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,
newcl.org/eidels, 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.
For more details or feedback please feel free to contact me
directly at Ami.Eidels@newcastle.edu.au
