Repeated transcranial photobiomodulation improves working memory of healthy older adults: behavioral outcomes of poststimulation including a three-week follow-up

Xiujuan Qu; Lexuan Li; Xiaohan Zhou; Qi Dong; Hanli Liu; Hesheng Liu; Qin Yang; Ying Han; Haijing Niu

doi:10.1117/1.NPh.9.3.035005

27 September 2022 Repeated transcranial photobiomodulation improves working memory of healthy older adults: behavioral outcomes of poststimulation including a three-week follow-up

Xiujuan Qu, Lexuan Li, Xiaohan Zhou, Qi Dong, Hanli Liu, Hesheng Liu, Qin Yang, Ying Han, Haijing Niu

Author Affiliations +

Neurophotonics, Vol. 9, Issue 3, 035005 (September 2022). https://doi.org/10.1117/1.NPh.9.3.035005

Abstract

Significance

Decline in cognitive ability is a significant issue associated with healthy aging. Transcranial photobiomodulation (tPBM) is an emerging non-invasive neuromodulation technique and has shown promise to overcome this challenge.

Aim

This study aimed to investigate the effects of seven-day repeated tPBM, compared to those of single tPBM and baseline, on improving N-back working memory in healthy older adults and to evaluate the persistent efficacy of repeated tPBM.

Approach

In a sham-controlled and within-subject design, 61 healthy older adults were recruited to participate in a longitudinal study involving an experimental baseline, seven days of tPBM treatment (12 min daily, 1064-nm laser, 250 mW / cm²) in the left dorsolateral prefrontal cortex and three weeks of follow-ups. Behavioral performance in the N-back (N = 1,2 , 3) was recorded poststimulation during the baseline, the first and seventh days of the tPBM session, and the three weekly follow-ups. A control group with 25 participants was included in this study to rule out the practice and placebo effects. The accuracy rate and response time were used in the statistical analysis.

Results

Repeated and single tPBM significantly improved accuracy rate in 1- and 3-back tasks and decreased response time in 3-back compared to the baseline. Moreover, the repeated tPBM resulted in a significantly higher improvement in accuracy rate than the single tPBM. These improvements in accuracy rate and response time lasted at least three weeks following repeated tPBM. In contrast, the control group showed no significant improvement in behavioral performance.

Conclusions

This study demonstrated that seven-day repeated tPBM improved the working memory of healthy older adults more efficiently, with the beneficial effect lasting at least three weeks. These findings provide fundamental evidence that repeated tPBM may be a potential intervention for older individuals with memory decline.

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Citation Download Citation

Xiujuan Qu, Lexuan Li, Xiaohan Zhou, Qi Dong, Hanli Liu, Hesheng Liu, Qin Yang, Ying Han, and Haijing Niu "Repeated transcranial photobiomodulation improves working memory of healthy older adults: behavioral outcomes of poststimulation including a three-week follow-up," Neurophotonics 9(3), 035005 (27 September 2022). https://doi.org/10.1117/1.NPh.9.3.035005

Received: 16 May 2022; Accepted: 12 September 2022; Published: 27 September 2022

ACCESS THE FULL ARTICLE

JOURNAL ARTICLE
12 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY