SuperAgers with a Super Memory

In a recent experiment1 SuperAgers were defined as individuals over 80 with episodic memory performance at least as good as normative values for 50- to 65-year olds. The performance of these SuperAgers was compared to two cognitively normal cohorts: age-matched elderly and 50- to 65-year olds. The brains of all three groups were compared using cortical morphometry.

With respect to memory performance, the SuperAgers performed better than both control groups (but the difference between the SuperAgers and the middle-age controls was not statistically significant, p>0.05). The sample consisted of 12 SuperAgers, 10 elderly controls, and 14 middle-age controls. The elderly control group performed significantly worse than the other two groups.

With respect to whole-brain cortical thickness elderly controls exhibited significant atrophy in the older cohort compared against the middle-aged controls in multiple regions across the frontal, parietal, and occipital lobes, including medial temporal regions important for memory. However, the whole brain cortical thickness analysis comparing the SuperAgers with the middle-aged controls did not reveal significant atrophy in the SuperAgers.

With respect to the thickness of the Anterior Cingulate Cortex, the thickness of the SuperAgers was higher than both the Elderly Controls and the Middle-Aged Controls. Somewhat surprisingly, only the difference between the SuperAgers and the Middle-Aged controls was statistically significant (p<0.05). However, the likelihood of achieving statistical significance increases as sample size increases. Research has indicated that the cingulate constitutes a critical site of transmodel integration related to episodic memory, spatial attention, cognitive control, and motivational modulation. It is unclear whether the SuperAgers were born with a particularly thick cortex or whether they resisted cortical change over time.

The relationship between brain and memory is an interesting one. The notion that more brain equates to more memory is fairly common, but this finding needs to be placed in context. Alzheimer’s cannot be diagnosed conclusively until an autopsy has been done. The key signatures for the diagnosis are amyloid plaques and neurofibrillary tangles. But these same signatures have been found in autopsies of people WHO HAD SHOWN NO SYMPTOMS OF ALZHEIMER’S WHEN THEY WERE ALIVE! So it would appear that these amyloid plaques and neurofibrillary tangles are a necessary, but not a sufficient condition for Alzheimer’s.

I remember reading an article when I was in graduate school about someone who had hydroencephalocele, which is more commonly called “water in the brain.” As a result of this condition, this individual had only about 10% of the normal volume of cortex. Yet this person led a normal life and earned a Bachelor of Science Degree in mathematics!

The plasticity of the brain is truly remarkable. Healthymemory believes that this plasticity is fostered by cognitive exercise and cognitive challenges. So, stay cognitively active and seek cognitive growth!

1Harrison, T.M., Weintraub, S., Mesulam, M.-M, & Rogalski, E. (2012). Superior Memory and Higher Cortical Volumes in Unusually Successful Aging, Journal of the International Neuropsychological Society, 18, 1-5.

© Douglas Griffith and healthymemory.wordpress.com, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

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