Oxyhemoglobin changes in the prefrontal cortex in response to cognitive tasks: a systematic review

• Published in: International journal of neuroscience 2019-02, Vol.129 (2), p.194-202
• Main Authors: Bonetti, Leandro Viçosa, Hassan, Syed A., Lau, Sin-Tung, Melo, Luana T., Tanaka, Takako, Patterson, Kara K., Reid, W. Darlene
• Format: Article
• Language: English
• Subjects: cognitive task; healthy subjects; near infrared spectroscopy; oxyhemoglobins; Prefrontal cortex
• ISSN: 0020-7454; 1543-5245; 1563-5279
• DOI: 10.1080/00207454.2018.1518906

Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design. Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility. Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO 2 Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as "Working Memory" and "Verbal Fluency Tasks". Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.