{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,8]],"date-time":"2026-08-08T19:54:33Z","timestamp":1786218873486,"version":"build-2736575974"},"reference-count":54,"publisher":"Public Library of Science (PLoS)","issue":"11","license":[{"start":{"date-parts":[[2025,11,24]],"date-time":"2025-11-24T00:00:00Z","timestamp":1763942400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"NSERC","doi-asserted-by":"crossref","award":["Discovery Grant"],"award-info":[{"award-number":["Discovery Grant"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100015569","name":"CCNA","doi-asserted-by":"crossref","award":["Sex and Gender Team 9 Award"],"award-info":[{"award-number":["Sex and Gender Team 9 Award"]}],"id":[{"id":"10.13039\/100015569","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/100015569","name":"CCNA","doi-asserted-by":"crossref","award":["Sex and Gender Team 9 Award"],"award-info":[{"award-number":["Sex and Gender Team 9 Award"]}],"id":[{"id":"10.13039\/100015569","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Despite sex-based differences in age-related diseases and life expectancy, limited research has explicitly examined sex differences in aging. Longitudinal study designs are particularly underutilized. The current study retrieved longitudinal data from the healthy control group of the Parkinson\u2019s Progression Markers Initiative to examine baseline differences and cognitive changes in males and females over time.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Male (n\u2009=\u2009125, mean age\u2009=\u200961.61) and female (n\u2009=\u200968, mean age\u2009=\u200959.44) participants completed neuropsychological measures annually for up to five years. Measures included the Montreal Cognitive Assessment (MoCA), Letter Number Sequencing (LNS), Semantic Fluency (SFT), Symbol Digit Modalities Test (SDMT), Benton Judgment of Line Orientation Test (BJLOT), Hopkins Verbal Learning Test-Revised Immediate and Delayed Recall (HVLT-R). Within-person changes in cognition and between-group differences longitudinal change trajectories as predicted by sex were examined in a hierarchical fashion. Effects of age and education were also examined.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>At baseline, females had higher scores on the SFT, SDMT, and the HVLT-R Immediate and Delayed Recall, while males had higher scores on the BJLOT. However, rates of change in cognition over time did not significantly differ by sex. Higher baseline age predicted lower scores for all neuropsychological outcome measures, and higher education predicted higher scores for all neuropsychological outcome measures except for the MoCA.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Although there were sex differences in certain domains of cognitive function, rates of cognitive change over time did not significantly differ by sex. Intraindividual variability in cognitive trajectories of aging was observed. Future research should examine factors that predict individual trajectories of aging in healthy individuals.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0334358","type":"journal-article","created":{"date-parts":[[2025,11,24]],"date-time":"2025-11-24T18:27:07Z","timestamp":1764008827000},"page":"e0334358","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Sex similarities and differences in cognition: A longitudinal study of healthy control participants from the Parkinson Progression Markers Initiative"],"prefix":"10.1371","volume":"20","author":[{"given":"Lisa","family":"Ohlhauser","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heather","family":"Kwan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hayley","family":"Casey","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stuart","family":"MacDonald","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4924-7517","authenticated-orcid":true,"given":"Jodie R.","family":"Gawryluk","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,11,24]]},"reference":[{"key":"pone.0334358.ref001","unstructured":"United Nations, Department of Economic and Social Affairs, Population Division. World population ageing, 2019 highlights. 2020."},{"key":"pone.0334358.ref002","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1016\/j.neubiorev.2021.02.026","article-title":"Dump the \u201cdimorphism\u201d: Comprehensive synthesis of human brain studies reveals few male-female differences beyond size","volume":"125","author":"L Eliot","year":"2021","journal-title":"Neurosci Biobehav Rev"},{"issue":"2","key":"pone.0334358.ref003","doi-asserted-by":"crossref","first-page":"130","DOI":"10.1027\/2151-2604\/a000104","article-title":"Re-Conceptualizing \u201cSex\u201d and \u201cGender\u201d in the Human Brain","volume":"220","author":"A Kaiser","year":"2012","journal-title":"Zeitschrift f\u00fcr Psychologie"},{"key":"pone.0334358.ref004","doi-asserted-by":"crossref","first-page":"650","DOI":"10.3389\/fnhum.2014.00650","article-title":"Recommendations for sex\/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation","volume":"8","author":"G Rippon","year":"2014","journal-title":"Front Hum Neurosci"},{"key":"pone.0334358.ref005","doi-asserted-by":"crossref","first-page":"2827090","DOI":"10.1155\/2016\/2827090","article-title":"Sex and Gender Differences in Central Nervous System-Related Disorders","volume":"2016","author":"E Zagni","year":"2016","journal-title":"Neurosci J"},{"issue":"6","key":"pone.0334358.ref006","doi-asserted-by":"crossref","first-page":"581","DOI":"10.1037\/0003-066X.60.6.581","article-title":"The gender similarities hypothesis","volume":"60","author":"JS Hyde","year":"2005","journal-title":"Am Psychol"},{"issue":"2","key":"pone.0334358.ref007","doi-asserted-by":"crossref","first-page":"307","DOI":"10.3758\/s13423-016-1085-7","article-title":"Sex differences in visual-spatial working memory: A meta-analysis","volume":"24","author":"D Voyer","year":"2017","journal-title":"Psychon Bull Rev"},{"issue":"1","key":"pone.0334358.ref008","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1007\/s10648-012-9215-x","article-title":"A Meta-Analysis on Gender Differences in Mental Rotation Ability Measured by the Purdue Spatial Visualization Tests: Visualization of Rotations (PSVT:R)","volume":"25","author":"Y Maeda","year":"2012","journal-title":"Educ Psychol Rev"},{"issue":"8","key":"pone.0334358.ref009","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1037\/bul0000197","article-title":"What did you do yesterday? A meta-analysis of sex differences in episodic memory","volume":"145","author":"M Asperholm","year":"2019","journal-title":"Psychol Bull"},{"issue":"14","key":"pone.0334358.ref010","doi-asserted-by":"crossref","first-page":"51","DOI":"10.5709\/acp-0238-x","article-title":"Age and Sex Differences in Verbal and Visuospatial Abilities","volume":"2","author":"E Barel","year":"2018","journal-title":"Adv Cogn Psychol"},{"key":"pone.0334358.ref011","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.comppsych.2017.02.008","article-title":"Gender differences of neuropsychological profiles in cognitively normal older people without amyloid pathology","volume":"75","author":"J Zhang","year":"2017","journal-title":"Compr Psychiatry"},{"issue":"1","key":"pone.0334358.ref012","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1111\/ggi.12093","article-title":"Rate of cognitive decline in relation to sex after 60 years-of-age: a systematic review","volume":"14","author":"L Ferreira","year":"2014","journal-title":"Geriatr Gerontol Int"},{"key":"pone.0334358.ref013","doi-asserted-by":"crossref","first-page":"574","DOI":"10.1080\/13825580600678418","article-title":"Sex differences in cognition are stable over a 10-year period in adulthood and old age","volume":"13","author":"CM de Frias","year":"2006","journal-title":"Neuropsychol Dev Cogn B Aging Neuropsychol Cogn"},{"issue":"3","key":"pone.0334358.ref014","doi-asserted-by":"crossref","DOI":"10.1093\/geronb\/57.3.P246","article-title":"Anxiety, cognitive performance, and cognitive decline in normal aging","volume":"57","author":"JL Wetherell","year":"2002","journal-title":"J Gerontol B Psychol Sci Soc Sci"},{"issue":"3","key":"pone.0334358.ref015","doi-asserted-by":"crossref","DOI":"10.1093\/geronb\/59.3.P130","article-title":"The extent of stability and change in episodic and semantic memory in old age: demographic predictors of level and change","volume":"59","author":"M L\u00f6vd\u00e9n","year":"2004","journal-title":"J Gerontol B Psychol Sci Soc Sci"},{"issue":"2","key":"pone.0334358.ref016","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1037\/pag0000070","article-title":"Sex differences in cognitive trajectories in clinically normal older adults.","volume":"31","author":"AC McCarrey","year":"2016","journal-title":"Psychol Aging"},{"issue":"4","key":"pone.0334358.ref017","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1016\/j.cger.2013.07.002","article-title":"Normal Cognitive Aging","volume":"29","author":"CN Harada","year":"2013","journal-title":"Clin Geriatric Med"},{"key":"pone.0334358.ref018","unstructured":"Government of Canada. What is gender? What is sex? - Candian Institutes of Health Research. 10 Jan 2014 [cited 1 May 2020]. Available from: https:\/\/cihr-irsc.gc.ca\/e\/48642.html"},{"key":"pone.0334358.ref019","unstructured":"World Health Organization. Gender and health [cited 9 Jun 2022]. Available from: http:\/\/www.who.int\/health-topics\/gender"},{"key":"pone.0334358.ref020","unstructured":"Bates D, Maechler M, Bolker aut B, cre, Walker S, Christensen RHB, et al. lme4: Linear Mixed-Effects Models using \u201cEigen\u201d and S4. 2022. Available from: https:\/\/CRAN.R-project.org\/package=lme4"},{"issue":"1","key":"pone.0334358.ref021","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1186\/s12874-019-0876-8","article-title":"LEVEL (Logical Explanations & Visualizations of Estimates in Linear mixed models): recommendations for reporting multilevel data and analyses","volume":"20","author":"MJ Monsalves","year":"2020","journal-title":"BMC Med Res Methodol"},{"issue":"3","key":"pone.0334358.ref022","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0213948","article-title":"Age and cognitive decline in the UK Biobank","volume":"14","author":"MC Cornelis","year":"2019","journal-title":"PLoS One"},{"issue":"11","key":"pone.0334358.ref023","doi-asserted-by":"crossref","first-page":"1777","DOI":"10.1212\/01.WNL.0000065892.67099.2A","article-title":"Gender, cognitive decline, and risk of AD in older persons","volume":"60","author":"LL Barnes","year":"2003","journal-title":"Neurology"},{"issue":"4","key":"pone.0334358.ref024","doi-asserted-by":"crossref","DOI":"10.1093\/geronb\/61.4.P245","article-title":"Stability of sex differences in cognition in advanced old age: the role of education and attrition","volume":"61","author":"D Gerstorf","year":"2006","journal-title":"J Gerontol B Psychol Sci Soc Sci"},{"issue":"4","key":"pone.0334358.ref025","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1037\/0278-6133.20.4.243","article-title":"Social relationships, social support, and patterns of cognitive aging in healthy, high-functioning older adults: MacArthur studies of successful aging","volume":"20","author":"TE Seeman","year":"2001","journal-title":"Health Psychol"},{"issue":"2","key":"pone.0334358.ref026","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1037\/0882-7974.18.2.318","article-title":"The fate of cognition in very old age: six-year longitudinal findings in the Berlin Aging Study (BASE)","volume":"18","author":"T Singer","year":"2003","journal-title":"Psychol Aging"},{"key":"pone.0334358.ref027","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1080\/13825580490511044","article-title":"Canadian Study of Health and Aging: Study Description and Patterns of Early Cognitive Decline","volume":"11","author":"I McDowell","year":"2004","journal-title":"Aging Neuropsychol Cognit"},{"issue":"4","key":"pone.0334358.ref028","doi-asserted-by":"crossref","first-page":"1683","DOI":"10.3233\/JAD-215564","article-title":"Test-Retest Reliability and Minimal Detectable Change of Four Cognitive Tests in Community-Dwelling Older Adults","volume":"87","author":"KL Webb","year":"2022","journal-title":"J Alzheimers Dis"},{"issue":"1","key":"pone.0334358.ref029","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1037\/pag0000288","article-title":"Trajectories of normal cognitive aging","volume":"34","author":"TA Salthouse","year":"2019","journal-title":"Psychol 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Strauss","year":"2006","edition":"3"},{"issue":"1","key":"pone.0334358.ref046","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1159\/000074387","article-title":"Gender differences in level and change in cognitive functioning. 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