Tactile temporal offset cues reduce visual representational momentum

The perception of dynamic objects is sometimes biased. For example, localizing a moving object after it has disappeared results in a perceptual shift in the direction of motion, a bias known as representational momentum. We investigated whether the temporal characteristics of an irrelevant, spatially uninformative vibrotactile stimulus bias the perceived location of a visual target. In two visuotactile experiments, participants judged the final location of a dynamic, visual target. Simultaneously, a continuous (starting with the onset of the visual target, Experiments 1 and 2) or brief (33-ms stimulation, Experiment 2) vibrotactile stimulus (at the palm of participant’s hands) was presented, and the offset disparity between the visual target and tactile stimulation was systematically varied. The results indicate a cross-modal influence of tactile stimulation on the perceived final location of the visual target. Closer inspection of the nature of this cross-modal influence, observed here for the first time, reveals that the vibrotactile stimulus was likely just taken as a temporal cue regarding the offset of the visual target, but no strong interaction and combined processing of the two stimuli occurred. The present results are related to similar cross-modal temporal illusions and current accounts of multisensory perception, integration, and cross-modal facilitation.

Neural Repetition Suppression Modulates Time Perception: Evidence From Electrophysiology and Pupillometry

Human time perception is malleable and subject to many biases. For example, it has repeatedly been shown that stimuli that are physically intense or that are unexpected seem to last longer. Two competing hypotheses have been proposed to account for such biases: One states that these temporal illusions are the result of increased levels of arousal that speeds up neural clock dynamics, whereas the alternative “magnitude coding” account states that the magnitude of sensory responses causally modulates perceived durations. Common experimental paradigms used to study temporal biases cannot dissociate between these accounts, as arousal and sensory magnitude covary and modulate each other. Here, we present two temporal discrimination experiments where two flashing stimuli demarcated the start and end of a to-be-timed interval. These stimuli could be either in the same or a different location, which led to different sensory responses because of neural repetition suppression. Crucially, changes and repetitions were fully predictable, which allowed us to explore effects of sensory response magnitude without changes in arousal or surprise. Intervals with changing markers were perceived as lasting longer than those with repeating markers. We measured EEG (Experiment 1) and pupil size (Experiment 2) and found that temporal perception was related to changes in ERPs (P2) and pupil constriction, both of which have been related to responses in the sensory cortex. Conversely, correlates of surprise and arousal (P3 amplitude and pupil dilation) were unaffected by stimulus repetitions and changes. These results demonstrate, for the first time, that sensory magnitude affects time perception even under constant levels of arousal.

Change biases identify the features that drive time perception

[This paper has not been peer reviewed. Please do not copy or cite without author's permission.] Time perception is malleable, and the perceived duration of stimuli can be strongly affected by the sensory response they evoke. Such ‘temporal illusions’ provide a window on how different sensory systems contribute to our sense of time. Evidence suggests that the sensory response to different features affects time perception to different extents, mediated by the level of arousal or surprise that they evoke. This, however, makes it difficult to disentangle effects of the sensory response itself from the derived arousal or surprise effects. Here, we demonstrate that time perception is differentially affected by different stimulus features when arousal and surprise are kept constant. In four temporal discrimination experiments, participants judged the duration of an interval marked by two briefly presented visual markers. Markers either repeated or changed along one of six feature dimensions, in a manner fully predictable to participants. Repetitions and changes would modulate sensory response magnitudes due to neural repetition suppression. Results showed that intervals were perceived as longer when markers changed in location, size or numerosity. Conversely, changes in face identity, orientation or luminance did not affect time perception. These results point to neural and functional selectivity in the way different stimulus features affect time perception.

Knowing your Heart Reduces Emotion-Induced Time Dilation

Human timing and interoception are closely coupled. Thus, temporal illusions like, for example, emotion-induced time dilation, are profoundly affected by interoceptive processes. Emotion-induced time dilation refers to the effect when emotion, especially in the arousal dimension, leads to the systematic overestimation of intervals. The close relation to interoception became evident in previous studies which showed increased time dilation when participants focused on interoceptive signals. In the present study we show that individuals with particularly high interoceptive accuracy are able to shield their timing functions to some degree from interference by arousal. Participants performed a temporal bisection task with low-arousal and high-arousal stimuli, and subsequently reported their interoceptive accuracy via a questionnaire. A substantial arousal-induced time dilation effect was observed, which was negatively correlated with participants’ interoceptive accuracy. Our findings support a pivotal role of interoception in temporal illusions, and are discussed in relation to neuropsychological accounts of interoception.

Stimulus-Induced Temporal Illusions: When Awareness Is Mesmerized by Time

Our subjective experience of time intervals is susceptible to the effects of the various properties of the timed stimuli/events (e.g., motion, size, affect). For instance, subjective time is considerably lengthened when observing faster and shortened when observing slower walking animations. Such effects on perceived time have been investigated widely in the field. What we do not know based on these studies is if participants are aware of these sorts of stimulus-induced timing illusions. Thus, the current study, using confidence ratings, investigated whether the participants are aware of their largely biased time perception induced by the observed walking speed in a temporal bisection task. After each categorization of a probe interval as ‘short’ or ‘long’, we asked participants to rate their confidence level regarding their categorization. We reasoned that if participants were aware of their biased time perception, the temporal modulation of confidence ratings regarding their categorization performance would not change between different walking speed conditions. We found that confidence ratings closely tracked shifts in the psychometric functions suggesting that participants were not aware of the stimulus-induced warping of perceived time. We replicated these findings in a second experiment. Our results show that human participants are not aware of the stimulus-induced temporal illusions they experience.

Causal Beliefs and Perception of Temporal Order: The ‘Reordering Effect’

Empirical research on the relationship between temporality and causation is mostly dominated by the question of how temporal information constrains causal cognition. However, Bechlivanidis and Lagnado (2013, Psychol. Sci., 24, 1563–1572; 2016, Cognition, 146, 58–66) recently claimed to have discovered the ‘reordering effect’, in which causal beliefs have an influence on perception of temporal order. This paper argues for an attentional interpretation of this effect and suggests a solution to the circularity that arises from the mutual constraint between causal assumptions and perception of temporal order. Finally, it is shown how the reordering effect may challenge certain philosophical accounts of temporal illusions.