RT Journal Article SR Electronic T1 Metacognitive insight into cognitive performance in Huntington’s disease gene carriers JF BMJ Neurology Open JO BMJ Neurol Open FD BMJ Publishing Group Ltd SP e000268 DO 10.1136/bmjno-2022-000268 VO 4 IS 1 A1 Samuel RC Hewitt A1 Alice J White A1 Sarah L Mason A1 Roger A Barker YR 2022 UL http://neurologyopen.bmj.com/content/4/1/e000268.abstract AB Objectives Insight is an important predictor of quality of life in Huntington’s disease and other neurodegenerative conditions. However, estimating insight with traditional methods such as questionnaires is challenging and subjected to limitations. This cross-sectional study experimentally quantified metacognitive insight into cognitive performance in Huntington’s disease gene carriers.Methods We dissociated perceptual decision-making performance and metacognitive insight into performance in healthy controls (n=29), premanifest (n=19) and early-manifest (n=10) Huntington’s disease gene carriers. Insight was operationalised as the degree to which a participant’s confidence in their performance was informative of their actual performance (metacognitive efficiency) and estimated using a computational model (HMeta-d’).Results We found that premanifest and early-manifest Huntington’s disease gene carriers were impaired in making perceptual decisions compared with controls. Gene carriers required more evidence in favour of the correct choice to achieve similar performance and perceptual impairments were increased in those with manifest disease. Surprisingly, despite marked perceptual impairments, Huntington’s disease gene carriers retained metacognitive insight into their perceptual performance. This was the case after controlling for confounding variables and regardless of disease stage.Conclusion We report for the first time a dissociation between impaired cognition and intact metacognition (trial-by-trial insight) in the early stages of a neurodegenerative disease. This unexpected finding contrasts with the prevailing assumption that cognitive deficits are associated with impaired insight. Future studies should investigate how intact metacognitive insight could be used by some early Huntington’s disease gene carriers to positively impact their quality of life.Data are available in a public, open access repository. Anonymised clinical and demographic information, task data, model outputs and scripts used for analysis are available on Github (https://github.com/samrchewitt/HD_perception_metacognition). These are shared under Creative Commons Zero v1.0 Universal license.