that a sensorimotor synchronization task (i.e., tapping the index finger in synchrony with a pacing signal) can be used as a measure of temporal recalibration. Participants were first exposed to a constant delay (∼150 ms) between a voluntary action (a finger tap) and an external feedback stimulus of that action (a visual flash or auditory tone). A subjective "no-delay" condition (∼50 ms) served as baseline. After a short exposure phase to delayed feedback participants performed the tapping task in which they tapped their finger in synchrony with a flash or tone.Temporal recalibration manifested itself in that taps were given ∼20 ms earlier after exposure to 150 ms delays than in the case of 50 ms delays. This effect quickly built up (within 60 taps) and was bigger for auditory than visual adapters. In Experiment 2, we tested whether temporal recalibration would transfer across modalities by switching the modality of the adapter and pacing signal. Temporal recalibration transferred from visual adapter to auditory test, but not from auditory adapter to visual test. This asymmetric transfer suggests that sensory-specific effects are at play.

Adaptation to audiovisual asynchrony modulates the speeded detection of sound

Proceedings of The National Academy of Sciences, 2009

The brain adapts to asynchronous audiovisual signals by reducing the subjective temporal lag between them. However, it is currently unclear which sensory signal (visual or auditory) shifts toward the other. According to the idea that the auditory system codes temporal information more precisely than the visual system, one should expect to find some temporal shift of vision toward audition (as in the temporal ventriloquism effect) as a result of adaptation to asynchronous audiovisual signals. Given that visual information gives a more exact estimate of the time of occurrence of distal events than auditory information (due to the fact that the time of arrival of visual information regarding an external event is always closer to the time at which this event occurred), the opposite result could also be expected. Here, we demonstrate that participants' speeded reaction times (RTs) to auditory (but, critically, not visual) stimuli are altered following adaptation to asynchronous audiovisual stimuli. After receiving ''baseline'' exposure to synchrony, participants were exposed either to auditory-lagging asynchrony (VA group) or to auditory-leading asynchrony (AV group). The results revealed that RTs to sounds became progressively faster (in the VA group) or slower (in the AV group) as participants' exposure to asynchrony increased, thus providing empirical evidence that speeded responses to sounds are influenced by exposure to audiovisual asynchrony. audition ͉ perception ͉ vision ͉ time ͉ recalibration www.pnas.org͞cgi͞doi͞10.1073͞pnas.0810486106 PNAS ͉ June 9, 2009 ͉ vol. 106 ͉ no. 23 ͉ 9169 -9173 NEUROSCIENCE PSYCHOLOGY

Adaptation to audiotactile asynchrony

Neuroscience Letters, 2007

Previous research has revealed the existence of perceptual mechanisms that compensate for slight temporal asynchronies between auditory and visual signals. We investigated whether temporal recalibration would also occur between auditory and tactile stimuli. Participants were exposed to streams of brief auditory and tactile stimuli presented in synchrony, or else with the auditory stimulus leading by 75 ms. After the exposure phase, the participants made temporal order judgments regarding pairs of auditory and tactile events occurring at varying stimulus onset asynchronies. The results showed that the minimal interval necessary to correctly resolve audiotactile temporal order was larger after exposure to the desynchronized streams than after exposure to the synchronous streams. This suggests the existence of a mechanism to compensate for audiotactile asynchronies that results in a widening of the temporal window for multisensory integration.

No effect of auditory–visual spatial disparity on temporal recalibration

Experimental Brain Research, 2007

It is known that the brain adaptively recalibrates itself to small (»100 ms) auditory-visual (AV) temporal asynchronies so as to maintain intersensory temporal coherence. Here we explored whether spatial disparity between a sound and light aVects AV temporal recalibration. Participants were exposed to a train of asynchronous AV stimulus pairs (sound-Wrst or light-Wrst) with sounds and lights emanating from either the same or a diVerent location. Following a short exposure phase, participants were tested on an AV temporal order judgement (TOJ) task. Temporal recalibration manifested itself as a shift of subjective simultaneity in the direction of the adapted audiovisual lag. The shift was equally big when exposure and test stimuli were presented from the same or diVerent locations. These results provide strong evidence for the idea that spatial co-localisation is not a necessary constraint for intersensory pairing to occur.

Rapid Recalibration to Audiovisual Asynchrony

Journal of Neuroscience, 2013

To combine information from different sensory modalities, the brain must deal with considerable temporal uncertainty. In natural environments, an external event may produce simultaneous auditory and visual signals yet they will invariably activate the brain asynchronously due to different propagation speeds for light and sound, and different neural response latencies once the signals reach the receptors. One strategy the brain uses to deal with audiovisual timing variation is to adapt to a prevailing asynchrony to help realign the signals. Here, using psychophysical methods in human subjects, we investigate audiovisual recalibration and show that it takes place extremely rapidly without explicit periods of adaptation. Our results demonstrate that exposure to a single, brief asynchrony is sufficient to produce strong recalibration effects. Recalibration occurs regardless of whether the preceding trial was perceived as synchronous, and regardless of whether a response was required. We propose that this rapid recalibration is a fast-acting sensory effect, rather than a higher-level cognitive process. An account in terms of response bias is unlikely due to a strong asymmetry whereby stimuli with vision leading produce bigger recalibrations than audition leading. A fast-acting recalibration mechanism provides a means for overcoming inevitable audiovisual timing variation and serves to rapidly realign signals at onset to maximize the perceptual benefits of audiovisual integration.