title: Effect of acute hypoxia on cognition: A systematic review and meta-regression analysis.
abstract: A systematic meta-regression analysis of the effects of acute hypoxia on the performance of central executive and non-executive tasks, and the effects of the moderating variables, arterial partial pressure of oxygen (PaO2) and hypobaric versus normobaric hypoxia, was undertaken. Studies were included if they were performed on healthy humans; within-subject design was used; data were reported giving the PaO2or that allowed the PaO2to be estimated (e.g. arterial oxygen saturation and/or altitude); and the duration of being in a hypoxic state prior to cognitive testing was ≤6days. Twenty-two experiments met the criteria for inclusion and demonstrated a moderate, negative mean effect size (g=-0.49, 95% CI -0.64 to -0.34, p<0.001). There were no significant differences between central executive and non-executive, perception/attention and short-term memory, tasks. Low (35-60mmHg) PaO2was the key predictor of cognitive performance (R2=0.45, p<0.001) and this was independent of whether the exposure was in hypobaric hypoxic or normobaric hypoxic conditions.
authors.affiliation: Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Guildhall Walk, Portsmouth PO1 2ER, United Kingdom; Department Sport and Exercise Science, Institute for Sport, University of Chichester, College Lane, Chichester, West Sussex PO19 6PE, United Kingdom; Depaertment of Psyhcology, Facultuy of Health and Life Sciences, Northumbria University, Northumberland Road, Newcastle-upon-Tyne NE1 8ST, United Kingdom. Electronic address: t.mcmorris@chi.ac.uk.
authors.forename: Terry
authors.initials: T
authors.lastname: McMorris
authors.affiliation: Department Sport and Exercise Science, Institute for Sport, University of Chichester, College Lane, Chichester, West Sussex PO19 6PE, United Kingdom.
authors.forename: Beverley J
authors.initials: BJ
authors.lastname: Hale
authors.affiliation: Department of Sport, Health and Nutrition, Leeds Trinity University, Brownberrie Lane, Horsforth LS18 5HD, United Kingdom.
authors.forename: Martin
authors.initials: M
authors.lastname: Barwood
authors.affiliation: Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Guildhall Walk, Portsmouth PO1 2ER, United Kingdom.
authors.forename: Joseph
authors.initials: J
authors.lastname: Costello
authors.affiliation: Department of Sport and Exercise Science, Faculty of Science, University of Portsmouth, Guildhall Walk, Portsmouth PO1 2ER, United Kingdom.
authors.forename: Jo
authors.initials: J
authors.lastname: Corbett
mesh_terms: D000208:Acute Disease; D000531:Altitude; D003071:Cognition; D006801:Humans; D000860:Hypoxia; D010100:Oxygen; D012044:Regression Analysis
chemical_list: D010100:Oxygen
keywords: Arterial partial pressure of oxygen; Carotid body; Catecholamines; Central executive; Glossypharyngeal nerve; Hypobaric; Internal carotid arteries; Normobaric; Perception; Regional cerebral blood flow; Short-term memory; Vertebral arteries