Rapid Audiovisual Temporal Recalibration Generalises Across Spatial Location.

Abstract

Recent exposure to asynchronous multisensory signals has been shown to shift perceived timing between the sensory modalities, a phenomenon known as 'temporal recalibration'. Recently, Van der Burg et al. (2013, J Neurosci, 33, pp. 14633-14637) reported results showing that recalibration to asynchronous audiovisual events can happen extremely rapidly. In an extended series of variously asynchronous trials, simultaneity judgements were analysed based on the modality order in the preceding trial and showed that shifts in the point of subjective synchrony occurred almost instantaneously, shifting from one trial to the next. Here we replicate the finding that shifts in perceived timing occur following exposure to a single, asynchronous audiovisual stimulus and by manipulating the spatial location of the audiovisual events we demonstrate that recalibration occurs even when the adapting stimulus is presented in a different location. Timing shifts were also observed when the adapting audiovisual pair were defined only by temporal proximity, with the auditory component presented over headphones rather than being collocated with the visual stimulus. Combined with previous findings showing that timing shifts are independent of stimulus features such as colour and pitch, our finding that recalibration is not spatially specific provides strong evidence for a rapid recalibration process that is solely dependent on recent temporal information, regardless of feature or location. These rapid and automatic shifts in perceived synchrony may allow our sensory systems to flexibly adjust to the variation in timing of neural signals occurring as a result of delayed environmental transmission and differing neural latencies for processing vision and audition.