Look into my eyes: What can eye-based measures tell us about the relationship between physical activity and cognitive performance?

Liye Zou; Fabian Herold; Sebastian Ludyga; Keita Kamijo; Notger G Müller; Matthew B Pontifex; Matthew Heath; Ryuta Kuwamizu; Hideaki Soya; Charles H Hillman; Soichi Ando; Brandon L Alderman; Boris Cheval; Arthur F Kramer

doi:10.1016/j.jshs.2023.04.003

Look into my eyes: What can eye-based measures tell us about the relationship between physical activity and cognitive performance?

J Sport Health Sci. 2023 Sep;12(5):568-591. doi: 10.1016/j.jshs.2023.04.003. Epub 2023 May 5.

Authors

Affiliations

¹ Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen 518060, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam 14476, Germany. Electronic address: liyezou123@gmail.com.
² Body-Brain-Mind Laboratory, School of Psychology, Shenzhen University, Shenzhen 518060, China; Research Group Degenerative and Chronic Diseases, Movement, Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam 14476, Germany.
³ Department of Sport, Exercise, and Health, University of Basel, Basel 4052, Switzerland.
⁴ Faculty of Liberal Arts and Sciences, Chukyo University, Nagoya 466-8666, Japan.
⁵ Department of Kinesiology, Michigan State University, East Lansing, MI 48824, USA.
⁶ School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London ON N6A 3K7, Canada; Canadian Centre for Activity and Aging, University of Western Ontario, London ON, N6A 3K7, Canada; Graduate Program in Neuroscience, University of Western Ontario, London ON, N6A 3K7, Canada.
⁷ Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan.
⁸ Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan; Sport Neuroscience Division, Advanced Research Initiative for Human High Performance (ARIHHP), Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-0006, Japan.
⁹ Center for Cognitive and Brain Health, Department of Psychology, Department of Physical Therapy, Movement, and Rehabilitation Sciences, Northeastern University, Boston, MA 02115, USA.
¹⁰ Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo 182-8585, Japan.
¹¹ Department of Kinesiology and Health, Rutgers University-New Brunswick, New Brunswick, NJ 08854, USA.
¹² Swiss Center for Affective Sciences, University of Geneva, Geneva 1205, Switzerland; Laboratory for the Study of Emotion Elicitation and Expression (E3Lab), Department of Psychology, University of Geneva, Geneva 1205, Switzerland.
¹³ Department of Psychology, Center for Cognitive and Brain Health, Northeastern University, Boston, MA 02115, USA; Beckman Institute, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA.

Abstract

Background: There is a growing interest to understand the neurobiological mechanisms that drive the positive associations of physical activity and fitness with measures of cognitive performance. To better understand those mechanisms, several studies have employed eye-based measures (e.g., eye movement measures such as saccades, pupillary measures such as pupil dilation, and vascular measures such as retinal vessel diameter) deemed to be proxies for specific neurobiological mechanisms. However, there is currently no systematic review providing a comprehensive overview of these studies in the field of exercise-cognition science. Thus, this review aimed to address that gap in the literature.

Methods: To identify eligible studies, we searched 5 electronic databases on October 23, 2022. Two researchers independently extracted data and assessed the risk of bias using a modified version of the Tool for the assEssment of Study qualiTy and reporting in EXercise (TESTEX scale, for interventional studies) and the critical appraisal tool from the Joanna Briggs Institute (for cross-sectional studies).

Results: Our systematic review (n = 35 studies) offers the following main findings: (a) there is insufficient evidence available to draw solid conclusions concerning gaze-fixation-based measures; (b) the evidence that pupillometric measures, which are a proxy for the noradrenergic system, can explain the positive effect of acute exercise and cardiorespiratory fitness on cognitive performance is mixed; (c) physical training- or fitness-related changes of the cerebrovascular system (operationalized via changes in retinal vasculature) are, in general, positively associated with cognitive performance improvements; (d) acute and chronic physical exercises show a positive effect based on an oculomotor-based measure of executive function (operationalized via antisaccade tasks); and (e) the positive association between cardiorespiratory fitness and cognitive performance is partly mediated by the dopaminergic system (operationalized via spontaneous eye-blink rate).

Conclusion: This systematic review offers confirmation that eye-based measures can provide valuable insight into the neurobiological mechanisms that may drive positive associations between physical activity and fitness and measures of cognitive performance. However, due to the limited number of studies utilizing specific methods for obtaining eye-based measures (e.g., pupillometry, retinal vessel analysis, spontaneous eye blink rate) or investigating a possible dose-response relationship, further research is necessary before more nuanced conclusions can be drawn. Given that eye-based measures are economical and non-invasive, we hope this review will foster the future application of eye-based measures in the field of exercise-cognition science.

Keywords: Cognition; Exercise; Fitness; Pupil size; Retina.

Publication types

Systematic Review
Review

MeSH terms

Cardiorespiratory Fitness*
Cognition / physiology
Cross-Sectional Studies
Exercise* / physiology
Physical Examination