Cognitive Resilience and Cognitive Decline with Aging on Fluid Intelligence Tasks

Objective: Cognitive resilience refers to the phenomenon of bright people maintaining their cognitive abilities well into various forms of dementia. There is also age-related cognitive decline, as noted especially on tasks of fluid intelligence. Is age-related loss uniform regardless of intellect, or does cognitive resilience reduce the initial decline for those who are brighter, or is the decline more precipitous? To look at this we traced the performance age trajectory for those with 12 and 18 years of education on the Category Test, verbal letter fluency (FAS), Paced Auditory Serial Addition Test, and the Block Design subtest. Method: The normative data from Heaton, Miller, Taylor, and Grant (2004) were used. At each age for each of the four tests and at the two levels of education, the 50th percentile scaled score was determined, and then from this the equivalent T-score at the youngest group (20-34, 12 years of education) was determined. Results: There was no evidence for age-related cognitive resilience. As expected, those with more education performed better when younger, but there was no relative improvement in their performance as they aged. In fact, for three of the four tasks the difference between the two educational levels remained effectively the same, and for block design, the higher education group deteriorated slightly more than the other group. Conclusion(s): Although cognitive resilience protects those of higher intelligence through at least the initial stages of dementia, there is no such protection from deterioration of intellect seen with normal aging.