The effect of balance training on audio–visual integration in older adults

Although the vestibular system is involved in maintaining balance and posture control, recent studies have provided evidence for a crucial role of other sensory modalities in this task. In older adults, reduced visual capacity, specifically impaired depth perception and contrast sensitivity, has been associated with an increased risk of falls. Moreover, using the auditory-flash illusion (Shams et al., 2000) we recently reported that auditory–visual perception is less efficient in fall-prone older adults than in their age-matched counterparts (Setti et al., 2011) and that susceptibility increases with ageing. The aim of this study was to investigate whether balance training is associated with changes in how efficiently auditory and visual information is integrated in older adults. We tested 58 older (65+ years) adults, half of whom took part in a balance training intervention programme over a series of 5 weeks and half of whom were controls. Pre- and post-training measures of balance control (e.g., Berg Balance Scale) and movement-based signals (e.g., displacement of centre of pressure) across groups suggested that the intervention was successful in improving overall balance control. Furthermore, we found that susceptibility to the auditory-flash illusion did not increase for the intervention group, but did increase in the control group over time. Furthermore, following balance training our data suggest that audio–visual integration becomes relatively more efficient in fall-prone than in non-fall prone older adults. Our findings suggest important links between balance control and multisensory interactions in the ageing brain.