Consider the stream of flashing lights and ringing of an ambulance siren, which share a pattern of highs and lows repeating over time. In the lab, this scenario can be reduced to simple flashes and beeps repeating at a regular rate. Our brains make sense of similar flash and beep rates by integrating them into a composite flash-beep rate, enhancing perception when rates are identical but distorting perception when they are conflicting.
For her Masters project, Cassie Brooks investigated how healthy ageing affects this process. First, she demonstrated subtle changes in the relative accuracy of perceived beep and flash rates in healthy older adults compared to younger controls. Taking these subtle age-related differences in perception into account, she then looked at how flexibly older adults were able to combine a range of conflicting flash and beep rates. The good news? The results indicate that older adults retain the ability to appropriately integrate information about the rate of repetition across vision (flashing lights) and hearing (beeping sounds).
This study has recently been published in the Journal of Vision, and is free to view here.