Abstract
From speech recognition to music performance, perceiving synchrony and temporal order between auditory and visual inputs is crucially important for our daily life. However, due to the temporal variabilities of signal transmission in the environment as well as sensory processing, the perceptual system has to compensate for such noisy sensory inputs to achieve stable representations of integrated multisensory events. To solve this problem, the timing system exploits the temporal redundancy of events and biases the perception of current audiovisual lag towards or against previously perceived lags, depending on task or sensory modality (Roseboom, 2019; Van der Burg et al., 2013). The attractive serial effect is consistent with a phenomenon called serial dependence that has been widely reported in visual perception (Cicchini et al., 2014; Fischer & Whitney, 2014; Liberman, et al., 2014). In the present study, we tested the spatial and feature tuning of the serial dependence in timing perception. In the experiment, auditory and visual stimuli were briefly presented with various stimulus onset asynchronies (SOAs), and participants judged which stimulus appeared first. The visual stimulus was presented at a random location along an invisible concentric ring with a radius of 7 degrees. We replicated serial dependence in timing perception: the perceived lag between auditory and visual stimuli was biased toward previously presented audiovisual lags. Furthermore, this serial dependency occurred only when the location of the visual stimulus in the current trial was near the previous stimulus location. In addition to spatial tuning, the serial effect was stronger when the current and previous audiovisual lags were close to each other, indicating the feature tuning of this effect. Our results suggest that the serial dependence in timing perception cannot be explained by generic decision inertia or response biases, but is tuned to sensory properties such as visual location and audiovisual lag.