A common perceptual temporal limit of binding synchronous inputs across different sensory attributes and modalities

Abstract

The human brain processes different aspects of the surrounding environment through multiple sensory modalities, and each modality can be subdivided into multiple attribute-specific channels. When the brain rebinds sensory content information ('what') across different channels, temporal coincidence ('when') along with spatial coincidence ('where') provides a critical clue. It however remains unknown whether neural mechanisms for binding synchronous attributes are specific to each attribute combination, or universal and central. In human psychophysical experiments, we examined how combinations of visual, auditory and tactile attributes affect the temporal frequency limit of synchrony-based binding. The results indicated that the upper limits of cross-attribute binding were lower than those of withinattribute binding, and surprisingly similar for any combination of visual, auditory and tactile attributes (2 -3 Hz). They are unlikely to be the limits for judging synchrony, since the temporal limit of a crossattribute synchrony judgement was higher and varied with the modality combination (4 -9 Hz). These findings suggest that cross-attribute temporal binding is mediated by a slow central process that combines separately processed 'what' and 'when' properties of a single event. While the synchrony performance reflects temporal bottlenecks existing in 'when' processing, the binding performance reflects the central temporal limit of integrating 'when' and 'what' properties.

Audiotactile interactions in temporal perception

“…Fujisaki & Nishida, 2010). The link between these two kinds of perception is well described by Wackermann (2007): Temporal experience is primarily experience of succession.…”

“…Thus, the crossmodal temporal binding and the synchrony judgment task would tap into different processes in the perception of an event, thus explaining the discrepancy in the performance observed in the two tasks. However, as pointed out by the authors themselves, the reason why the temporal limit should settle around 2-3 Hz in all of the conditions is unclear, and possibly involves a precise investigation of the timing of high-level sensory processing (Fujisaki & Nishida, 2010).…”

“…However, according to Fujisaki & Nishida (2010), synchrony perception is also centrally represented, as demonstrated by the fact that the temporal limits of crossmodal synchrony perception are still much lower than the limits observed in the individual sensory modalities (cf. Fujisaki & Nishida, 2005).…”

“…The issue of a centralized versus distributed timing mechanism has been elegantly explored in a recent study by Fujisaki and Nishida (2010). The authors investigated whether the binding of synchronous attributes is specific to each attribute/sensory combination, or whether instead it occurs at a more central level.…”

“…By contrast, a low and invariant binding speed is expected when considering a shared underlying mechanism. In Fujisaki and Nishida's (2010) study, participants had to perform a binding task and a synchrony-asynchrony discrimination task. In the first task, two sequences of stimuli were presented, each of which consisting of the repetitive alternation of two attributes (e.g., in the audiotactile condition, high-or low-pitched sounds were presented together with vibrations to the right or left index finger).…”