Abstract
With ageing sensory acuity declines, however, recent studies suggest that perception is compensated by combining inputs from across the various senses [Laurienti, et al., 2006]. However, perception can be compromised when unrelated sensory information is combined across the senses [Poliakoff et al., 2006]. What is not known is how efficient is multisensory integration in older adults when the task is to search for an object in a large spatial array. In a task involving visual target localisation, we investigated whether an auditory stimulus presented from the same location improves performance relative to a visual-only condition and whether an auditory target presented to a different location (left or right, in front or behind) to the visual target compromises performance. We also tested whether these effects were more pronounced in older than younger adults. In Experiment 1, we manipulated the spatial congruency between the auditory and visual events along the depth plane (z-axis) and in Experiment 2 along the horizontal plane (x-axis). Overall, performance was worse for older than younger adults in both experiments. In particular, performance in the older adults group did not benefit from spatial congruency between the visual target and the auditory non target, but it was hindered by a sound coming from a spatially incongruent depth location. Conversely, in Exp.2 no detrimental effect of a spatially incongruent sound on the horizontal plane was found in the older adult group suggesting that visuo-spatial processing is not affected by sounds mislocated to the left or right. These results show that when auditory and visual stimuli are available older adults may integrate unreliable auditory inputs to perform a visual task, in particular along the depth plane. These findings support the idea that multisensory integration is enhanced in older relative to younger adults.
This research was completed as part of a wider programme of research within the TRIL Centre, (Technology Research for Independent Living). The TRIL Centre is a multi-disciplinary research centre, bringing together researchers from UCD, TCD, NUIG and Intel, funded by Intel and IDA Ireland. www.trilcentre.org.