The sense of time, unlike other senses, is not generated by a specific sensory organ. Rather, all events that stimulate the brain, regardless of sensory modality, contain temporal cues. Due to heterogeneous processing of sensory events, subjective time may differ signficantly for a given durfation across modality. For example, an auditory event is often perceived longer than a visual event of the same phyiscal inerval. Subjective time is also susceptible to temporal context, voluntary actions, attention, arousal and emotional states. In this research topic, we focus on mechanisms underlying temporal process and multisensory integration in time perception using behavioral investigation and Bayesian modeling.
Bayesian Optimization of time perception
Subjective time frequently departs from physical time, causing various types of temporal contextual effects, such as the central tendency effect. In reently review papers (Shi, Church, & Meck, 2013; Shi & Burr, 2016) we suggest that subjective time arises from minimizing prediction errors and adaptive recalibration, which can be unified in Bayesian framework with information-processing models of timing, a framework rooted in Helmholtz's 'perception as inference'.
Optimal integration in auditory duration reproduction
Duration estimation is known to be far from veridical and to differ for sensory estiamtes and motor reproductions. Our brain encounters challenges to integrate different sources of temporal information so as to enable accurate timing for multisensory or sensorimotor events. To investigate sensorimotor integration of duration, Shi, Ganzenmüller and Müller (2013) compared three different duration estimation tasks: perceptual comparison, motor reproduction, and auditory reproduction. The auditory reproduction task is a combined perceptual-motor task. They found consistent overestimation in both motor and perceptual-motor auditory reproduction tasks. Using Bayesian approach, Shi et al. (2013) found the prediction from the MLE model is in good agreement with the behavioral results.
Influence of visual emotional pictures on tactile duration judgment
Judging the duration of emotional stimuli is known to be influenced by their valence and arousal values. However, whether and how perceiving emotion in one modality affects time perception in another modality is still unclear. In this study (Shi, et al., 2012), we compared the influence of different types of emotional pictures—a picture of threat, disgust, or a neutral picture presented at the start of a trial—on temporal bisection judgments of the duration of a subsequently presented vibrotactile stimulus. We found systematically modulation of visual threat on the perceived tactile duration, suggesting that crossmodal linkages in the processing of emotions and emotional regulation are two main factors underlying the manifestation of crossmodal duration modulation.
Duration reproduction with sensory feedback delay
Research showes that voluntary action can attract subsequent events towards the action. However, whether and how sensorimotor delay affects duration reproduction is still unclear. Is the onset timing of feedback important for duration reproduction? How does feedback duration influence your motor reproduction? By injecting onset- and offset-delays in a reproduced signal, Ganzenmüller and colleagues (Ganzenmüller, Shi, & Müller, 2012) found that the reproduced duration was lengthened in both visual and auditory onset-manipulation conditions. The lengthening effect was evident immediately. In contrast, a shortening effect was found with feedback signal offset-delay, though the effect was weaker and manifested only in the auditory offset-delay condition. These findings indicate that participants tend to mix the onset of action and the feedback signal more when the feedback is delayed, and they heavily rely on motor-stop signals for the duration reproduction.
- Shi, Z. *, Burr, D. (2015), Predictive coding of multisensory timing, Current Opinion in Behavioral Sciences. (in press)
- Shi, Z., Church, R. M., Meck, W. H. (2013), Bayesian optimization of time perception, Trends in Cognitive Sciences, 17(11), 556-564. DOI:10.1016/j.tics.2013.09.009
- Shi, Z., Ganzenmüller, S., & Müller, H. J. (2013). Reducing Bias in Auditory Duration Reproduction by Integrating the Reproduced Signal. (W. H. Meck, Ed.)PLoS ONE, 8(4), e62065. doi:10.1371/journal.pone.0062065
- Shi, Z., Jia, L., Müller, H. J. (2012), Modulation of tactile duration judgments by emotional pictures, Front. Integr. Neurosci. 6:24. doi: 10.3389/fnint.2012.00024
- Ganzenmüller, S., Shi, Z., & Müller, H. J. (2012). Duration reproduction with sensory feedback delay: differential involvement of perception and action time. Frontiers in Integrative Neuroscience, 6(October), 1–11. doi:10.3389/fnint.2012.00095