Abstract
Studies examining the effect of aging on audio-visual temporal order judgments (TOJs) have found mixed results. Virsu et al. (2003) and Setti et al. (2011), for example, reported that the accuracy of TOJs was reduced in older subjects, but previous research in our lab (Fiacconi et al., VSS 2011) found no effect of aging. A possible explanation for the different results concerns the role of spatial cues. Virsu et al. and Setti et al. presented auditory and visual stimuli from different locations, whereas Fiacconi et al. presented stimuli from the same perceived location. Redundant spatial cues, which improve TOJs in younger subjects (Zampini et al., 2003) were available to subjects only in the Virsu et al. and Setti et al. studies. Here we examine if age differences in sensitivity to spatial cues affects age differences in TOJs. In the current experiments, a Gabor pattern and a tone were presented on each trial with various SOAs and subjects determined which stimulus was presented first. In Experiment 1, TOJs were measured in 12 younger (22-30) and 12 older (+70) with the tone presented from speakers positioned, in separate blocks of trials, to the left or right of the visual stimulus. In Experiment 2, TOJs were measured in 17 younger (18-32) and 16 older (70+) with the tone presented from speakers and headphones in separate blocks of trials. Psychometric functions were used to estimate a just noticeable difference (JND) and point of subjective simultaneity (PSS) for each subject. In both experiments, we found no significant effect of age group, spatial cue, or group x cue interaction for either the JND or PSS. The current experiment replicates the findings of Fiacconi et al., and suggests that the difference between studies is not due to age differences in the ability to use redundant spatial cues.
Meeting abstract presented at VSS 2012