The use of virtual reality as a perspective-taking manipulation to improve self-awareness in Alzheimer's disease.

Lack of awareness of symptoms or having a condition referred to as anosognosia is a common feature of individuals with Alzheimer's Disease (AD). Previous literature on AD reported difficulties in evaluating self-abilities, often showing underestimation of limitations. There is increasing evidence that the perspective through which information is presented may moderate the performance appraisal and that anosognosia in AD might be a consequence of a deficit in assuming a third-person perspective. In this context, some studies showed that subjects may better recognize self-and other-difficulties when exposed to a third-person perspective. Considering the variety of approaches aiming to investigate the lack of awareness, there is still a scarcity of methods that provide great ecological validity and consider more than one facet of awareness, thus failing to offer more accurate evaluations of daily experiences. The present paper primarily addresses the theme of the multidimensional character of awareness of abilities in AD and the effect of perspective-taking on its trajectories. The focus turns to virtual reality as a promising tool for a greater evaluation of perspective-taking and self-awareness. Particularly, these systems offer the possibility to involve users in cognitive and sensorimotor tasks that simulate daily life conditions within immersive and realistic environments, and a great sense of embodiment. We propose that virtual reality might allow a great level of complexity, veracity, and safety that is needed for individuals with AD to behave according to their actual abilities and enable to explore the liaison between the subject's viewpoint, performance, and self-evaluation. In addition, we suggest promising clinical implications of virtual reality-based methods for individualized assessments, investigating specific impacts on subjects' life and possible improvements in their awareness.

Multidimensional assessment of social cognition using non-immersive virtual reality in dementia with Lewy bodies and Alzheimer's disease: an exploratory study.

INTRODUCTION: Few studies have focused on social cognition in dementia with Lewy bodies (DLB), even though some brain structures being well known as underlying social cognitive processes are directly impacted in this disease. Furthermore, social cognition processes have been mostly studied independently using evaluations with poor ecological validity. We aimed at studying the ability of a new naturalistic and multidimensional social cognition task to reveal impairments in DLB patients. We chose to compare the profile of these patients with that of Alzheimer's disease (AD) patients, for which social cognition is better preserved. METHOD: Fifteen patients (DLB: n = 7; AD: n = 8) and 28 healthy controls underwent the REALSoCog task. They encountered several social situations (e.g. control versus transgressions) in a non-immersive virtual city environment allowing the assessment of moral cognition, cognitive and affective theory of mind (ToM), emotional empathy and behavioral intentions. RESULTS: The main results showed (i) a lower ability to detect transgressions in DLB patients, particularly conventional ones, whereas moral cognition seemed better preserved in AD patients; (ii) a cognitive ToM impairment in both DLB and AD patients, while affective ToM is impaired only in DLB patients; (iii) a decreased emotional empathy specifically observed in DLB patients; (iv) more inappropriate behavioral intentions, mainly in DLB patients, but also in some AD patients. CONCLUSIONS: This study suggests the feasibility and potential interest of the REALSoCog task in revealing social cognition deficits, particularly for DLB patients by showing different social patterns as compared to AD patients. These results offer interesting clinical perspectives to develop more naturalistic tasks in such populations and for clinical differential diagnosis. Limitations and future perspectives are discussed.

Autonomic and cognitive control in memory: Investigating the psychophysiological link using heart rate variability biofeedback.

Vagally mediated heart rate variability (vmHRV) at resting state has been associated to cognitive functions dependent on cognitive control, such as memory. However, little is known about the phasic interaction between cognitive and autonomic control. In a pre-registered within-between-subject designed experiment, the potential of vmHRV biofeedback to simultaneously stimulate vmHRV during memory processing and cognitive control over long-term memory was tested, along with investigating psychophysiological association. 71 young healthy adults completed (twice) a false memory task in virtual reality. Immediately before memory encoding and retrieval, participants practiced either vmHRV biofeedback or a control breathing exercise. Cognitive control over long-term memory was assessed as the confidence toward false memories and the capability to discriminate them from true memories. Resting-state vmHRV before each test and phasic vmHRV during memory encoding and retrieval were measured as the root mean square differences (RMSSD) in the heart period. vmHRV biofeedback had neither an immediate effect on measures of cognitive control over long-term memory nor on phasic RMSSD. Moreover, neither resting-state nor phasic vmHRV correlated to the cognitive scores. Consequently, the utility of HRV biofeedback as a psychophysiological stimulation tool and a link between vmHRV and cognitive control over long-term memory could not be verified. Exploratory analyses revealed that baseline shift in parasympathetic activity confounded the psychophysiological association. Future directions are provided that could shed light on the relationship between cognition and vmHRV.

The formation of episodic autobiographical memory is predicted by mental imagery, self-reference, and anticipated details.

Introduction: Despite the ecological nature of episodic memory (EM) and the importance of consolidation in its functioning, studies tackling both subjects are still scarce. Therefore, the present study aims at establishing predictions of the future of newly encoded information in EM in an ecological paradigm. Methods: Participants recorded two personal events per day with a SenseCam portable camera, for 10 days, and characterized the events with different subjective scales (emotional valence and intensity, self-concept and self-relevance, perspective and anticipated details at a month, mental images…). They then performed a surprise free recall at 5 days and 1 month after encoding. Machine learning algorithms were used to predict the future of events (episodic or forgotten) in memory at 1 month. Results: The best algorithm showed an accuracy of 78%, suggesting that such a prediction is reliably possible. Variables that best differentiated between episodic and forgotten memories at 1 month were mental imagery, self-reference, and prospection (anticipated details) at encoding and the first free recall. Discussion: These results may establish the basis for the development of episodic autobiographical memory during daily experiences.

Reduction of alcohol use and increase in psychological flexibility after a naturalistic psychedelic experience: a retrospective survey.

INTRODUCTION: Alcohol use can be significantly associated with negative social, professional, and health outcomes. Even more so, alcohol use disorder (AUD) is a critical public health issue and major avoidable risk factor. This study aimed to examine the effect of a naturalistic psychedelic experience on alcohol use and related measures. METHODS: A retrospective online survey was conducted on 160 individuals who reported a psychedelic experience and a concomitant drinking habit but did not necessarily have an AUD. Demographic data, characteristics of the psychedelic experience, and changes in alcohol consumption and psychological flexibility were surveyed. Results: The mean number of drinking days per week and AUDIT scores significantly decreased after the psychedelic experience (P < .001). Subjects who quit or reduced drinking had a more severe AUD (P < .01) and lower psychological flexibility (P = .003) before the psychedelic session. Alcohol use reduction was significantly associated with the intensity of the mystical experience (P = .03). Psychological flexibility increased more in participants who reduced their alcohol use (P < .001), and the change in psychological flexibility was one of the predictors of alcohol use improvement (P = .003). Conclusion: Our findings suggest that a naturalistic psychedelic experience could be associated with a reduction in alcohol use and dependency. Such positive health outcomes can be associated with the intensity of the mystical experience as well as an increase in psychological flexibility.

Neurophysiological explorations across the spectrum of psychosis, autism, and depression, during wakefulness and sleep: protocol of a prospective case-control transdiagnostic multimodal study (DEMETER).

BACKGROUND: Quantitative electroencephalography (EEG) analysis offers the opportunity to study high-level cognitive processes across psychiatric disorders. In particular, EEG microstates translate the temporal dynamics of neuronal networks throughout the brain. Their alteration may reflect transdiagnostic anomalies in neurophysiological functions that are impaired in mood, psychosis, and autism spectrum disorders, such as sensorimotor integration, speech, sleep, and sense of self. The main questions this study aims to answer are as follows: 1) Are EEG microstate anomalies associated with clinical and functional prognosis, both in resting conditions and during sleep, across psychiatric disorders? 2) Are EEG microstate anomalies associated with differences in sensorimotor integration, speech, sense of self, and sleep? 3) Can the dynamic of EEG microstates be modulated by a non-drug intervention such as light hypnosis? METHODS: This prospective cohort will include a population of adolescents and young adults, aged 15 to 30 years old, with ultra-high-risk of psychosis (UHR), first-episode psychosis (FEP), schizophrenia (SCZ), autism spectrum disorder (ASD), and major depressive disorder (MDD), as well as healthy controls (CTRL) (N = 21 × 6), who will be assessed at baseline and after one year of follow-up. Participants will undergo deep phenotyping based on psychopathology, neuropsychological assessments, 64-channel EEG recordings, and biological sampling at the two timepoints. At baseline, the EEG recording will also be coupled to a sensorimotor task and a recording of the characteristics of their speech (prosody and turn-taking), a one-night polysomnography, a self-reference effect task in virtual reality (only in UHR, FEP, and CTRL). An interventional ancillary study will involve only healthy controls, in order to assess whether light hypnosis can modify the EEG microstate architecture in a direction opposite to what is seen in disease. DISCUSSION: This transdiagnostic longitudinal case-control study will provide a multimodal neurophysiological assessment of clinical dimensions (sensorimotor integration, speech, sleep, and sense of self) that are disrupted across mood, psychosis, and autism spectrum disorders. It will further test the relevance of EEG microstates as dimensional functional biomarkers. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT06045897.

Dynamic and/or multimodal assessments for social cognition in neuropsychology: results from a systematic literature review.

Objective: Despite the prevalence of socio-cognitive disturbances, and their important diagnostic/therapeutic implications, the assessment of these disturbances remains scarce. This systematic review aims to identify available social cognition tools for adult assessment that use multimodal and/or dynamic social cues, specifying their strengths and limitations (e.g. from a methodological, psychometric, ecological, and clinical perspective). Method: An electronic search was conducted in Pubmed, PsychINFO, Embase and Scopus databases for articles published up to the 3th of January 2023 and the first 200 Google Scholar results on the same date. The PRISMA methodology was applied, 3884 studies were screened based on title and abstract and 329 full texts were screened. Articles using pseudo-dynamic methodologies (e.g. morphing), reported only subjective or self-reported measures, or investigated only physiological or brain activity responses were excluded. Results: In total, 149 works were included in this review, representing 65 assessment tools (i.e. 48% studying emotion recognition (n = 31), 32% Theory of Mind (n = 21), 5% empathy (n = 3), 1.5% moral cognition/social reasoning (n = 1), and 14% being multimodal (n = 9)). For each study, the tool's main characteristics, psychometric properties, ecological validity indicators and available norms are reported. The tools are presented according to social-cognitive process assessed and communication channels used. Conclusions: This study highlights the lack of validated and standardized tools. A few tools appear to partially meet some clinical needs. The development of methodologies using a first-person paradigm and taking into account the multidimensional nature of social cognition seems a relevant research endeavour for greater ecological validity.

The role of bodily self-consciousness in episodic memory of naturalistic events: an immersive virtual reality study.

Recent studies suggest that the human body plays a critical role in episodic memory. Still, the precise relationship between bodily self-consciousness (BSC) and memory formation of specific events, especially in real-life contexts, remains a topic of ongoing research. The present study investigated the relationship between BSC and episodic memory (EM) using immersive virtual reality (VR) technology. Participants were immersed in an urban environment with naturalistic events, while their visuomotor feedback was manipulated in three within-subjects conditions: Synchronous, Asynchronous, and No-body. Our results show that asynchronous visuomotor feedback and not seeing one's body, compared to synchronous feedback, decrease the sense of self-identification, self-location and agency, and sense of presence. Moreover, navigating in the Asynchronous condition had a detrimental impact on incidental event memory, perceptual details, contextual association, subjective sense of remembering, and memory consolidation. In contrast, participants in the No-Body condition were only impaired in egocentric spatial memory and the sense of remembering at ten-day delay. We discuss these findings in relation to the role of bodily self-representation in space during event memory encoding. This study sheds light on the complex interplay between BSC, sense of presence, and episodic memory processes, and strengthens the potential of embodiment and VR technology in studying and enhancing human cognition.

Validation of a French Version of the Mystical Experience Questionnaire with Retrospective Reports of the Most Significant Psychedelic Experience among French Users.

Mystical experiences triggered by psychedelic drugs predict symptom reduction in various psychiatric disorders, and increased well-being in healthy individuals. This work aimed at validating a French version of a tool used to measure mystical experiences: the Revised Mystical Experience Questionnaire-30 items (MEQ30). Construct validity, internal consistencies, concurrent, discriminant, and predictive validities of the French MEQ30 were examined using data about the most significant psychedelic experience of 320 French individuals. Results showed that the original four-factor (i.e., mystical, positive mood, transcendence, and ineffability) structure fit the data best, with good to excellent statistical indices. Total French MEQ30 score was strongly associated with subjective ratings of the mystical (i.e., mystical, spiritual, or religious, and personally significant) and drug intensity-related qualities of the experience, but not with non-mystical (i.e., fun, inebriating, and easy) qualities. Moreover, French MEQ30 score was a significant predictor of subjective positive changes in psychological well-being, relations with self and others, feeling of proximity or connection with nature, and creativity, whereas drug intensity-related and non-mystical qualities of the experience were not, or were only weakly associated with such changes. This French version of the MEQ30 seems to be an appropriate tool for measuring mystical experiences among French speaking individuals.

Respiratory sinus arrhythmia during biofeedback is linked to persistent improvements in attention, short-term memory, and positive self-referential episodic memory.

Background: Heart rate variability (HRV) biofeedback, an intervention based on the voluntary self-regulation of autonomic parameters, has been shown to affect prefrontal brain functioning and improve executive functions. The interest in using HRV biofeedback as cognitive training is typically ascribed to parasympathetic activation and optimized physiological functioning deriving from increased cardiac vagal control. However, the persistence of cognitive effects is poorly studied and their association with biofeedback-evoked autonomic changes has not yet been explored. In addition, no study has so far investigated the influence of HRV biofeedback in adults on long-term episodic memory, which is particularly concerned with self-referential encoding processing. Methods: In the present study, a novel training system was developed integrating HRV and respiratory biofeedback into an immersive virtual reality environment to enhance training efficacy. Twenty-two young healthy adults were subjected to a blinded randomized placebo-controlled experiment, including six self-regulation training sessions, to evaluate the effect of biofeedback on autonomic and cognitive changes. Cardiac vagal control was assessed before, during, and 5 min after each training session. Executive functions, episodic memory, and the self-referential encoding effect were evaluated 1 week before and after the training program using a set of validated tasks. Results: Linear mixed-effects models showed that HRV biofeedback greatly stimulated respiratory sinus arrhythmia during and after training. Moreover, it improved the attentional capabilities required for the identification and discrimination of stimuli ( η p 2 = 0.17), auditory short-term memory ( η p 2 = 0.23), and self-referential episodic memory recollection of positive stimuli ( η p 2 = 0.23). Episodic memory outcomes indicated that HRV biofeedback reinforced positive self-reference encoding processing. Cognitive changes were strongly dependent on the level of respiratory sinus arrhythmia evoked during self-regulation training. Conclusion: The present study provides evidence that biofeedback moderates respiration-related cardiac vagal control, which in turn mediates improvements in several cognitive processes crucial for everyday functioning including episodic memory, that are maintained beyond the training period. The results highlight the interest in HRV biofeedback as an innovative research tool and medication-free therapeutic approach to affect autonomic and neurocognitive functioning. Finally, a neurocognitive model of biofeedback-supported autonomic self-regulation as a scaffolding for episodic memory is proposed.

Where Is My Mind ? The Link between Mind Wandering and Prospective Memory.

Mind wandering (MW) is a common feature of the human experience occurring when our attention shifts from the task at hand to inner thoughts. MW seems to be often future-oriented and could be used to help people to carry out their planned actions (Prospective Memory PM). Here, we tested the link between MW and the ability to perform PM intentions. We assessed MW and PM over 15 days using experience-sampling probes via mobile phone (226 participants) associated with a naturalistic PM task. We confirmed that MW occupies a significant proportion of our mental activity (40%). This time seems to be mainly used to project ourselves into the future (64%), whether to anticipate and imagine the long term (20%) or to plan daily obligations (44%). Intriguingly, only past-oriented thoughts (9%) predict the PM performance. We discuss the possible functional role played by MW in maintaining intentions in mind.

Is a wandering mind a sign of aging? / Avoir l'esprit vagabond : un signe de vieillissement ?

Mind wandering occupies an essential part of our awakened life and concerns all spontaneous thoughts unrelated to an ongoing activity. Laboratory research has studied this mental state during the execution of specific tasks measuring the conditions of emergence, the frequency and content of spontaneous thoughts and the consequences, usually harmful, on the performances tested. This mini review aims to define the phenomenon, expose the prejudices on performance and the assets of the wandering mind, and present the literature on the effects of cognitive aging on the incidence and characteristics of mind wandering. Various studies have shown a reduction in task-unrelated thoughts in the elderly, combined with an increase in task-related interfering thoughts. Some explanations are proposed, such as reducing cognitive resources or increasing motivation in the context of normal aging. The content of mind wandering seems crucial to understanding how this phenomenon evolves in aging. Hence, in future research, an assessment of the characteristics of the thoughts (emotion, temporality, association with stimuli, etc.) will deepen our knowledge of the link between mind wandering and aging.

Le vagabondage de l'esprit occupe une part importante de notre vie éveillée et concerne toutes les pensées spontanées qui ne sont pas liées à une activité en cours. Les recherches effectuées en laboratoire ont étudié cet état mental lors de la réalisation de tâches précises mesurant les conditions d'émergence, la fréquence et le contenu des pensées spontanées et les conséquences, généralement délétères, sur les performances testées. L'objectif de cette mini-revue est tout d'abord de définir le phénomène et ses conséquences néfastes sur les performances, d'examiner néanmoins les atouts de l'esprit vagabond, et enfin de présenter la littérature sur les effets du vieillissement cognitif dans l'incidence et les caractéristiques du vagabondage de l'esprit. Différentes études mettent en évidence, chez les sujets âgés, une réduction des pensées non liées à la tâche associée à une augmentation des pensées interférentes liées à la tâche. Plusieurs pistes explicatives sont proposées, comme la réduction des ressources cognitives ou l'augmentation de la motivation dans le cadre du vieillissement normal. La nature de contenu du vagabondage de l'esprit semble cruciale pour comprendre la manière dont ce phénomène évolue dans le cadre du vieillissement. Ainsi, dans l'avenir, une évaluation des caractéristiques des pensées (émotion, temporalité, lien avec les stimuli, etc.) permettra d'approfondir notre connaissance du lien entre vagabondage de l'esprit et vieillissement.

Using a Computer-Based Virtual Environment to Assess Social Cognition in Aging: An Exploratory Study of the REALSoCog Task.

Although previous studies have suggested that some component processes of social cognition decline in normal aging, several methodological limitations can be pointed out. Traditional sociocognitive tasks assess processes separately and lack ecological validity. In the present study, the main aim was to propose an integrative social cognition assessment in normal aging using an original computer-based task developed in non-immersive virtual reality. Forty-five young adults (YA) and 50 older adults (OA) were asked to navigate in a simulated city environment and to judge several situations that they encountered. These situations investigated social norms by displaying control or (conventional/moral) transgressions. Following each situation, the participants were asked several questions in order to assess their ability to make moral judgments, affective and cognitive theory of mind, emotional reactivity and empathy, and the propensity to act in a socially appropriate or inappropriate way. The main results showed (i) a preserved ability to detect moral and conventional transgressions with advancing age; (ii) participants' preserved cognitive ToM abilities; (iii) an age-related decline in affective ToM, that disappeared when the victim was a senior; (iv) preserved emotional reactivity and emotional empathy in normal aging; (v) an increase in inappropriate behavioral intentions in normal aging. Offering more naturalistic conditions, this new task is an interesting integrative measure of sociocognitive functioning to better reflect social behavior in daily living.

Temporosylvian arachnoid cysts in children. Part 2: Postoperative neuropsychological and clinical improvement.

OBJECTIVE: The authors' objective was to study clinical, imaging, and neuropsychological changes in children who underwent surgery for a temporal arachnoid cyst (TAC). METHODS: Thirty-four children were prospectively assessed similarly at diagnosis and postoperatively (mean 14 months) with clinic visits, images, cognitive tests, and parental questionnaires on mood/behavior and executive functions. The scores were compared pre- and postoperatively for the entire cohort and individually. The scores of 25 children were also compared with a control group of 23 healthy age-matched children. Parents were administered an outcome questionnaire on average 4 years postoperatively. RESULTS: The 34 children selected for surgery had signs of raised intracranial pressure (74%) and/or selective neuropsychological disorders presumably linked to cyst location (learning difficulties in 65%, cognitive difficulties in 56%, and mood/behavior difficulties in 47%). The majority of patients had a convex cyst (85%) and underwent microsurgical fenestration (85%). The TAC volume decreased ≥ 50% for 59% of children. On the Wechsler Intelligence Scale, the entire cohort significantly improved on Full Scale IQ and verbal and perceptual nonverbal indexes. Individually, nearly half of the children (47%) highly increased their scores (≥ 15 points) on at least one IQ index and 26% on at least two indexes. Language, working memory, episodic memory, and executive functions were also significantly improved. Improvements were more pronounced in patients with a preoperative heterogeneous profile with isolated lower scores and a left-sided cyst. Parental questionnaires showed reduction in anxiety, aggressiveness, social problems, and daily life executive disorders. Preschool-aged children improved significantly in language and verbal IQ, as did middle/high school-aged children in many domains. Individual analyses revealed improvement in 76% of cases. Cognitive scores were lower for patients preoperatively than for controls and were no longer significantly different postoperatively in verbal fluency, visual memory, and working memory. Four years later, 97% of parents described an improvement in their child, correlated with cognitive improvements. CONCLUSIONS: Among children with a TAC, some have no clinical signs or neuropsychological difficulties, and others may show signs of raised intracranial pressure and/or specific neuropsychological disorders that impact daily life and require significant and long-lasting rehabilitation. In these cases, consideration may be given to surgical decompression. It is interesting to note that 76% of this surgically treated cohort improved regardless of the child's age, particularly in patients with selective disorders and an impact on daily life. However, a larger number of children will need to be investigated before the true benefit of such treatment can be known.

Temporosylvian arachnoid cysts in children. Part 1: Cognitive profile of children with a temporal cyst and impact of the cyst in daily life. A prospective study in 100 consecutive children.

OBJECTIVE: The aim of this study was to determine the cognitive profile of children with a temporal arachnoid cyst (TAC) and its impact on daily life. METHODS: The authors prospectively analyzed the cognitive and psychological profiles of 100 consecutive children relative to age and cyst characteristics (side, cyst size, and cyst shape: convex or nonconvex) and their outcome 4 years later. RESULTS: Mean IQs were normal but with high heterogeneity on Full Scale IQ (FSIQ; range 59-150); 29% of children had at least one Wechsler index below the norm, in particular, Processing Speed and Working Memory Indexes. Impairments were observed in language for 31% of children, as well as in verbal memory (28%), visual memory (23%), executive function (21%), and visual attention (24%). Half of the children (50%) needed rehabilitation for learning difficulties, and 26% had academic difficulties. The parental questionnaire BRIEF (Behavior Rating Inventory of Executive Function) revealed significant executive dysfunctions in daily life for 22% of the children. One-third of the patients (34%) required psychotherapy for anxiety or social disorders, with higher rates in patients with a right-sided cyst and older children. Cyst size had very little neuropsychological impact. Convex cysts were significantly associated with worse performance than nonconvex cysts on all Wechsler indexes and FSIQ, and in language, verbal memory, attention, and visuospatial skills. Children with a convex cyst had significantly more executive and behavior difficulties in daily life and more psychotherapy than other children. The effect of cyst shape was independent of Galassi type and cyst side. Children with a ruptured cyst or an incidentally discovered cyst usually had a good cognitive level. Four years later, children without initial disorders remained stable, whereas those with difficulties who did not undergo surgery needed more rehabilitation and school adaptations. CONCLUSIONS: This large cohort study revealed a varied profile of children with a TAC: at initial assessment, 50% had neuropsychological difficulties and needed rehabilitation and/or psychotherapy for learning or behavior difficulties, and 50% had no difficulties, which may explain the debate about this pathology. Patients with neuropsychological difficulties had a heterogeneous profile with normal intelligence but selective cognitive and/or behavior disorders that may have a long-term impact on their quality of life, particularly those with a right-sided cyst. A neuropsychological evaluation is not always necessary for a cyst discovered incidentally, but early evaluation is essential in patients with academic, learning, or psychological disorders. When assessment shows selective disorders presumably linked to cyst location, surgery may be considered, particularly for convex cysts, as this study revealed more effects in association with cyst shape than with cyst size and significantly poorer performance with a convex cyst.

"Run to the hills": Specific contributions of anticipated energy expenditure during active spatial learning.

Grounded views of cognition consider that space perception is shaped by the body and its potential for action. These views are substantiated by observations such as the distance-on-hill effect, described as the overestimation of visually perceived uphill distances. An interpretation of this phenomenon is that slanted distances are overestimated because of the integration of energy expenditure cues. The visual perceptual processes involved are, however, usually tackled through explicit estimation tasks in passive situations. The goal of this study was to consider instead more ecological active spatial processing. Using immersive virtual reality and an omnidirectional treadmill, we investigated the effect of anticipated implicit physical locomotion cost by comparing spatial learning for uphill and downhill routes, while maintaining actual physical cost and walking speed constant. In the first experiment, participants learnt city layouts by exploring uphill or downhill routes. They were then tested using a landmark positioning task on a map. In the second experiment, the same protocol was used with participants who wore loaded ankle weights. The results from the first experiment showed that walking uphill routes led to a global underestimation of distances compared with downhill routes. This inverted distance-of-hill effect was not observed in the second experiment, where an additional effort was applied. These results suggest that the underestimation of distances observed in Experiment 1 emerged from recalibration processes whose function was to solve the transgression of proprioceptive predictions linked with uphill energy expenditure. The results are discussed in relation to constructivist approaches on spatial representations and predictive coding theories.

How rich are false memories in a naturalistic context in healthy aging?

The recall of factual and contextual information is a core characteristic of episodic memory sensitive to aging effects. The innovative aim of the present study was to assess in a naturalistic context the quantity and quality of correct and false free recalls among younger and older adults considering feature binding (What-Where-When-Details) and recollection (Remembering vs. Knowing). Thanks to virtual reality, we designed a multimodal environment simulating a lively town in which we implemented a variant of a DRM task rich in sets of semantically related items (e.g., fruits on a market stall). We asked 30 young and 30 older participants to navigate in the virtual environment, paying attention to the items, and then recall as many items and as much contextual information as possible and indicate the presence of recollection. As expected, older adults produced fewer correct recall but more intrusions than younger adults, and their correct recall was more deficient in binding and recollection. In both age groups, false recall was associated with the correct context inferred from a related set of items. However, the intrusions produced by older adults were highly recollected compared to those of the younger adults, and they were associated with false item-related contextual information.

Mindfulness and false memories: state and dispositional mindfulness does not increase false memories for naturalistic scenes presented in a virtual environment.

Mindfulness attracted increased research interests in the last decade, reporting an overall beneficial effect of this practice on cognitive performances. Nevertheless, recently a possible detrimental impact of mindfulness has been underlined. While the effect of mindfulness on memory remains under-explored, recent studies have observed an increased false-memory susceptibility after mindfulness practice. A possible explanatory mechanism has been suggested, related to the nature of the studied material. For semantically related information, mindfulness would increase false memories; however, the addition of rich perceptual information could prevent this detrimental effect. The present study aimed to verify this hypothesis by testing the impact of state mindfulness induced by a short meditation session, and dispositional mindfulness on the production of false memory for pictorial material presented in a complex virtual environment. We employed a virtual reality version of the Deese-Roediger-McDermott paradigm (DRM), a classical protocol to induce false memories. Contrary to previous studies, we did not observe any effect of mindfulness on false or correct memories (free recall and recognition) after a short mindfulness practice session compared to a control condition. Nonetheless, we found a beneficial effect of mindfulness practice on memory sensitivity. Additionally, we reported a positive and negative effect of dispositional mindfulness on memory outcomes. While the Non-Reactivity facet was associated with overall better memory performances, we observed an association between the Acting with Awareness facet and an increased recollection of lures. We discuss these findings in line with a recent proposal on the link between mindfulness and episodic memory.

Bored, distracted, and forgetful: The impact of mind wandering and boredom on memory encoding.

Mind wandering, defined as focusing attention towards task-unrelated thoughts, is a common mental state known to impair memory encoding. This phenomenon is closely linked to boredom. Very few studies, however, have tested the potential impact of boredom on memory encoding. Thus, the present study aimed at manipulating mind wandering and boredom during an incidental memory encoding task, to test their differential impact on memory encoding. Thirty-two participants performed a variant of the n-back task in which they had to indicate if the current on-screen object was the same as the previous one (1-back; low working memory load) or the one presented three trials before (3-back; high working memory load). Moreover, thought probes assessing either mind wandering or boredom were randomly presented. Afterwards, a surprise recognition task was delivered. Results showed that mind wandering and boredom were highly correlated, and both decreased in the high working memory load condition, while memory performance increased. Although both boredom and mind wandering predicted memory performance taken separately, we found that mind wandering was the only reliable predictor of memory performance when controlling for boredom and working memory load. Model comparisons also revealed that a model with boredom only was outperformed by a model with mind wandering only and a model with both mind wandering and boredom, suggesting that the predictive contribution of boredom in the complete model is minimal. The present results confirm the high correlation between mind wandering and boredom and suggest that the hindering effect of boredom on memory is subordinate to the effect of mind wandering.