© Cambridge University Press 2019. Cognitive decline and dementia have become major concerns for many individuals reaching later life within contemporary Western societies. This fear of decline is central to the social divide between the third age embodying ideals of maintained health, activity and lifestyle choices, and the fourth age, a social imaginary encompassing the irreversible decline associated with ageing. In this article, we explore how brain-training technologies have become successful by relying on tensions between the third and fourth ages. We review current debates on the concepts contained in brain training and examine the emphasis on the moral virtue of 'training the brain' in later life as an extension of fitness and health management. We underline the limited consideration given to social positioning within old age itself in the literature. We further argue that using brain-training devices can support a distancing from intimations of dementia; a condition associated with an 'ageing without agency'. Drawing on Bourdieu, we use the concept of distinction to describe this process of social positioning. We discuss the impact that such 'technologies of distinction' can have on people with dementia by 'othering' them. We conclude that the issue of distinction within later life, particularly within the field of cognitive decline, is an important aspect of the current culture of active cognitive ageing.