Wednesday, 11 March 2015

JUST PUBLISHED! Cognitive aging and workload capacity: how do older people process information from multiple sources?

The modern world bombards us with multiple sources of information. Our ability to cope with increasing amounts of information and behave adaptively in this complex environment is sometimes referred to as ‘workload capacity’. A recent article in the open-access journal PLoS-ONE tests whether this ability changes over the life span. More specifically, the study tested how young and old adults differ in the ability to process multiple visual signals.

In laboratory studies of simple decisions older adults tend to be slower than younger participants. However, the reason for this performance detriment is not entirely clear: Are older people genuinely worse, or simply more cautious? Or, could they be more sensitive to interference from contextual factors? Dr. Ami Eidels from the School of Psychology at the University of Newcastle, along with co-authors Dr. Boaz Ben David (IDC) and Dr. Chris Donkin (UNSW), compared performance of young adults (mean age = 22 years) and older adults (mean age = 72) in a visual detection task. Participants in the study were presented with one target signal (‘X’) or multiple signals. In another condition, distractors (‘O’) could also be presented for view but the participants had to ignore the distracting items and look for target signals.

Overall, older adults were slower to detect a target by about 15%, compared with their younger counterparts. Both groups were highly accurate (more than 98% correct), so a caution explanation is not very likely. Namely, if the elderly were slower only because they were sacrificing speed for accuracy, they should have been more accurate.  Ben David, Eidels, and Donkin used cognitive modeling techniques that employ both response-times and accuracy data to separate the effects of perceptual ability, caution, and the effects of distractors. They found that the major difference between the young and old was the inability of the latter to ignore distractor information. Put bluntly, in a complex and cluttered environment older adults may not be as efficient at blocking irrelevant information. These results have important implications concerning the way we design displays and interfaces for Australia’s aging population.

The paper is available  via Ami’s website,, or directly (and for free) via PLoS-ONE: 

Ben-David B.M., Eidels A., Donkin C. (2014). Effects of Aging and Distractors on Detection of Redundant Visual Targets and Capacity: Do Older Adults Integrate Visual Targets Differently than Younger Adults? PLoS ONE, 9(12): e113551. doi:10.1371/journal.pone.0113551

Acknowledgment: the study was partially supported by the Keats Endowment Research Fund to A.E.

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