Age-related behavioural and neural differences in multisensory processing D McGovern1, E Roudaia1, J Stapleton1, X Li2, D Watson2, T M McGinnity2, F Newell1 |
|---|
1Institute of Neuroscience, Trinity College Dublin, Ireland |
| Ageing affects how we combine information across the senses. Recently we showed that older adults are more susceptible to the sound-induced flash illusion than younger adults. Here, we examine the timecourse and the neural correlates of the fission and fusion variants of this illusion in young and old adults. The fission illusion refers to instances where two auditory beeps cause one flash to be perceived as two. Young participants experienced fission on a smaller proportion of trials and only when the beeps were separated by short, but not longer stimulus onset asynchronies (SOAs). Older adults experienced fission more often than young participants at short SOAs, but showed no recovery with increasing SOAs. The fusion illusion refers to instances where two flashes accompanied by one beep appears as one flash. Again, young adults showed a significant illusory effect at the shortest SOA, but recovered quickly as this interval increased. Older adults were again more susceptible to this illusion overall, however, the timecourse of this effect more closely resembled that of young adults. We examine the neural correlates of both illusions with fMRI by comparing BOLD activation in early visual areas for trials where identical stimuli lead to different percepts. |
| Up Home |
|---|