Unveiling Cognitive Interference: fNIRS Insights Into Poststroke Aphasia During Stroop Tasks.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Poststroke aphasia often involves cognitive deficits beyond language impairment.
• Cognitive interference and intentional inhibition are crucial for daily functioning.
• Understanding the neural underpinnings of these deficits is vital for effective rehabilitation.

Purpose of the Study:

• To investigate blood oxygenation changes during a modified Stroop task in patients with poststroke aphasia using functional near-infrared spectroscopy (fNIRS).
• To compare cognitive performance and neurophysiological responses between healthy adults and patients with poststroke aphasia.
• To identify potential neural targets for interventions aimed at improving cognitive control in poststroke aphasia.

Main Methods:

• A modified Stroop task with colored Chinese words was administered to 15 healthy adults and 15 patients with poststroke aphasia.
• Functional near-infrared spectroscopy (fNIRS) was used to measure blood oxygenation changes in brain regions.
• Behavioral data (reaction time, accuracy) and fNIRS data were analyzed across neutral, congruent, and incongruent conditions.

Main Results:

• Aphasic patients demonstrated significantly longer reaction times and reduced accuracy compared to healthy adults.
• A more pronounced interference effect was observed in the incongruent condition for aphasic patients.
• fNIRS revealed decreased activation in Broca's area, increased activation in the ventromedial frontal pole, and atypical recruitment of the left dorsolateral prefrontal cortex (DLPFC) in aphasic patients during Stroop interference.

Conclusions:

• Poststroke aphasia is associated with significant deficits in cognitive control and intentional inhibition.
• Atypical prefrontal cortex activation, particularly in the frontal pole and DLPFC, is implicated in these cognitive impairments.
• Noninvasive neuromodulation targeting these prefrontal regions may offer a promising strategy for improving cognitive control in individuals with poststroke aphasia.