Incremental rate of prefrontal oxygenation determines performance speed during cognitive Stroop test: the effect of ageing.
Cognitive function declines with age. The underlying mechanisms responsible for the deterioration of cognitive performance, however, remain poorly understood. We hypothesized that an incremental rate of prefrontal oxygenation during a cognitive Stroop test decreases in progress of ageing, resulting in a slowdown of cognitive performance. To test this hypothesis, we identified, using multichannel near-infrared spectroscopy, the characteristics of the oxygenated-hemoglobin concentration (Oxy-Hb) responses of the prefrontal cortex to both incongruent Stroop and congruent word-reading test. Spatial distributions of the significant changes in the three components (initial slope, peak amplitude, and area under the curve) of the Oxy-Hb response were compared between young and elderly subjects. The Stroop interference time (as a difference in total periods for executing Stroop and word-reading test, respectively) approximately doubled in elderly as compared to young subjects. The Oxy-Hb in the rostrolateral, but not caudal, prefrontal cortex increased during the Stroop test in both age groups. The initial slope of the Oxy-Hb response, rather than the peak and area under the curve, had a strong correlation with cognitive performance speed. Taken together, it is likely that the incremental rate of prefrontal oxygenation may decrease in progress of ageing, resulting in a decline in cognitive performance.
['Endo|Kana|K|', 'Liang|Nan|N|', 'Idesako|Mitsuhiro|M|', 'Ishii|Kei|K|', 'Matsukawa|Kanji|K|']
D000367:Age Factors D000368:Aged D000375:Aging D001288:Attention D003071:Cognition D056344:Executive Function D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D010108:Oxyhemoglobins D017397:Prefrontal Cortex D011930:Reaction Time D019265:Spectroscopy, Near-Infrared D057190:Stroop Test D055815:Young Adult
Prefrontal oxygenation Cognitive function Multichannel near-infrared spectroscopy Congruent word-reading test Incongruent Stroop test