Mathilde Groussard

Alzheimer’s disease is a neurodegenerative disorder marked by a progressive decline in episodic memory and impaired encoding of new information. While hippocampal atrophy is a hallmark of the disease, several observations suggest that some mechanisms may remain preserved, including familiarity-based recognition. Artistic items, such as music and paintings, are particularly suitable to elicit these spared processes, as they engage reward, emotional, and implicit learning networks that remain intact in this condition. However, the extent to which patients with moderate to severe Alzheimer’s disease can learn new information in these domains remains unclear. Thirty-three patients with Alzheimer’s disease (79.30 ± 5.82 years; mean Mini-Mental State Examination [MMSE] score = 14.76 ± 5.42) and 24 healthy control participants (77.17 ± 4.62 years; mean MMSE score = 28.83 ± 0.92) were included in the protocol. A data-driven stratification based on neuropsychological scores identified two subgroups of patients, classified as moderate and severe cognitive impairments. Participants first completed repeated exposure sessions to unknown musical and pictorial items until they reported a sense of familiarity, assessed by a six-point scale designed for this population. One to two days later, a recognition session during which target items and distractor items were presented was conducted; participants’ performance was also evaluated using the familiarity scale. Structural MRI was acquired to quantify hippocampal atrophy and examine the relationship between grey matter volume and recognition performance. Despite significantly different learning rates across clinical groups (cumulative link mixed model, all pairwise comparisons P < 0.001), 31 patients out of 33 reached the learning criterion for at least one of the two artistic materials. In the recognition session, pairwise comparisons confirmed that all clinical groups significantly discriminated target from distractor items (cumulative link mixed model, all pairwise comparisons P < 0.001), with a gradient of discrimination consistent with disease severity, indicating preserved but modulated familiarity-based recognition. Structural imaging confirmed substantial hippocampal atrophy in both patient subgroups relative to healthy controls (P < 0.001). Multiple regression revealed that higher familiarity scores in recognition session were associated with greater grey matter volume in the right caudate nucleus (cluster-level, PFWE < 0.05). These findings demonstrate that patients with moderate to severe Alzheimer’s disease retain the ability to encode new musical and pictorial information despite pronounced hippocampal atrophy. Familiarity-based mechanisms, supported by subcortical regions, appear to underpin this preserved learning and may offer promising perspectives for care in patients with Alzheimer’s disease.

Background: Among aging individuals, some develop Alzheimer's disease (AD) while others remain cognitively stable. Understanding how structural and functional brain changes interact, could clarify this heterogeneity particularly among individuals at increased risk for AD. Objective: This study aims to explore how structure-function connectivity changes relate to subsequent long-term cognitive trajectories in older adults with SMC and varying amyloid burden. Methods: We analyzed data from the INSIGHT-preAD cohort, which includes older individuals with subjective cognitive complaints followed neuropsychologically over five years. Multiplex connectome integrating resting-state EEG functional connectivity and diffusion-weighted imaging-based structural connectivity was used to characterize brain network organization. We computed the multiplex participation coefficient (PC) as an index of structure-function similarity and examined its association with individual cognitive trajectories across the follow-up period. Results: Significant differences in multiplex connectivity were observed among amyloid positive participants who later progressed to AD compared to amyloid positive stable (e.g., non-progressors) and amyloid negative controls. Specifically, higher PC values in the delta band were observed in amyloid positive individuals who later developed AD. This pattern, particularly within the default mode network, was associated with subsequent cognitive decline suggesting that delta band structure-function similarity may represent a potential candidate marker of cognitive vulnerability and progression in AD. Conclusions: Most studies investigating AD have primarily examined functional or structural connectivity separately. By integrating both modalities using a multiplex approach, our study provides interesting preliminary evidence that structure-function connectivity may capture network-level changes associated with cognitive trajectories along AD continuum.

The Music Ensemble dataset is a large-scale, cross-national database that provides detailed information about the musical, cognitive, personality, and demographic profiles of young adult musicians and nonmusicians. Data were collected from 1438 participants (aged 18–30) across thirty-five research sites in Europe, North America, South America, and Australia. Participants completed an in-person, in-lab battery of objective tests, including measures of verbal, visuospatial and musical short-term memory, executive functions (updating component), nonverbal reasoning, verbal comprehension, and music perception skills. The battery also included standardized and custom self-report questionnaires assessing music sophistication, music reward, personality traits, socioeconomic status, and demographic characteristics. Music Ensemble was preregistered, and the research protocol followed a standardized procedure across sites. The dataset also includes a large subsample of musicians and nonmusicians that are pair-matched for age, gender, and education (678 pairs). It enables well-powered investigations into the relationship between musical expertise and individual differences in cognition, personality, and demographic variables. It is also suitable for training in statistical and psychometric methods.

Resilience mechanisms can be dynamically triggered throughout the lifecourse by resilience factors in order to prevent individuals from developing stress-related pathologies such as posttraumatic stress disorder (PTSD). Some interventional studies have suggested that listening to music and musical practice after experiencing a traumatic event decrease the intensity of PTSD, but surprisingly, no study to our knowledge has explored musical experience as a potential resilience factor before the potential occurrence of a traumatic event. In the present conceptual analysis, we sought to summarize what is known about the concept of resilience and how musical experience could trigger two key mechanisms altered in PTSD: emotion regulation and cognitive control. Our hypothesis is that the stimulation of these two mechanisms by musical experience during the pre-traumatic period could help protect against the symptoms of emotional dysregulation and intrusions present in PTSD. We then developed a new framework to guide future research aimed at isolating and investigating the protective role of musical experience regarding the development of PTSD in response to trauma. The clinical application of this type of research could be to develop pre-trauma training that promotes emotional regulation and cognitive control, aimed at populations at risk of developing PTSD such as healthcare workers, police officers, and military staffs.

Background: Alzheimer’s disease (AD) and Korsakoff’s syndrome (KS) are two major neurocognitive disorders characterized by amnesia but AD is degenerative while KS is not. The objective is to compare regional volume deficits within the Papez circuit in AD and KS, considering AD progression. Methods: 18 KS patients, 40 AD patients (20 with Moderate AD (MAD) matched on global cognitive deficits with KS patients and 20 with Severe AD (SAD)), and 70 healthy controls underwent structural MRI. Volumes of the hippocampi, thalami, cingulate gyri, mammillary bodies (MB) and mammillothalamic tracts (MTT) were extracted. Results: For the cingulate gyri, and anterior thalamic nuclei, all patient groups were affected compared to controls but did not differ between each other. Smaller volumes were observed in all patient groups compared to controls in the mediodorsal thalamic nuclei and MB, but these regions were more severely damaged in KS than AD. MTT volumes were damaged in KS only. Hippocampi were affected in all patient groups but more severely in the SAD than in the KS and MAD. Conclusions: There are commonalities in the pattern of volume deficits in KS and AD within the Papez circuit with the anterior thalamic nuclei, cingulate cortex and hippocampus (in MAD only) being damaged to the same extent. The specificity of KS relies on the alteration of the MTT and the severity of the MB shrinkage. Further comparative studies including other imaging modalities and a neuropsychological assessment are required.

Objectives To compare regional volume deficits within the Papez circuit in Alzheimer’s disease (AD) and Korsakoff’s syndrome (KS), taking into account the neurodegenerative nature of AD. Methods 18 KS patients, 40 AD patients (20 with Moderate AD (MAD) matched on cognitive deterioration with KS patients and 20 with Severe AD (SAD)), and 70 healthy controls underwent structural MRI examination. Volumes of the hippocampi, thalami, cingulate gyri, mammillary bodies (MB) and mammillothalamic tracts (MTT) were extracted. Results For the anterior and posterior cingulate gyri, and anterior thalamic nuclei, all patient groups were significantly affected compared to controls but did not differ between each other. Lower volumes were observed in all patient groups compared to controls in the entire thalamus, mediodorsal thalamic nuclei and MB, but these regions were more severely damaged in KS compared to AD. MTT volumes were significantly damaged in KS only. Hippocampi were affected in all patient groups but more severely in the SAD than in the KS and MAD. Interpretation The specificity of KS compared to AD relies on the severity of the MB and mediodorsal nuclei shrinkage, as well as the atrophy of the MTT. Several nodes of the Papez circuit were damaged to the same extent in AD and KS: the anterior thalamic nuclei, the cingulate cortex and the hippocampus (in MAD only). Our results encourage considering common mechanisms in the pathophysiology of amnesia regardless of etiology and question the relevance of the classical distinction between hippocampal and diencephalic amnesia.

The effects of musical practice on cognition are well established yet rarely compared with other kinds of artistic training or expertise. This study aims to compare the possible effect of musical and theater regular practice on cognition across the lifespan. Both of these artistic activities require many hours of individual or collective training in order to reach an advanced level. This process requires the interaction between higher-order cognitive functions and several sensory modalities (auditory, verbal, visual and motor), as well as regular learning of new pieces. This study included participants with musical or theater practice, and healthy controls matched for age (18–84 years old) and education. The objective was to determine whether specific practice in these activities had an effect on cognition across the lifespan, and a protective influence against undesirable cognitive outcomes associated with aging. All participants underwent a battery of cognitive tasks that evaluated processing speed, executive function, fluency, working memory, verbal and visual long-term memories, and non-verbal reasoning abilities. Results showed that music and theater artistic practices were strongly associated with cognitive enhancements. Participants with musical practice were better in executive functioning, working memory and non-verbal reasoning, whereas participants with regular acting practice had better long-term verbal memory and fluency performance. Thus, taken together, results suggest a differential effect of these artistic practices on cognition across the lifespan. Advanced age did not seem to reduce the benefit, so future studies should focus on the hypothetical protective effects of artistic practice against cognitive decline.

Through this review of 25 clinical and experimental works on long-term musical memories in Alzheimer’s disease (AD) patients, we attempt to clarify the conceptual understanding of musical memories, identify their evolution across the stages of the pa