*EASTBIO* Neurophysiological markers of memory error monitoring across the lifespan

BBSRC Theme: Word class underpinning Bioscience

Adaptive cognition involves both the completion of a set of mental operations and the awareness that these operations have been completed so that the next stage of cognition can be engaged. During successful memory decision-making these two steps, memory retrieval and retrieval awareness, go hand in hand. However, they can occasionally fragment, leading to a set of experiences termed introspective memory phenomena (IMPs; e.g. déjà vu and jamais vu). During déjà vu positive retrieval awareness arises in the absence of true retrieval, yielding the overall sensation of inappropriate familiarity (O’Connor & Moulin, 2010). Jamais vu is the opposite–negative retrieval awareness in the presence of true retrieval. IMPs signal conflict within the cognitive system, and thus may play a crucial role in error correction (we do not act on IMPs in the way that we do act on false memories). However, beyond some curious demographic associations (they occur more in those who are well-travelled and well-educated), IMP occurrence is not known to be associated with any existing cognitive or psychological traits.

IMPs are not experienced uniformly across the population but peak in those in their mid-20s, before declining with age thereafter. They are also thought to be driven by dopaminergic over-activity such that some pharmacological and recreational drugs (e.g. dopaminergic flu medications) have been reported as causing persistent déjà vu (Taiminen & Jääskeläinen, 2001). Interestingly, these characteristics mirror what is known about neurophysiological markers of inhibitory control and response monitoring more generally (e.g. Strozyk & Jentzsch, 2012), which show the same lifespan trajectory with an age-related decrease in the dopaminergic functions mediated by the frontal cortex. These links suggest that IMP occurrence may be underpinned by basic neurocognitive characteristics integral to healthy cognition. Thus, the importance of IMPs may not lie in the fragmentation of the memory decision-making system, but in the capacity for our response monitoring systems to detect it and stop us making decisions based on faulty information.

We propose a systematic programme of research to establish the role of error-monitoring in the generation of IMPs. Using i) retrospective questioning to verify the recent occurrence of IMPs and ii) established procedures for their laboratory generation, we will explore individual differences in IMP experience and neurophysiological markers of response monitoring. These experiments will be a) developed in young adults and extended to b) primary school children (age 8-11; the age at which IMPs are first reported by children) and c) older adults (age 55 and older). We will also conduct opportunistic case-studies on d) patients who present themselves to Dr O’Connor over the course of the PhD (UK-based patients typically get in touch at a rate of 1-2/year). This systematic programme will allow us to establish any potential links between basic neurocognitive characteristics and the tendency to experience dissociative memory sensations which are not known to have any other psychological correlates.

This project will benefit from the joint multi-disciplinary expertise of Dr O’Connor, an internationally recognized expert in the area of metacognition and introspective memory phenomena and Dr Jentzsch, a biophysicist and electrophysiologist by training, who specialized in studying the neural underpinnings dopaminergic functions such as action and conflict control. Together, we will provide the prospective student conceptual knowledge of metacognitive models of memory and changes to these functions with healthy ageing integrating behavioural methods and physiological measures of brain function in humans. The student will learn about experimental design, programming (Matlab), data collection and behavioural analysis techniques such as signal detection theory. In addition, the student will learn how to design, conduct and analyse electrophysiological experiments using EEG. Acquisition of generic skills such as team-working, time-management and communication skills amongst many others will also be an important part of the students training.