VL: a further case of erroneous recollection

Memory, aging and the brain: Old findings and current issues

In this article I reprise some selected findings and issues from my previous behavioural work on age-related differences in memory, and relate them to current work on the neural correlates of encoding, retrieval and representation. In particular, I describe the case study of a woman who had persistent experiences of erroneous recollection. I also describe the results of a study showing a double dissociation of implicit and explicit memory in younger and older adults. Finally, I assess recent work on loss of specificity in older adults' encoding and retrieval processes of episodic events. In all cases I attempt to relate these older findings to current ideas and empirical results in the area of memory, aging, and the brain.

Déjà vécu with recollective confabulation: an unusual presentation of Alzheimer's disease

A man in his 80s presented with gradual onset of a persistent and delusion-like perception that novel encounters are repetitions of previous experiences. Within 2 years of symptom onset, he had impaired verbal memory and executive dysfunction on neuropsychological assessment. Cerebrospinal fluid core Alzheimer's disease (AD) biomarkers analysis supported probable AD. Generalised and left temporal atrophy was seen on MRI of the brain. Neurological fludeoxyglucose-positron emission tomography (PET)/CT showed left temporal and bilateral frontal lobe hypometabolism. His presenting symptom is known as déjà vécu with recollective confabulation, a rare phenomenon associated with AD and other neurodegenerative disorders. While several potential mechanisms have been previously proposed, the fludeoxyglucose-PET/CT hypometabolism in the temporal and frontal lobes in this case suggests dual deficits in recognition memory and metacognition may be culprit mechanisms. Although uncommon, déjà vécu with recollective confabulation is a fascinating phenomenon that can provide a unique insight into memory and delusional processes in dementia.

Are involuntary autobiographical memory and déjà vu natural products of memory retrieval?

Involuntary autobiographical memories (IAMs) and déjà vu are phenomena that occur spontaneously in daily life. IAMs are recollections of the personal past, whereas déjà vu is defined as an experience in which the person feels familiarity at the same time as knowing that the familiarity is false. We present and discuss the idea that both IAMs and déjà vu can be explained as natural phenomena resulting from memory processing and, importantly, are both based on the same memory retrieval processes. Briefly, we hypothesise that both can be described as "involuntary" or spontaneous cognitions, where IAMs deliver content and déjà vu delivers only the feeling of retrieval. We map out the similarities and differences between the two, making a theoretical and neuroscientific account for their integration into models of memory retrieval and how the autobiographical memory literature can explain these quirks of daily life and unusual but meaningful phenomena. We explain the emergence of the déjà vu phenomenon by relating it to well-known mechanisms of autobiographical memory retrieval, concluding that IAMs and déjà vu lie on a continuum.

History repeating itself: Arnaud's case of pathological déjà vu

We present a translation of Arnaud's (1896) case report of Patient Louis, a case he describes as having a pathological form of déjà vu. Louis has the delusional belief that the present moment is a repetition of an exact same previous event. Arnaud's paper is critical for two reasons. Firstly, it is amongst the first articles in the scientific literature to describe the déjà vu experience using the term 'déjà vu'. Secondly, the case report of someone with delusional and persistent déjà vu, anticipates recently reported cases with similar symptoms, which are beginning to gain interest as a particular form of memory disorder. We offer a contemporary analysis of Louis and conclude that, whilst the article was critical in the development of déjà vu as a scientific concern, Louis's distorted memory is not best described as déjà vu, but rather as a form of reduplicative paramnesia described as recollective confabulation.