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Difference between Okinawan and Dutch elderly in working memory‐related brain activation
Author(s) -
ĆurčićBlake Branislava,
Willcox Craig D,
Futenma Yuko,
Ueda Yukihiko,
Aleman André
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.042608
Subject(s) - verbal fluency test , fluency , task (project management) , working memory , dementia , executive functions , cognition , psychology , audiology , cognitive psychology , medicine , neuropsychology , psychiatry , mathematics education , management , disease , economics , pathology
Background Okinawan elderly have been reported to suffer from less age‐related diseases (including dementia) in comparison to elderly people elsewhere. However, there is a lack of research studying functional brain characteristics of succesful aging as found in Okinawan elderly. The current study is designed to take the first step in this regard. Specifically, we want to investigate brain activation during executive functioning in Okinawan elderly as compared to Western‐European elderly (in this case, Dutch elderly). We predicted that Okinawan elderly would need less prefrontal brain activation during a working memory task. Method We included the first data from 50 participants of the Okinawa‐Groningen study in which brain activation patterns are studied cross‐culturally in eldery subjects. The study is ongoing and aims to include N=40 at both sites. Here we present the first results based on a comparison of 34 Okinawan to 16 Dutch participants. Working memory‐related brain activation was measured using fNIRS during a visual N‐back task. 1‐back task consisted of 3 blocks (120s) including figures of objects and animals. fNIRS measurement was performed with 16 optodes (NIRx Scout, Germany) placed between Fp1 and F5 on the left and Fp2 and F6 on the right side. fNIRS data were analyzed using NIRSLab (NIRx, Germany). As groups differed slightly in level of education (higher in the Dutch sample) we included cognitive performance on a related task, verbal fluency (category and letter fluency) as covariate, to control for cognitive ability. Result GLM analysis revealed significantly higher activation in the bilateral Inferior Frontal Gyrus (IFG) of Dutch participants. After correcting for performance on verbal fluency ANCOVA revealed significantly stronger IFG activation in the Dutch subjects, F(3, 47)=9.83 (0.003). Though in the same direction, this difference was non‐significant for the left IFG (p=0.062). Conclusion Our results reveal lower of activation of dorsolateral prefrontal cortex during working memory processing in elderly subjects from Okinawa as compared to elderly Dutch subjects. Cognitive reserve has been shown to be related to less activation during a task involving executive functioning (Oh et al. 2018). We suggest that Okinawan elderly may need less executive processing resources to perform the task.