Journals of Gerontology Series B: Psychological Sciences and Social Sciences, Vol 53, Issue 3 P189-P200, Copyright © 1998 by The Gerontological Society of America
Visual search tasks: slowing of strategic and nonstrategic processes in the nonlexical domain
MF Gorman and DL Fisher
Department of Mechanical and Industrial Engineering, University of Massachusetts at Amherst 01003, USA.
Some investigators have argued that aging affects the slowing of processes
in nonlexical tasks more than it does the slowing of processes in lexical
tasks, but that within task domains, the slowing is identical. Other
investigators have argued that even within nonlexical tasks there is
differential slowing such that aging affects processing speed more in
(nonlexical) coordinative tasks than it does in (nonlexical) sequential
tasks. Perhaps, more finely still, there is a differential slowing in
coordinative nonlexical tasks. Toward this end, latent models of general
and process-specific slowing in coordinative nonlexical tasks were
formulated for older adults. A visual search task was then used to test the
two types of models. It was found that a latent model of process-specific
slowing explained significantly more of the variability than a latent model
of general slowing, indicating that there is a differential slowing of
processes among coordinative tasks within the nonlexical domain. It was
also discovered that the coordinative process most greatly affected was
that of deciding to terminate the search when no target was present in the
display, indicating together with other studies a possible difference in
the slowing of strategic processes among both coordinative and sequential
tasks within the nonlexical domain, but no difference in the slowing of
nonstrategic processes.
