Abstract
Previous research has demonstrated age-related changes in vision and audition. Given these changes, age-related differences in multimodal integration might be expected, but there is relatively little research examining how multimodal integration changes with advancing age. The current study used the sound-induced flash illusion (Shams, Kamitani & Shimojo, 2002), the perception of multiple flashes of a single presented flash when paired with multiple beeps, to examine multimodal integration in younger (mean age 21.4, range 20-23) and older (mean age 71.6, range 66-77) individuals. Twelve younger and twelve older individuals participated in the study. On each trial participants were presented 1-3 flashes of a white disc (127.97 cd/m2), 12° visual angle below fixation presented on a black background (0.06 cd/m2). These flashes were paired with 0-3 beeps (3.5 kHz sine wave tones). Prior to participation in the experiment, their ability to discriminate 1-3 visual flashes and 1-3 auditory beeps was assessed and required to progress further in the study. Participants were asked to report the number of flashes perceived on each trial and to ignore the beeps. In addition, to assess the effects of attentional load, a go/no-go paradigm was used with one block run with a no-go signal on 12% of the trials in the visual domain and one block run with a no-go signal on 12% of the trials in the auditory domain. Results indicate that multimodal integration is retained by older individuals. However, older as compared to younger individuals showed a greater effect of the number of beeps when the difference between the number of beeps and flashes was more disparate. Attentional load did influence the strength of the illusion but did not differ with age. The importance of these findings to aging, attentional load, selectivity and the mechanisms of multimodal integration will be discussed.
Meeting abstract presented at VSS 2012