Alterations in resting-state functional connectivity associated to the age-related decline in time-based prospective memory.

Time-based prospective memory (TBPM) is defined as the ability to remember to perform intended actions at a specific time in the future. TBPM is impaired in aging, and this decline has been associated with white-matter alterations within the superior fronto-occipital fasciculus. In the present study, we used resting-state functional magnetic resonance imaging from 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 6.1 years) participants to investigate how age-related alterations in resting-state functional connectivity are related to TBPM performance, and whether these alterations are associated with the white-matter disruptions we have previously observed with diffusion tensor imaging. Whole-brain analyses revealed lower resting-state functional connectivity in older participants compared with younger ones, which in turn correlated with TBPM performance. These correlations were mainly located in the salience network and the parietal part of the frontoparietal network. Our findings suggest that resting-state functional connectivity alterations contribute to the age-related decline in TBPM.

Sleep-dependent memory consolidation in breast cancer: Use of a virtual reality prospective memory task.

Background: Previous studies have revealed both sleep alterations and prospective memory (PM) impairments in breast cancer (BC) patients. PM refers to memory of intended actions and is crucial for daily living tasks and treatment compliance. As sleep is known to favor memory consolidation, one may expect that changes in sleep quality related to BC would have an impact on PM performance. This study aimed at assessing sleep-dependent consolidation of intentions using an ecological, virtual reality-based PM task in BC patients not treated with chemotherapy. Materials and methods: Thirty-seven early stages BC patients and 21 healthy controls (HC) participated in this study. PM was assessed using a virtual reality task, during which participants learnt a list of intentions and recalled them after a retention interval filled with a day awake or a night of sleep monitored by polysomnography. Sleep spindles and slow waves, brain oscillations involved in sleep-dependent memory consolidation, were quantified automatically using the Aseega software (Physip). Subjective sleep disturbances and markers of quality of life (psychological distress, fatigue, and well-being) were assessed by questionnaires. Results: Greater PM performance was observed after sleep than after an equivalent period of daytime wakefulness for both groups (HC and BC). PM performance after sleep did not differ significantly between groups. Yet, BC patients reported greater sleep disturbances than HC which were related with poorer intentions retrieval, greater psychological distress, fatigue and poorer well-being. The frequency of spindles was higher and the amplitude of slow waves lower in BC patients compared to HC. However, no significant association was observed between polysomnography parameters and PM scores in the whole sample of participants. Conclusion: Although subtle changes in brain oscillations involved in sleep-dependent memory consolidation were observed, these changes did not significantly impair overnight PM consolidation in BC patients. Nevertheless, poorer PM performance was associated with greater sleep complaints which in turn were related to poorer quality of life. Overall, these data suggest that sleep-dependent PM consolidation mechanisms are not altered in early stages BC patients not treated with chemotherapy. Further investigations are needed to understand the association between markers of quality of life and sleep-dependent memory consolidation.

Functional connectivity of the medial prefrontal cortex related to mindreading abilities.

The medial prefrontal cortex is a key region of mindreading belonging to the mentalizing system, a set of brain areas underlying mental state inference based on reasoning on social concepts. The aim of this study was to characterize the functional connectivity between regions involved in mindreading and to highlight the processes it underpins, focusing on the dorsal and ventral parts of the medial prefrontal cortex. We analyzed resting-state functional magnetic resonance imaging of 56 healthy volunteers, to study the relationship between mindreading abilities and functional connectivity of the medial prefrontal cortex. Cognitive mindreading performances were correlated with connectivity between the medial prefrontal cortex and frontal regions involved in the regulation of the salience of one's own mental contents, with a distinction between the dorsal part connected to regions subtending inhibition processes and the ventral part to emotional regions. Affective mindreading performances were negatively correlated with negative connectivity of the ventro- and dorsomedial prefrontal cortex with sensorimotor regions belonging to the mirror neuron system subtending the simulation of mental states. These findings suggested a role of the medial prefrontal cortex to decrease the salience of one's own mental content and in the antisynchronous interaction between the mentalizing and mirror neurons systems.

Longitudinal grey matter and metabolic contributions to cognitive changes in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is characterized by rapidly evolving cognitive and brain impairments. While previous work revealed structural and functional alterations associated with cognitive decline in patients suffering from amyotrophic lateral sclerosis, the relationships between anatomo-functional changes and both disease's progression and the evolution of cognitive performance remain largely unexplored. Here, we took advantage of repeated multi-modal acquisitions in patients with amyotrophic lateral sclerosis over 1 year to assess the longitudinal sequence of grey matter atrophy, glucose metabolism and cognitive changes. Results revealed metabolic and structural changes over frontal, thalamic and temporal regions. Both cortical hypermetabolism and hypometabolism (right temporal gyrus and right angular gyrus, respectively) were associated with cognitive performance and thalamic hypometabolism during the follow-up testing session. Furthermore, the inferior frontal gyrus atrophy mediated the relation between early hypometabolism in this region and the subsequent decline of the theory of mind abilities. Marked volume loss was associated with larger hypometabolism and impaired cognitive performance. To our knowledge, this is the first study to longitudinally examine both grey matter volume and metabolic alteration patterns in patients with amyotrophic lateral sclerosis, over a mean follow-up time of 1 year. We identify how changes of the inferior frontal gyrus critically underly later cognitive performance, shedding new light on its high prognostic significance for amyotrophic lateral sclerosis-related changes. These results have important implications for our understanding of structural and functional changes associated with amyotrophic lateral sclerosis and how they underly cognitive impairments.

Social cognition in neuropsychology: A nationwide survey revealing current representations and practices.

As a key domain of cognition, social cognition abilities are altered in a wide range of clinical groups. Accordingly, many clinical tests and theories of social cognition have been developed these last decades. Contrasting this abundant development from a research perspective, recent evidence suggests that social cognition remains rarely addressed from a clinial perspective. The aim of the present research was to characterize the current practices, representations, and needs linked to social cognition from the perspective of professional neuropsychologists and graduate students. A nationwide survey allowed us to determine the classical field conception of social cognition and its associated symptoms or notions. It also allowed us to quantify practice activities and the use of the different clinical tools available. This study revealed that neuropsychologists lack confidence regarding social cognition assessment and its rehabilitation, and that students are in demand for more knowledge and training. Suggestions of change in practices and dissemination of knowledge are discussed. Considering the importance of social cognition, an extension of initial and continuous training alongside an enrichment of interactions between researchers and clinicians were key recommendations to formulate, as well as the need for a consensual lexicon of current concepts.

Self-referential processes and resting-state connectivity in breast cancer patients before and 1 year after chemotherapy.

Modifications in the processing of information relevant to oneself have been reported in breast cancer (BC) patients. Here, we characterize the longitudinal changes to self-representations in BC patients and how they are related to intrinsic functional brain connectivity. We tested 16 BC patients before (T1) and 1 year after the end of chemotherapy (T2) along with 24 healthy control participants (HC) at similar time points. Participants underwent resting-state fMRI and completed the Questionnaire of Self-Representation (QSR), which evaluates self-assertion and self-esteem. Resting-state functional connectivity (RSFC) was calculated for regions implicated in self-referential processes (dorsomedial prefrontal cortex [dmPFC], posterior cingulate cortex [PCC], and dorsal anterior cingulate cortex [dACC]) and correlated with QSR scores. QSR scores were on average larger in patients compared with HC and did not vary over time. RSFC between the dACC and regions supporting body awareness (precentral/postcentral and supramarginal gyri, superior parietal lobule) decreased more between T1 and T2 in BC patients than in HC. BC patients had lower RSFC than HC between the dmPFC and the PCC, and regions supporting mental imagery (precuneus, lingual gyrus), at each time point, and a greater decrease from T1 and T2. QSR scores negatively correlated with RSFC. Patients described themselves as having greater self-awareness and positive self-image, reflecting a fighting spirit. In parallel, patients presented a decrease in cortical activity related to body awareness and mental imagery of self-representations over time that may be related to the positive self-image patients have and could reflect a temporary adaptive strategy.

Are Sleep Complaints Related to Cognitive Functioning in Non-Central Nervous System Cancer? A Systematic Review.

Patients with non-central nervous system (CNS) cancer frequently report cognitive complaints, that are recurrent and affect their quality of life. In order to improve supportive care of these cognitive difficulties, it is important to identify associated factors. Sleep disturbance is a good candidate to study, as patients with non-CNS cancer frequently report sleep disorders, and sleep plays a key role in cognitive functioning. The objective of the present systematic review was to summarize the results of studies evaluating the relationship between cognition and sleep in non-CNS cancer, and to highlight the need for further studies. PubMed [Medline] and Scopus databases were screened from April to November 2020 for studies published in English evaluating the association between cognition and sleep in adults with non-CNS cancer. The characteristics and risk of bias for each of the 30 included studies have been reported. Greater cognitive complaints in patients with non-CNS cancer were related to poorer self-reported sleep quality in almost all studies (n = 22/24). By contrast, around half of the studies reported a significant association between poorer neuropsychological performances and sleep complaints (n = 5/11). The studies were found to have several limitations, such as the lack of a control group, which would have shed the light on the period of occurrence of this association (e.g. after cancer diagnosis or after cancer treatments). Our review also identified factors that may influence the relationship between cognition and sleep. Recommendations are given for improving the methodology of future studies and extending the impact of their results.

Sex-specificities in anxiety and depressive symptoms across the lifespan and their links with multimodal neuroimaging.

BACKGROUND: Anxiety and depressive symptoms are associated with impaired well-being, higher risk of developing psychoaffective disorders and are risk factors for Alzheimer's disease (AD). To further understand their relevance and the mechanisms underlying their link with AD, our aims were to assess how anxiety and depressive symptoms changed with age and related to AD neuroimaging biomarkers across the adult lifespan, while also exploring sex specificities. METHODS: 210 cognitively normal participants aged 19-86 years (101 men, 109 women) completed assessments of anxiety and depressive symptoms with the STAI-A and MADRS respectively, and neuroimaging measurements including structural MRI, FDG-PET and amyloid-PET. 167 of those were followed-up over 1.5-3 years. Multiple regressions were performed to assess the links between anxiety or depressive symptoms versus age, global cognition or each imaging modality, both cross-sectionally and longitudinally; and general linear models we used to test the interactive effect of sex on these associations. RESULTS: Depressive symptoms decreased with age, while anxiety symptoms increased only among women. Higher anxiety symptoms were associated with lower grey matter (GM) volume and glucose metabolism, with an interaction of sex, this relationship being significant only in women. Longitudinally, only low baseline GM volume predicted an increase in anxiety symptoms with time. LIMITATIONS: Only 43% of participants reported depressive symptoms. Despite additional analyses, the low variability in the measure might have prevented us from detecting subtle changes. CONCLUSIONS: This study emphasizes the need to consider anxiety symptoms in assessments for dementia risk, particularly in women.

Longitudinal Study of Cognitive and Emotional Alterations in Amyotrophic Lateral Sclerosis: Clinical and Imaging Data.

Objectives: Extra-motor manifestations occur in 50% of patients with amyotrophic lateral sclerosis (ALS). These mainly concern cognition, emotional processing and behavior. Depression and anxiety are less frequent. Little is known about how these manifestations change as the disease progresses. Similarly, although cortical thinning has been well-documented at disease onset, there are scant data about cortical thinning over time and how this correlates with extra-motor manifestations. The present study therefore assessed cognitive, emotional and psychological state and cortical thinning in a group of patients with ALS at baseline and after a follow-up period. Methods: We assessed executive functions, facial emotion recognition, depressive and anxious symptoms, and cortical thinning in 43 patients with ALS at baseline, comparing them with 28 healthy controls, and 21 of them 9 months later. We looked for links among the extra-motor manifestations and correlations with cortical thickness. Results: At baseline, patients had poor executive function and recognition of complex emotions from the eyes, and more anxious and depressive symptoms than controls. At follow-up, only inhibition abilities had worsened. Cortical thinning was observed in bilateral pre-central regions and other parts of the cerebral cortex at baseline. Over time, it worsened in motor and extra-motor areas. Executive functions correlated with thinning in the middle and inferior frontal gyrus and orbitofrontal cortex. Conclusions: During follow-up, there was little deterioration in extra-motor manifestations and psychological state, despite continuing cortical thinning. Patients with affective Theory of Mind (ToM) changes seemed less depressed than the others. Impaired mental flexibility was subtended by prefrontal regions with cortical thinning.

Boosting Autobiographical Memory and the Sense of Identity of Alzheimer Patients Through Repeated Reminiscence Workshops?

Despite severe amnesia, some studies showed that Alzheimer Disease (AD) patients with moderate to severe dementia keep a consistent, but impoverished representation of themselves, showing preservation of the sense of identity even at severe stages of the illness. Some studies suggest that listening to music can facilitate the reminiscence of autobiographical memories and that stimulating autobiographical memory would be relevant to support the self of these patients. Consequently, we hypothesized that repeated participation to reminiscence workshops, using excerpts of familiar songs as prompts would participate to the enrichment of autobiographical memories, self-representation and sense of identity. We included a group of 20 AD patients with severe dementia residing in nursing homes. Their performances were compared to a control group of 20 matched (age, education, mood) healthy residents living in the same institutions. The experiment was conducted in three phases over a 2-week period. On phase 1, an individual assessment of sense of identity was proposed to each participant. On phase 2, participants joined musical reminiscence workshops (six sessions over 2 weeks for AD patients and 3 sessions over a week for controls). During the third phase (12 days after the first assessment), individual evaluation of autobiographical memory and a second assessment of sense of identity were proposed. Our results showed that, despite their massive amnesia syndrome, autobiographical memories of AD reached at the end of the 2 weeks the number and quality of those of matched controls. Moreover, we confirmed a continuity of self-representation in AD patients with a stable profile of the answers between the first and second individual assessments of sense of identity. However, the increase in number and episodic quality of autobiographical memories was not accompanied by an enrichment of the sense of identity. In a complementary study, new patients participated in the same paradigm, but using movie extracts as prompts, and showed very similar effects. We discuss all of these results with regard to the literature showing the significant impact of repetition on the reactivation of memory traces even in very amnestic AD patients at severe stages of the disease.

Brain Substrates of Time-Based Prospective Memory Decline in Aging: A Voxel-Based Morphometry and Diffusion Tensor Imaging Study.

Time-based prospective memory (TBPM) allows us to remember to perform intended actions at a specific time in the future. TBPM is sensitive to the effects of age, but the neural substrates of this decline are still poorly understood. The aim of the present study was thus to better characterize the brain substrates of the age-related decline in TBPM, focusing on macrostructural gray matter and microstructural white matter integrity. We administered a TBPM task to 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 5.9 years) participants, who also underwent volumetric magnetic resonance imaging and diffusion tensor imaging scans. Neuroimaging analyses revealed lower gray matter volumes in several brain areas in older participants, but these did not correlate with TBPM performance. By contrast, an age-related decline in fractional anisotropy in several white-matter tracts connecting frontal and occipital regions did correlate with TBPM performance, whereas there was no significant correlation in healthy young subjects. According to the literature, these tracts are connected to the anterior prefrontal cortex and the thalamus, 2 structures involved in TBPM. These results confirm the view that a disconnection process occurs in aging and contributes to cognitive decline.

When affect overlaps with concept: emotion recognition in semantic variant of primary progressive aphasia.

The most recent theories of emotions have postulated that their expression and recognition depend on acquired conceptual knowledge. In other words, the conceptual knowledge derived from prior experiences guide our ability to make sense of such emotions. However, clear evidence is still lacking to contradict more traditional theories, considering emotions as innate, distinct and universal physiological states. In addition, whether valence processing (i.e. recognition of the pleasant/unpleasant character of emotions) also relies on semantic knowledge is yet to be determined. To investigate the contribution of semantic knowledge to facial emotion recognition and valence processing, we conducted a behavioural and neuroimaging study in 20 controls and 16 patients with the semantic variant of primary progressive aphasia, a neurodegenerative disease that is prototypical of semantic memory impairment, and in which an emotion recognition deficit has already been described. We assessed participants' knowledge of emotion concepts and recognition of 10 basic (e.g. anger) or self-conscious (e.g. embarrassment) facial emotional expressions presented both statically (images) and dynamically (videos). All participants also underwent a brain MRI. Group comparisons revealed deficits in both emotion concept knowledge and emotion recognition in patients, independently of type of emotion and presentation. These measures were significantly correlated with each other in patients and with semantic fluency in patients and controls. Neuroimaging analyses showed that both emotion recognition and emotion conceptual knowledge were correlated with reduced grey matter density in similar areas within frontal ventral, temporal, insular and striatal regions, together with white fibre degeneration in tracts connecting frontal regions with each other as well as with temporal regions. We then performed a qualitative analysis of responses made during the facial emotion recognition task, by delineating valence errors (when one emotion was mistaken for another of a different valence), from other errors made during the emotion recognition test. We found that patients made more valence errors. The number of valence errors correlated with emotion conceptual knowledge as well as with reduced grey matter volume in brain regions already retrieved to correlate with this score. Specificity analyses allowed us to conclude that this cognitive relationship and anatomical overlap were not mediated by a general effect of disease severity. Our findings suggest that semantic knowledge guides the recognition of emotions and is also involved in valence processing. Our study supports a constructionist view of emotion recognition and valence processing, and could help to refine current theories on the interweaving of semantic knowledge and emotion processing.

New Long-Term Encoding in Severely Amnesic Alzheimer's Disease Patients Revealed Through Repeated Exposure to Artistic Items.

BACKGROUND: Encoding of new information is considered to be impossible in people with Alzheimer's disease (PWAD) at a moderate to severe stage. However, a few case studies reported new learning under special circumstances, especially with music. OBJECTIVE: This article aims at clarifying PWAD's learning capacities toward unknown material under more ecological settings, which is repeated exposure without encoding instruction. METHODS: Twenty-three PWAD (Age: m = 84.6(5.2), 5≤MMSE≤19) underwent presentations of unknown artistic pieces (targets) through 8 daily individual sessions. These sessions were followed by a test session, during which their knowledge of the targets was assessed through a verbal and behavioral scale (the sense of familiarity scale) against a series of unknown items (distractors). RESULTS: Through this design, we were able to objectify encoding of three types of targets (verses, paintings, and music) against distractors the day after exposure sessions, and 2 months after the last presentation (study 1). Music and paintings were eventually well-encoded by most participants, whereas poems encoding was poorer. When compared to distractors, target items were significantly better recognized. We then compared the recognition of target paintings against two types of painting distractors, either perceptually or semantically related (study 2). The targets were better recognized than all three painting distractors, even when they were very close to the targets. CONCLUSION: Despite massive anterograde amnesia, our results clearly showed that recognition-based learning without conscious memory of the encoding context is preserved in PWAD at a severe stage, revealed through an increasing sense of familiarity following repeated exposure. These findings could open new perspective both for researchers and clinicians and improve the way we understand and care for PWAD living in healthcare facilities.

Specific cognitive theory of mind and behavioral dysfunctions in early manifest Huntington disease: a case report.

Huntington's disease (HD) is a devastating illness, associated with progressive motor, behavioral and cognitive dysfunctions. However, some studies emphasized that social cognition impairment could occur prior to the onset of these other symptoms. Here, we report the case of a 47 years old patient with early manifest HD, whose complaint was mainly related to the behavioral sphere. He exhibited a significant impairment of Theory of Mind abilities as well as behavioral, and discrete motor symptoms without noticeable cognitive decline. This case study suggests that social cognition impairments and behavioral changes could be in some cases a feature of the disease and may represent a major disability, in early stages of manifest HD.

Influence of emotional complexity on the neural substrates of affective theory of mind.

Affective theory of mind (ToM) depends on both the decoding of emotional expressions and the reasoning on emotional mental states from social situations. While previous studies characterized the neural substrates underlying these processes, it remains unclear whether the nature of the emotional state inferred from others can influence the brain activation associated with affective ToM. In the present study, we focused on two types of emotions: basic emotions (BEs) (e.g., anger and surprise), which are innate and universal and self-conscious emotions (e.g., pride and embarrassment), which correspond to a special class of emotions involving the self and including a representation of one's relative reactions to internal and external standards. Specifically, we used an ecological functional MRI paradigm, on 21 healthy young subjects, to compare brain activations during the decoding of and the reasoning on others' self-conscious, basic and neutral mental states. Our results showed that compared to neutral states, the inference of self-conscious and basic emotional states from others elicited more activation in several core regions of affective ToM. Direct comparisons between emotional conditions revealed more activation for self-conscious than BEs in the right temporoparietal junction during the reasoning process and in left middle occipital regions during the decoding process. Further analyses using a localizer task showed that the extrastriate body area was more recruited for decoding others' self-conscious versus BEs, which emphasize the importance of body clues to properly infer these emotions. Using an original task allowing for an ecological assessment of the affective ToM, these results demonstrate that the complexity of the emotion inferred to others can influence the recruitment of ToM network. This study also validates the use of our task as an ecological tool to assess the affective ToM, constituting an avenue for the characterization of ToM impairments in neurological conditions.

Prospective Memory in Adolescents with Autism: A Preliminary Study of the Impact of Memory Load.

We evaluated event-based prospective memory (EBPM) in adolescents with Autism, varying the load of the to-be-performed intentions. We included measures of inhibition, working memory and binding. Results showed that increasing the retrospective memory load reduced performance in controls. In Autism, adolescents were impaired in the low load condition with normal performance for the ongoing task, with the reverse pattern in the high load condition. EBPM may be impacted in Autism due to difficulty to process ongoing and EBPM tasks simultaneously possibly because of restricted inhibitory control.

Ageing stereotypes and prodromal Alzheimer's disease (AGING): study protocol for an ongoing randomised clinical study.

INTRODUCTION: The number of older people diagnosed with amnestic mild cognitive impairment (aMCI), the prodromal state of Alzheimer's disease (AD), is increasing worldwide. However, some patients with aMCI never convert to the AD type of dementia, with some remaining stable and others reverting to normal. This overdiagnosis bias has been largely overlooked and gone unexplained. There is ample evidence in the laboratory that negative ageing stereotypes (eg, the culturally shared belief that ageing inescapably causes severe cognitive decline) contribute to the deteriorating cognitive performances of healthy older adults, leading them to perform below their true abilities. The study described here is intended to test for the first time whether such stereotypes also impair patients' cognitive performances during neuropsychological examinations in memory clinics, resulting in overdiagnosis of aMCI. METHODS AND ANALYSIS: The ongoing study is a 4-year randomised clinical trial comparing patients' physiological stress and cognitive performances during neuropsychological testing in memory clinics. A total of 260 patients attending their first cognitive evaluation will be randomised to either a standard condition of test administration, assumed here to implicitly activate negative ageing stereotypes or a reduced-threat instruction condition designed to alleviate the anxiety arising from these stereotypes. Both groups will be tested with the same test battery and stress biomarkers. For 30 patients diagnosed with aMCI in each group (n=60), biomarkers of neurodegeneration and amyloidopathy will be used to distinguish between aMCI with normal versus abnormal AD biomarkers. A 9-month follow-up will be performed on all patients to identify those whose cognitive performances remain stable, deteriorate or improve. ETHICS AND DISSEMINATION: This protocol has been approved by the French National Agency for Medicines and Health Products Safety and the Sud-Est I French Ethics Committee (2017-A00946-47). Results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03138018.

Cognitive, Emotional and Psychological Manifestations in Amyotrophic Lateral Sclerosis at Baseline and Overtime: A Review.

It is now well recognized that, in addition to motor impairment, amyotrophic lateral sclerosis (ALS) may cause extra-motor clinical signs and symptoms. These can include the alteration of certain cognitive functions, impaired social cognition, and changes in the perception and processing of emotions. Where these extra-motor manifestations occur in ALS, they usually do so from disease onset. In about 10% of cases, the cognitive and behavioral changes meet the diagnostic criteria for frontotemporal dementia. The timecourse of behavioral and cognitive involvement in ALS is unclear. Whereas longitudinal studies have failed to show cognitive decline over time, some cross-sectional studies have demonstrated poorer cognitive performances in the advanced stages of the disease. Neuroimaging studies show that in ALS, extra-motor signs and symptoms are associated with specific brain lesions, but little is known about how they change over time. Finally, patients with ALS appear less depressed than might be expected, given the prognosis. Moreover, many patients achieve satisfactory psychosocial adjustment throughout the course of the disease, regardless of their degree of motor disability. There are scant longitudinal data on extra-motor impairment in ALS, and to our knowledge, no systematic review on this subject has yet been published. Even so, a better understanding of patients' clinical trajectory is essential if they are to be provided with tailored care and given the best possible support. We therefore undertook to review the evidence for extra-motor changes and their time course in ALS, in both the cognitive, emotional and psychological domains, with a view to identifying mechanisms that may help these patients cope with their disease.

Neurocognitive determinants of theory of mind across the adult lifespan.

Although theory of mind (ToM) has been extensively explored in aging, few studies have used the same tool to simultaneously assess and compare its cognitive and affective components. When we administered the Movie for Assessment of Social Cognition, a dynamic sequence of social scenes, to 60 healthy participants (20-75 years), we observed no different age-related decreases in both cognitive and affective ToM. While each component was associated with cognitive measures (i.e., episodic memory and processing speed were predictive of cognitive ToM, and recognition of facial emotion expressions and inhibition were predictive of affective ToM), mediation analyses showed that these measures only mediated the effect of age on affective ToM. Voxelwise regressions with grey-matter volume showed that the components partly rely on the same neural substrates, reflecting either ToM per se or other cognitive processes elicited by this multi-determinant task. We discuss the specific substrates of each ToM component, emphasising the importance of considering the impact of other aspects of cognition, present in more ecological situations, on ToM functioning.

Cross-sectional and longitudinal characterization of SCD patients recruited from the community versus from a memory clinic: subjective cognitive decline, psychoaffective factors, cognitive performances, and atrophy progression over time.

BACKGROUND: Subjective cognitive decline (SCD) defines a heterogeneous population, part of which having Alzheimer's disease (AD). We aimed at characterizing SCD populations according to whether or not they referred to a memory clinic, by assessing the factors associated with increased AD risk. METHODS: Seventy-eight cognitively unimpaired older adults from the IMAP+ study (Caen) were included, amongst which 28 healthy controls (HC) and 50 SCD recruited from the community (SCD-community; n = 23) or from a memory clinic (SCD-clinic; n = 27). Participants underwent cognitive, psychoaffective, structural MRI, FDG-PET, and amyloid-PET assessments. They were followed up over a mean period of 2.4 ± 0.8 years. The groups were compared in terms of baseline and follow-up levels of SCD (self- and informant-reported), cognition, subclinical anxiety and depression, and atrophy progression over time. We also investigated SCD substrates within each SCD group through the correlations between self-reported SCD and other psychometric and brain measures. RESULTS: Compared to HC, both SCD groups showed similar cognitive performances but higher informant-reported SCD and anxiety. Compared to SCD-community, SCD-clinic showed higher informant-reported SCD, depression score, and atrophy progression over time but similar brain amyloid load. A significant increase over time was found for depression in the SCD-community and for self-reported praxis-domestic activities SCD factor in the SCD-clinic. Higher self-reported SCD correlated with (i) lower grey matter volume and higher anxiety in SCD-community, (ii) greater informant-reported SCD in SCD-clinic, and (iii) lower glucose metabolism in both SCD groups. CONCLUSIONS: Higher subclinical depression and informant-reported SCD specifically characterize the SCD group that refers to a memory clinic. The same group appears as a frailer population than SCD-community as they show greater atrophy progression over time. Yet, both the SCD groups were quite similar otherwise including for brain amyloid load and the SCD-community showed increased depression score over time. Altogether, our findings highlight the relevance of assessing psychoaffective factors and informant-reported SCD in SCD populations and point to both differences and similarities in SCD populations referring or not to a memory clinic.