Prefrontal activity predicts individual differences in optimal attentional strategy for preventing motor performance decline: a functional near-infrared spectroscopy study

Abstract

Directing attention to movement outcomes (external focus; EF), not body movements (internal focus; IF), is a better cognitive strategy for motor performance. However, EF is not effective in some healthy individuals or stroke patients. We aimed to identify the neurological basis reflecting the individual optimal attentional strategy using functional near-infrared spectroscopy. Sixty-four participants (23 healthy young, 23 healthy elderly, and 18 acute stroke) performed a reaching movement task under IF and EF conditions. Of these, 13 healthy young participants, 11 healthy elderly participants, and 6 stroke patients showed better motor performance under EF conditions (EF-dominant), whereas the others showed IF-dominance. We then measured prefrontal activity during rhythmic hand movements under both attentional conditions. IF-dominant participants showed significantly higher left prefrontal activity than EF-dominant participants under IF condition. In addition, receiver operating characteristic analysis supported that the higher activity in the left frontopolar and dorsolateral prefrontal cortices could detect IF-dominance as an individual's optimal attentional strategy for preventing motor performance decline. Taken together, these results suggest that prefrontal activity during motor tasks reflects an individual's ability to process internal body information, thereby conferring IF-dominance. These findings could be applied for the development of individually optimized rehabilitation programs.

Distinct bilateral prefrontal activity patterns associated with the qualitative aspect of working memory characterized by individual sensory modality dominance

“…As shown in other cognitive functions such as motor imagery and focus of attention [ 9 – 11 , 21 ], we found marked variation in individual WM ability characterized by qualitative dimensions based on the dominance of sensory modality. We also found that the prefrontal activities were significantly correlated with the degree of modality dominance, supporting our hypothesis that the DLPFC and FPC is one of the important regions encoding individual qualitative aspects of the WM system.…”

“…1-5) and VD individuals (participant nos. [20][21][22][23][24]. TD individuals did not show large oxy-Hb changes over repeated fNIRS sessions.…”

“…The midpoint of an emitter/detector pair was defined as a recording channel location. The probe holder was placed on the scalp with its lowest-row center emitter at the participant's Fpz position, according to the standard international 10-20 system (the fNIRS probes and holder setups were identical with our previous study [21]).…”

“…We predicted that different FPC or DLPFC activity would be observed according to the individual's WM modality dominance evaluated in the first searching task. Specifically, our previous study exploring individual differences in attentional strategy [21] demonstrated that visual dominance was associated with less prefrontal cortex activity than tactile dominance. Therefore, if modality dominance widely influences cognitive functions, less prefrontal cortex activity should be observed in individuals that excel at holding visual information.…”

“…The left and right panels ofFig 2C illustratetypical searching cost transitions in individuals with relatively stronger TD (participant nos. 1-5) and VD (participant nos [20][21][22][23][24]…”