Serge Brédart

Characteristics of Near-Death Experiences Memories as Compared to Real and Imagined Events Memories

Since the dawn of time, Near-Death Experiences (NDEs) have intrigued and, nowadays, are still not fully explained. Since reports of NDEs are proposed to be imagined events, and since memories of imagined events have, on average, fewer phenomenological characteristics than real events memories, we here compared phenomenological characteristics of NDEs reports with memories of imagined and real events. We included three groups of coma survivors (8 patients with NDE as defined by the Greyson NDE scale, 6 patients without NDE but with memories of their coma, 7 patients without memories of their coma) and a group of 18 age-matched healthy volunteers. Five types of memories were assessed using Memory Characteristics Questionnaire (MCQ – Johnson et al., 1988): target memories (NDE for NDE memory group, coma memory for coma memory group, and first childhood memory for no memory and control groups), old and recent real event memories and old and recent imagined event memories. Since NDEs are known to have high emotional content, participants were requested to choose the most emotionally salient memories for both real and imagined recent and old event memories. Results showed that, in NDE memories group, NDE memories have more characteristics than memories of imagined and real events (p<0.02). NDE memories contain more self-referential and emotional information and have better clarity than memories of coma (all ps<0.02). The present study showed that NDE memories contained more characteristics than real event memories and coma memories. Thus, this suggests that they cannot be considered as imagined event memories. On the contrary, their physiological origins could lead them to be really perceived although not lived in the reality. Further work is needed to better understand this phenomenon.

Looking for the self in pathological unconsciousness.

There is an intimate relationship between consciousness and the notion of self. By studying patients with disorders of consciousness, we are offered with a unique lesion approach to tackle the neural correlates of self in the absence of subjective reports. Studies employing neuroimaging techniques point to the critical involvement of midline anterior and posterior cortices in response to the passive presentation of self-referential stimuli, such as the patient’s own name and own face. Also, resting state studies show that these midline regions are severely impaired as a function of the level of consciousness. Theoretical frameworks combining all this progress surpass the functional localization of self-related cognition and suggest a dynamic system-level approach to the phenomenological complexity of subjectivity. Importantly for non-communicating patients suffering from disorders of consciousness, the clinical translation of these technologies will allow medical professionals and families to better comprehend these disorders and plan efficient medical management for these patients.

Evidence for an own-age bias in age estimation from voices in older persons

Previous studies have investigated the effect of ageing on age estimation from faces as well as the occurrence of an own-age bias in such age estimation from faces. To the best of our knowledge, the occurrence of an own age effect on age estimation from voices has never been examined earlier using an experimental design in which the age of participants (young vs. old) and the age of voice stimuli (young vs. old) were crossed. Results revealed an own-age bias in older adults only. In comparison with younger adults, older participants showed age estimation abilities that are preserved for voices from their own age group and impaired for younger voices. This own age bias was absent in younger participants.

Impairment of age estimation from faces in Alzheimer’s disease

A prerequisite for any function in social cognition is the perception and processing of social cues. Age estimation is a skill that is used in everyday life and is fundamental in social interactions. This study evaluated whether facial age estimation is impaired in patients with mild to moderate Alzheimers disease (AD). The current age of faces is known to have an impact on age estimation, and therefore stimuli belonging to different age groups (young, middle-aged, and older adults faces) were used. As expected, an impairment of age estimation from faces was observed in mild to moderate AD patients. However, the profile of impairment depended on the age of faces and stage of the disease. Mild AD patients presented difficulties mainly in assessing the age of middle-aged adults. In moderate disease stage, these difficulties also affected the age estimation of young adult faces. Interestingly, AD patients remained relatively good at estimating the age of older adults faces, compared to healthy controls.

Similarities between the target and the intruder in naturally occurring repeated person naming errors.

The present study investigated an intriguing phenomenon that did not receive much attention so far: repeatedly calling a familiar person with someone else’s name. From participants’ responses to a questionnaire, these repeated naming errors were characterized with respect to a number of properties (e.g., type of names being substituted, error frequency, error longevity) and different features of similarity (e.g., age, gender, type of relationship with the participant, face resemblance and similarity of the contexts of encounter) between the bearer of the target name and the bearer of the wrong name. Moreover, it was evaluated whether the phonological similarity between names, the participants’ age, the difference of age between the two persons whose names were substituted, and face resemblance between the two persons predicted the frequency of error. Regression analyses indicated that phonological similarity between the target name and the wrong name predicted the frequency of repeated person naming errors. The age of the participant was also a significant predictor of error frequency: the older the participant the higher the frequency of errors. Consistent with previous research stressing the importance of the age of acquisition of words on lexical access in speech production, results indicated that bearer of the wrong name was on average known for longer than the bearer of the target name.

Verbal overshadowing of face memory does occur in children too

Verbal descriptions of unfamiliar faces have been found to impair later identification of these faces in adults, a phenomenon known as the “verbal overshadowing effect” (VOE). Although determining whether children are good at describing unfamiliar individuals and whether these descriptions impair their recognition performance is critical to gaining a better understanding childrens eyewitness ability, only a couple of studies have examined this dual issue in children and these found no evidence of VOE. However, as there are some methodological criticisms of these studies, we decided to conduct two further experiments in 7–8, 10–11, and 13–14-year-old children and in adults using a more optimal method for the VOE to be observed. Evidence of the VOE on face identification was found in both children and adults. Moreover, neither the accuracy of descriptions, nor delay nor target presence in the lineup was found to be associated with identification accuracy. The theoretical and developmental implications of these findings are discussed.

Mirror efficiency in the assessment of visual pursuit in patients in minimally conscious state.

ABSTRACT Objective: Visual pursuit should be tested with a mirror in patients with disorders of consciousness. This stimulus was indeed more efficient than a person or an object, and the auto-referential aspect was supposed to be the key feature. The present study tested the hypothesis that the mirror was more efficient because of its self-aspect. Methods: The mirror was compared (1) to the patient’s picture and to the picture of a famous face, in 22 patients in minimally conscious state and (2) to the patient’s picture and a fake mirror, which had dynamical and bright aspects of the mirror, without reflecting the face, in 26 other patients in minimally conscious state. Results: The mirror was more efficient than the patient’s picture, which was not statistically different from the famous face. The second part of the study confirmed the statistical difference between the mirror and the picture. However, the fake mirror was neither statistically different from the mirror nor from the picture. Conclusions: Although our results suggest that the hypothesis proposed by previous studies was partly wrong, they confirm that the mirror is the best stimulus to use when assessing visual pursuit.

The cognitive psychology and neuroscience of naming people

HighlightsReview of cognitive and neurocognitive studies of proper name production.Proper names are harder to recall than common nouns.Proper name recall recruits a partially specific network of brain regions.Concrete directions for future research are presented. Abstract The use of proper names enables us to designate entities, including people, at a very specific level of categorization: the unique entity or the individual. The paper presents a general overview of psychological/cognitive and neuroscientific studies that have compared the production of proper names, in particular people’s names, with the production of common nouns during the last thirty years. The search for specific brain correlates of proper naming included single‐case and group studies of patients with brain lesions, and studies utilizing functional neuroimaging or brain electrical stimulation with healthy participants. These studies have led neuroscientists to hypothesize that the recall of proper names involves a rather complex network including mainly left frontal and temporal regions. Behavioural evidence supports the view that proper names are more difficult to recall than common names, and scientists have proposed different explanations for this relative difficulty. Finally, several new directions for future research are proposed to improve our understanding of both cognitive processes and their brain correlates involved during proper name recall.

A Self-Reference Effect on Memory for People: We Are Particularly Good at Retrieving People Named Like Us.

In the present study, it was evaluated whether one’s own name may produce a self-reference bias in memory for people. Results from Experiment 1 indicated that, in a verbal fluency task, participants recalled a greater number of known (familiar or famous) people with the same first name as their own than did paired participants, and vice versa. In the first experiment, paired participants knew each other but were not close. Experiment 2 examined whether this self-reference effect would still occur when the comparison target was a close other. This experiment showed that such a self-reference bias also occurred even when the paired persons were close (partners or very good friends). Overall the present paper describes a new naturalistic case of the self-reference effect.

The effect of spontaneous self-reference on memory: a replication

Resume n L’objectif de cette etude etait de tenter de reproduire les resultats de Kesebir et Oichi (Psychological Science, 21, 1525-1532, 2010) qui ont decrit un effet d’autoreference spontane pour la memoire des mois d’anniversaire de 4 personnes dont une etait nee le meme mois que le participant. Nous avons reproduit cet effet en utilisant d’abord la meme variable dependante qu’euxxa0: la distance moyenne (en mois) entre le mois de l’anniversaire du participant et les mois qu’il pouvait rappeler etait plus petite que la distance moyenne entre le mois de naissance du participant et les mois qu’il ne pouvait pas rappeler. En outre, l’effet d’autoreference a aussi ete mis en evidence en examinant une autre mesure a savoir la proportion de rappels corrects des mois de naissance. La proportion de rappels corrects etait superieure pour les personnes qui etaient nees le meme mois que le participant que pour celles qui etaient nees un mois different.