Audiovisual Simultaneity Judgment and Rapid Recalibration throughout the Lifespan

Abstract

Multisensory interactions are well established to convey an array of perceptual and behavioral benefits. One of the key features of multisensory interactions is the temporal structure of the stimuli combined. In an effort to better characterize how temporal factors influence multisensory interactions across the lifespan, we examined audiovisual simultaneity judgment and the degree of rapid recalibration to paired audiovisual stimuli (Flash-Beep and Speech) in a sample of 220 participants ranging from 7 to 86 years of age. Results demonstrate a surprisingly protracted developmental time-course for both audiovisual simultaneity judgment and rapid recalibration, with neither reaching maturity until well into adolescence. Interestingly, correlational analyses revealed that audiovisual simultaneity judgments (i.e., the size of the audiovisual temporal window of simultaneity) and rapid recalibration significantly co-varied as a function of age. Together, our results represent the most complete description of age-related changes in audiovisual simultaneity judgments to date, as well as being the first to describe changes in the degree of rapid recalibration as a function of age. We propose that the developmental time-course of rapid recalibration scaffolds the maturation of more durable audiovisual temporal representations.

Fig 1. Histogram of participants’ age as a function of stimulus type.

A) Distribution of the ages of participants who were presented with Flash-Beep stimuli. B) Distribution of the ages of participants who were presented with Speech stimuli.

Fig 2. Simultaneity judgment and rapid recalibration as a function of stimuli complexity and age.

Although no change is apparent in PSS (upper left), temporal window of simultaneities for both Flash-Beep (red) and Speech (black) stimuli portray protracted developmental time-courses (upper right). Similarly, rapid recalibration effects, both in terms of change in PSS (lower left) and TWS (lower right) as a function of the nature of the immediately precedent trial follow protracted developmental time-course, and a U-shape, indexing greater tendency to rely on recent perceptual experience later in life. Solid lines represent the mean of the 11-participant wide window centered at the particular age, shaded areas around the solid lines represent +/- 1 S.E.M. Dashed vertical lines represent the first age-point at which within condition values differed from the first time-point (thus, age at which the particular perceptual process reached maturity). The colored circles represent the minimum value for either the raw TWS or the change in PSS or TWS as a function of age. And finally the solid horizontal lines at the top of the panels indicate significant differences (p < 0.05) from the minimal value (circle). Hence, if these solid horizontal lines are present both at earlier and later ages than the respective minimum, we categorize the particular time-course as being U-shaped.

Fig 3. Correlation between the size of participant’s TWS and rapid recalibration (ΔPPS).

Left panel demonstrated a significant correlation between TWS and ΔPPS for Flash-Beep stimuli, while right panel demonstrates the same relation for Speech stimuli. The size of the dots indexes age of the participant represented, conveying the fact that these correlations seem to be largely driven by age.