TY - JOUR
T1 - Transcranial Photobiomodulation Improves Cognitive Performance in Young Healthy Adults
T2 - A Systematic Review and Meta-Analysis
AU - Salehpour, Farzad
AU - Majdi, Alireza
AU - Pazhuhi, Mahdiyeh
AU - Ghasemi, Faranak
AU - Khademi, Mahsa
AU - Pashazadeh, Fariba
AU - Hamblin, Michael R.
AU - Cassano, Paolo
N1 - Publisher Copyright:
© 2019, Mary Ann Liebert, Inc., publishers.
PY - 2019/10
Y1 - 2019/10
N2 - Background: Transcranial photobiomodulation (t-PBM) is a noninvasive modality that may improve cognitive function in both healthy and diseased subjects. Objective: This systematic review and meta-analysis addresses the question of whether t-PBM improves cognitive function in healthy adults. Methods: We searched MEDLINE using PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Library up to March 2019. We also searched ProQuest and Google Scholar databases for unpublished material. The search was limited to articles on the procognitive effects of t-PBM in healthy adults. The initial search resulted in 871 studies, of which nine publications met our criteria for inclusion and exclusion. Seven studies were performed on young, healthy subjects (17-35 years), and two studies were conducted on older (≥49 years), normal subjects. A meta-analysis was performed on six full-text publications whose subjects were young adults. Results: t-PBM administration improved cognition-related outcomes by an 0.833 standardized mean difference (SMD; 95% confidence interval (CI): 0.458-1.209, 14 comparisons) in young, healthy participants. Funnel plotting revealed asymmetry, which was validated using Egger's (p = 0.030) and Begg's regression (p = 0.006) tests. However after reanalysis, this asymmetry disappeared in the attention subgroup, but not in the memory subgroup. The trim-and-fill analysis indicated two studies were lacking required data. Thus, the effect size was adjusted from an SMD of 0.761 (95% CI: 0.573-0.949) to 0.949 (0.779-1.120). The overall quality score of the studies was modest. Conclusions: We demonstrated a significant, beneficial effect of t-PBM on cognitive performance of young, healthy individuals; however, the heterogeneity of the data was high. This could be due to the modest quality or to the low number of included studies, or to the differences between the various subdomains assessed. These shortcomings should be meticulously addressed before concluding that t-PBM is a cognitive-enhancing intervention in healthy individuals.
AB - Background: Transcranial photobiomodulation (t-PBM) is a noninvasive modality that may improve cognitive function in both healthy and diseased subjects. Objective: This systematic review and meta-analysis addresses the question of whether t-PBM improves cognitive function in healthy adults. Methods: We searched MEDLINE using PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Library up to March 2019. We also searched ProQuest and Google Scholar databases for unpublished material. The search was limited to articles on the procognitive effects of t-PBM in healthy adults. The initial search resulted in 871 studies, of which nine publications met our criteria for inclusion and exclusion. Seven studies were performed on young, healthy subjects (17-35 years), and two studies were conducted on older (≥49 years), normal subjects. A meta-analysis was performed on six full-text publications whose subjects were young adults. Results: t-PBM administration improved cognition-related outcomes by an 0.833 standardized mean difference (SMD; 95% confidence interval (CI): 0.458-1.209, 14 comparisons) in young, healthy participants. Funnel plotting revealed asymmetry, which was validated using Egger's (p = 0.030) and Begg's regression (p = 0.006) tests. However after reanalysis, this asymmetry disappeared in the attention subgroup, but not in the memory subgroup. The trim-and-fill analysis indicated two studies were lacking required data. Thus, the effect size was adjusted from an SMD of 0.761 (95% CI: 0.573-0.949) to 0.949 (0.779-1.120). The overall quality score of the studies was modest. Conclusions: We demonstrated a significant, beneficial effect of t-PBM on cognitive performance of young, healthy individuals; however, the heterogeneity of the data was high. This could be due to the modest quality or to the low number of included studies, or to the differences between the various subdomains assessed. These shortcomings should be meticulously addressed before concluding that t-PBM is a cognitive-enhancing intervention in healthy individuals.
KW - attention
KW - cognition
KW - healthy adults
KW - learning
KW - memory
KW - transcranial photobiomodulation
UR - http://www.scopus.com/inward/record.url?scp=85074118227&partnerID=8YFLogxK
U2 - 10.1089/photob.2019.4673
DO - 10.1089/photob.2019.4673
M3 - Article
C2 - 31549906
AN - SCOPUS:85074118227
SN - 2578-5478
VL - 37
SP - 635
EP - 643
JO - Photobiomodulation, Photomedicine, and Laser Surgery
JF - Photobiomodulation, Photomedicine, and Laser Surgery
IS - 10
ER -