Inhibition impairments in Alzheimer's disease, mild cognitive impairment and healthy aging: effect of congruency proportion in a Stroop task.
The goal of this study was to assess inhibition and goal maintenance in persons with Alzheimer's disease, mild cognitive impairment, healthy older adults and younger adults. This was done by using a task that compared the Stroop effect in pure blocks, that comprised only incongruent trials, with the Stroop effect in mixed blocks, in which 25% of trials were incongruent and 75% were congruent (Kane & Engle, 2003). Those conditions were administered to 20 healthy younger and 20 older control participants, and to 20 participants meeting criteria for MCI and 11 for AD. Results show reduced resistance to interference as a consequence of healthy aging and only partially impaired goal-maintenance capacities. Interference and goal maintenance are also impaired when comparing MCI and AD to healthy older adults, with AD suffering from a more severe impairment than MCI. In addition, there is a partial preservation of goal-maintenance capacities in MCI because reducing response speed allows them to maintain a level of error rate similar to that of healthy older adults. In contrast, AD persons suffer from a complete breakdown of goal-maintenance capacities, as is suggested by deficits on both response time and error rates.
Bélanger
Sara
S
Centre de recherche, Institut universitaire de gériatrie de Montréal, Centre de recherche en neuropsychologie et cognition, Department of Psychology, University of Montreal, Canada.
Belleville
Sylvie
S
Gauthier
Serge
S
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000544:Alzheimer Disease / Q000503:physiopathology / Q000523:psychology*; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000503:physiopathology / Q000523:psychology*; D056344:Executive Function / Q000502:physiology*; D015577:Geriatric Assessment; D006801:Humans; D007266:Inhibition, Psychological; D009042:Motivation; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013223:Statistics as Topic; D057190:Stroop Test; D055815:Young Adult