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

in PLoS ONE (2013), 8(3),

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 ... [more ▼]

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 event 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 memory 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 memory (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 p<0.02). The present study showed that NDE memories contain 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. [less ▲]

Memories of Near-Death experiences are they memories of imagined events?

Poster (2012, October 27)

Background: The phenomenon of Near-Death Experiences (NDEs) has always intrigued but is still not fully explained despite numerous theories and studies. Since reports of NDEs are proposed to be imagined ... [more ▼]

Background: The phenomenon of Near-Death Experiences (NDEs) has always intrigued but is still not fully explained despite numerous theories and studies. Since reports of NDEs are proposed to be imagined events (French, 2001), and since memories of imagined events have, on average, fewer phenomenological characteristics than real event memories (e.g. Johnson et al., 1988), we here compared phenomenological characteristics of NDEs reports with memories of imagined and real events. Methods: We included 3 groups of coma survivors (8 patients with NDE as defined by the Greyson NDE scale – the “NDE memory group”- , 6 patients without NDE but with memory of their coma – the “coma memory group” – and 7 patients without memories of their coma – the “no memory group”) and a group of 18 age-matched healthy volunteers. Five memories were assessed using Memory Characteristics Questionnaire (MCQ – Johnson et al., 1988): target memory (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. Results: In NDE group, NDE memories showd more characteristics than memories of imagined and real events (p<0.02). These memories contain more self-referential and emotional information and have better clarity than memories of coma (all p<0.02). Conclusion: The present study showed that NDE memories contain more characteristics than real event memories and coma memories. Thus, they cannot be considered as classic 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 [less ▲]

The role of distinctiveness in person recognition from faces and voices

Conference (2012, August 30)

Objectives: When we recognize a familiar person, we can retrieve different kinds of information about her/him: semantic information (e.g. the person’s occupation), episodic information, such as a memory ... [more ▼]

Objectives: When we recognize a familiar person, we can retrieve different kinds of information about her/him: semantic information (e.g. the person’s occupation), episodic information, such as a memory of a specific occasion on which this person has previously been encountered and lexical information (i.e. the name). Recent findings indicated that semantic and episodic information retrieval is more likely to be elicited following familiar face than voice recognition. The present study was designed in order to explore the potential role of stimulus distinctiveness as an underlying factor of the face advantage. Design: The design included two within-subject factors: the stimulus domain (faces or voices) and the stimulus distinctiveness (distinctive or typical). Methods: The proportions of episodic and semantic information recalled following the recognition of famous faces and voices was assessed, using an adapted version of the Remember/Know paradigm. Results: In line with earlier results, more semantic and episodic information was retrieved from faces than voices. Moreover, semantic information was better retrieved from distinctive than typical stimuli. Nonetheless, distinctiveness impacted less than domain on the recall of semantic information, since more semantic details were retrieved from typical faces than from distinctive voices. Conclusions: These results are discussed in the light of current models of person recognition. [less ▲]

The own-age bias in age estimation of voices

Poster (2012, May)

Recently, it has been evidenced that age estimation performance may be influenced by an own-age bias, i.e. we can estimate more accurately the age of one’s own-age people than the age of other age people ... [more ▼]

Recently, it has been evidenced that age estimation performance may be influenced by an own-age bias, i.e. we can estimate more accurately the age of one’s own-age people than the age of other age people (George & Hole, 1995). To the best of our knowledge, all the studies that investigated the own-age bias used faces as stimuli. However, there are situations in which the voice is the only information available in order to estimate a person’s age (Cerrato et al., 2000). In the present study, the occurrence of an own-age bias in age estimation from voices was assessed by using an experimental design in which the age of participants (young vs old people) and the age of face stimuli (young vs old people) are crossed. Although we did not observe a crossed interaction where each age group would have been more accurate for in-group estimation than for out-group estimation, present results revealed the occurrence of an own-age bias in age estimation in younger adults only. Indeed young participants made smaller absolute errors than older participants when estimating the age of young voices. However, there was no significant difference between age groups when the age of older voices was estimated. [less ▲]

Does delay release the verbal overshadowing effect in child and adult eyewitnesses?

in Perception (2012), 41(supplement), 194

The verbal overshadowing effect (VO) (eg, Schooler and Engstler-Schooler, 1990 Cognitive Psychology 22(1) 36–71) suggests that the fact of generating a verbal description of a previously seen face may ... [more ▼]

The verbal overshadowing effect (VO) (eg, Schooler and Engstler-Schooler, 1990 Cognitive Psychology 22(1) 36–71) suggests that the fact of generating a verbal description of a previously seen face may impair subsequent performance on a lineup identification task in adults. Previous research has examined whether descriptions also impaired children’s identification abilities but no evidence of VO was found (Memon and Rose, 2002 Psychology, Crime and Law 8(3), 229–242). However, the method might not have been appropriate to observe this effect as, for instance, a 24-hour delay between the description and the identification tasks (associated with a release of the VO effect in adults) was used. Hence, in this current experiment, groups of children (7–8, 10–11, 13–14 years old) and adults were presented with a short video and then assigned to a description or a no description condition before the identification task. Participants were also assigned either to a “no delay”, a “24-hour post encoding delay” or a “24-hour post description delay” condition to determine the influence of delay on the VO effect. Results indicated that, compared to the control condition, the description decreased correct identification performance in both children and adults and no release of VO was found with delay. [less ▲]

Do you sound or look as old as you are? A study of age estimation in young and older adults

in Perception (2012), 41(supplement), 117

Studies on age estimation usually indicated that people are fairly accurate at estimating the age of a person from her/his face or from her/his voice (with an absolute difference of five and ten years ... [more ▼]

Studies on age estimation usually indicated that people are fairly accurate at estimating the age of a person from her/his face or from her/his voice (with an absolute difference of five and ten years respectively) [e.g. Amilon et al., 2000, in: Speaker Classification II. Lectures Notes in Artificial Intelligence, C Müller, Berlin, Springer-Verlag]. However studies showed also that performance depends on the age of participants and the age of stimuli [Rhodes, 2009, Applied Cognitive Psychology, 23, 1-12; Braun, 1996, Forensic Linguistics, 3, 65-73]. The aim of the present study is to compare age estimation performance from faces and voices by using an experimental design in which the age of participants (young vs older), the age of stimuli (young vs older) and the stimulus domain (face vs voice) were crossed. Overall, the age of faces was more accurately estimated than the age of voices. Moreover performance of age estimation was better for young stimuli than for older stimuli. Finally, young participants made smaller absolute errors than older participants. However there is no difference between young and older participants when estimating the age of older stimuli. [less ▲]

Evidence of a verbal overshadowing effect in children

Poster (2011, August 01)

The report of verbal descriptions of a culprit by adult witnesses may impair their later identification ability, a phenomenon known as the “verbal overshadowing effect (VO)” (Schooler & Englster-Schooler ... [more ▼]

The report of verbal descriptions of a culprit by adult witnesses may impair their later identification ability, a phenomenon known as the “verbal overshadowing effect (VO)” (Schooler & Englster-Schooler, 1990). In spite of a large body of literature on the suggestibility of children testimony, only one study has examined whether descriptions also impaired children’s identification abilities in a single group of children (8-9 years old) and no evidence of VO was found (Memon & Rose, 2002). However, some procedural details were not controlled in this experiment and the absence of a control adult group did not allow determining whether the procedure used was able to induce a VO effect. Hence, 2 experiments were conducted on several groups of children (7-8, 10-11, 13-14 years old) and adults to determine the influence of development on the VO effect. Overall, a VO effect on face identification was found in both experiments. The quality and influence of descriptors across the ages were also examined. [less ▲]

Two distinct neuronal networks mediate the awareness of environment and of self

in Journal of Cognitive Neuroscience (2011), 23(3), 570-578

Evidence from functional neuroimaging studies on resting state suggests that there are two distinct anticorrelated cortical systems that mediate conscious awareness: an "extrinsic" system that encompasses ... [more ▼]

Evidence from functional neuroimaging studies on resting state suggests that there are two distinct anticorrelated cortical systems that mediate conscious awareness: an "extrinsic" system that encompasses lateral fronto-parietal areas and has been linked with processes of external input (external awareness), and an "intrinsic" system which encompasses mainly medial brain areas and has been associated with internal processes (internal awareness). The aim of our study was to explore the neural correlates of resting state by providing behavioral and neuroimaging data from healthy volunteers. With no a priori assumptions, we first determined behaviorally the relationship between external and internal awareness in 31 subjects. We found a significant anticorrelation between external and internal awareness with a mean switching frequency of 0.05 Hz (range: 0.01-0.1 Hz). Interestingly, this frequency is similar to BOLD fMRI slow oscillations. We then evaluated 22 healthy volunteers in an fMRI paradigm looking for brain areas where BOLD activity correlated with "internal" and "external" scores. Activation of precuneus/posterior cingulate, anterior cingulate/mesiofrontal cortices, and parahippocampal areas ("intrinsic system") was linearly linked to intensity of internal awareness, whereas activation of lateral fronto-parietal cortices ("extrinsic system") was linearly associated with intensity of external awareness. [less ▲]

The neural correlates of visual self-recognition

in Consciousness and Cognition (2011), 20

This paper presents a review of studies that were aimed at determining which brain regions are recruited during visual self-recognition, with a particular focus on self-face recognition. A complex ... [more ▼]

This paper presents a review of studies that were aimed at determining which brain regions are recruited during visual self-recognition, with a particular focus on self-face recognition. A complex bilateral network, involving frontal, parietal and occipital areas, appears to be associated with self-face recognition, with a particularly high implication of the right hemisphere. Results indicate that it remains difficult to determine which specific cognitive operation is reflected by each recruited brain area, in part due to the variability of used control stimuli and experimental tasks. A synthesis of the interpretations provided by previous studies is presented. The relevance of using self-recognition as an indicator of self-awareness is discussed. We argue that a major aim of future research in the field should be to identify more clearly the cognitive operations induced by the perception of the self-face, and search for dissociations between neural correlates and cognitive components. [less ▲]

Near-Death Experiences and coma memories : real or imagined?

Poster (2010, July)