Abstract
Temporal synchrony provides a critical cue to bind multiple sensory signals processed in parallel. The speed of temporal binding of sensory signals, processed in parallel, can be psychophysically estimated from the critical temporal frequency beyond which observers cannot discriminate the temporal relationship between two oscillating stimulus sequences (i.e., whether A is in synchrony with X or Y for a sequence pair of ABABAB… and XYXYXY…). In vision, it has been reported that the upper temporal limits for within-attribute binding are relatively high (8-20 Hz), while those for cross-attribute binding are relatively low (~2.5 Hz) (Fujisaki & Nishida, 2010, Proc Biol Sci.). Here we examined whether similar results can be observed in audition. In the auditory within-attribute condition, an alternation of 1108.8 Hz and 523.2 Hz pure tones was paired with an alternation of 493.9 Hz and 293.7 Hz pure tones. Participants judged whether the 1108.8 Hz was in phase with 493.9 Hz or 293.7 Hz. In the auditory cross-attribute condition, an alternation of high-pitched and low-pitched pure tones (367.0 Hz and 261.6 Hz) and an alternation of two different band-pass noise bursts (3000-3500 Hz and 2000-2500 Hz) were compared. Auditory sequences were presented to participants dichotically via headphones. In the visual cross-attribute condition, two color alternation (red, green) and two orientation alternation (45°clockwise, anticlockwise tilts from the vertical of gratings) were compared. Results showed that the temporal frequency limit for auditory within-attribute binding was around 12 Hz, while it was around 3.5 Hz for auditory cross-attribute binding. The temporal frequency limit for visual cross-attribute binding was around 2.5 Hz, consistent with the previous reports. These findings suggest that the feature-specific mechanism for within-attribute temporal binding is fast, while the feature-invariant mechanism for cross-attribute binding is slow, both in vision and audition.
Meeting abstract presented at VSS 2012