Subliminal linguistic effects occur when words or phrases that are overheard by an interlocutor become subconsciously assimilated into their ongoing talk. Such effects are a common feature of everyday interaction. Yet by their nature they are ephemeral, extremely difficult to capture empirically and have not previously been studied at the micro-interactional level. However, broader ethnographic observations made in dementia care settings appear to indicate that subliminal linguistic effects are operationalised differently in people who have dementia, when compared to those without cognitive problems. This exploratory study focuses on over 200 hours of naturalistic multiparty field recordings collected in two UK dementia care settings. It utilises conversation analysis (CA) to examine the reproduction of naturally occurring subliminal linguistic effects in the speech and communication patterns of people with dementia and provides the first systematic micro-analysis of the phenomenon. The position of subliminal linguistic effects in relation to existing sociolinguistic research on overhearing and repetition and the role that features such as intonational emphasis may play in generating subliminal cues are discussed. The study confirms that it is possible to capture examples of subliminal linguistic effects in naturalistic settings and that there are potentially a number of micro-interactional features associated with the phenomenon in dementia communication which could form the basis of a novel, non-intrusive measure of cognitive impairment.