Abstract
Functional near-infrared spectroscopy (fNIRS) is a non-invasive functional neuroimaging method that indirectly measures cortical activation via task-related changes in oxygenated hemoglobin (HbO). We used fNIRS during a working memory task to assess learning effect over time by assessing brain activity (fNIRS signal) and task performance. We hypothesized that in later blocks of the task, learning (better accuracy) would be correlated to less increase in HbO in prefrontal regions, indicating improved cognitive efficiency. Eighteen healthy adults [mean age = 24.9 (SD = 4.2); 14 female] engaged in 8 blocks of serial-3 subtraction for 30seconds each followed by 20seconds of rest. fNIRS data were collected in 8 cortical regions of interest (ROI) broadly covering the frontal lobe. fNIRS signal in each ROI and task-performance data were compared for the first 4 and last 4 blocks to examine learning. fNIRS signal was significantly greater for the first 4 than last 4 blocks (z = -2.1, p < 0.05) in only the right dorsolateral prefrontal cortex ROI. No learning effects appeared for any task-performance variables. These results indicate a dissociation between brain activity and task performance during a working memory task in healthy adults. There was less activity in the right dorsolateral prefrontal cortex during later than earlier trials, indicating an increase in this region's efficiency, without a change in task performance. The results suggest that fNIRS may be sensitive to change in brain activity before it appears clinically, which may be useful in studying people with conditions such as preclinical Alzheimer's disease, and in assessing subtle effects of interventions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Archives of clinical neuropsychology : the official journal of the National Academy of Neuropsychologists
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.