Explicit and implicit memory for music in healthy older adults and patients with mild Alzheimer's disease

The underlying roles and neurobiological mechanisms of music-based intervention in Alzheimer's disease: A comprehensive review

Non-pharmacological therapy has gained popularity in the intervention of Alzheimer's disease (AD) due to its apparent therapeutic effectiveness and the limitation of biological drug. A wealth of research indicates that music interventions can enhance cognition, mood and behavior in individuals with AD. Nonetheless, the underlying mechanisms behind these improvements have yet to be fully and systematically delineated. This review aims to holistically review how music-based intervention (MBI) ameliorates abnormal emotion, cognition decline, and behavioral changes in AD patients. We cover several key dimensions: the regulation of MBIs on cerebral blood flow (CBF), their impact on neurotransmission (including GABAergic and monoaminergic transmissions), modulation of synaptic plasticity, and hormonal release. Additionally, we summarize the clinical applications and limitations of active music-based intervention (AMBI), passive music-based intervention (PMBI), and hybrid music-based intervention (HMBI). This thorough analysis enhances our understanding of the role of MBI in AD and supports the development of non-pharmacological therapeutic strategies.

Neural correlates of musical familiarity: a functional magnetic resonance study

Existing neuroimaging studies on neural correlates of musical familiarity often employ a familiar vs. unfamiliar contrast analysis. This singular analytical approach reveals associations between explicit musical memory and musical familiarity. However, is the neural activity associated with musical familiarity solely related to explicit musical memory, or could it also be related to implicit musical memory? To address this, we presented 130 song excerpts of varying familiarity to 21 participants. While acquiring their brain activity using functional magnetic resonance imaging (fMRI), we asked the participants to rate the familiarity of each song on a five-point scale. To comprehensively analyze the neural correlates of musical familiarity, we examined it from four perspectives: the intensity of local neural activity, patterns of local neural activity, global neural activity patterns, and functional connectivity. The results from these four approaches were consistent and revealed that musical familiarity is related to the activity of both explicit and implicit musical memory networks. Our findings suggest that: (1) musical familiarity is also associated with implicit musical memory, and (2) there is a cooperative and competitive interaction between the two types of musical memory in the perception of music.

Music Therapy Enhances Episodic Memory in Alzheimer's and Mixed Dementia: A Double-Blind Randomized Controlled Trial

Objective: This study aimed to assess whether a music therapy (MT) intervention could improve memory decline in older adults with and without cognitive impairment. A dual-retrieval model of episodic memory was employed to estimate memory processes. Methods: Forty-three older adults with a mean age of 76.49 years (n = 25 with Alzheimer's disease (AD) and mixed dementia, and n = 18 healthy older adults) were randomly selected for the experimental and control groups. The study design was a double-blind randomized controlled clinical trial and a certified music therapist delivered the MT. The primary outcomes were measures of working memory, episodic memory, and autobiographical memory. Results: In the primary outcome measures, MT effects were restricted to episodic memory measures like the Figure Memory Test of the BCSB and the Speech and Sing Memory Test. In both tests, the experimental group improved from pre-test to post-test in delayed recall, but in the Speech and Sing Memory Test, the improvement was restricted to the AD and mixed dementia group. MT had no effects on the secondary outcome measures. Conclusions: These findings suggest that a structured MT intervention can be promising for rehabilitating episodic memory in older adults with dementia.

Exploring why "memory loss" is a misleading descriptor of people living with dementia and can lead to dysfunctional care

Amidst goals for prevention and improved treatment for people living with dementia, much remains needed to enhance the quality of life of those currently diagnosed, especially the transfer of accurate information from professionals to the public. Although many healthcare professionals understand the various types of memory and which are likely to be more affected than others during the progression of dementia, lay persons are more frequently unaware of that important information. The terms used to describe the symptoms of dementia can have a great impact on perceptions of faculties that are absent, compromised, or preserved. Understanding the nuances of preserved memory faculties and other cognitive abilities retained by persons with dementia is important in this regard. The term "memory loss" as a descriptor of the syndrome of dementia and ascribing it to persons with dementia connotes an inability to form new memories and participate in meaningful social interactions, which is detrimental to their personhood. From a multidisciplinary approach drawn from neurology, neurobiology, psychology, and case vignettes, we aim herein to highlight the ways in which the term "memory loss" can be inaccurate, counterproductive and potentially promote dementia-related misperceptions, malignant positioning and malignant social psychology. Persons with dementia unequivocally struggle with explicit memory, or recalling on demand, but retain implicit memory, as evidenced by research and everyday actions. Therefore, we propose the use of alternative medical language to reflect accurately memory impairment and preservation of some important memory capabilities.

Sensogenomics of music and Alzheimer's disease: An interdisciplinary view from neuroscience, transcriptomics, and epigenomics

Introduction

The relationship between music and Alzheimer's disease (AD) has been approached by different disciplines, but most of our outstanding comes from neuroscience.

Methods

First, we systematically reviewed the state-of-the-art of neuroscience and cognitive sciences research on music and AD (>100 studies), and the progress made on the therapeutic impact of music stimuli in memory. Next, we meta-analyzed transcriptomic and epigenomic data of AD patients to search for commonalities with genes and pathways previously connected to music in genome association, epigenetic, and gene expression studies.

Results

Our findings indicate that >93% of the neuroscience/ cognitive sciences studies indicate at least one beneficial effect of music on patients with neurodegenerative diseases, being improvements on memory and cognition the most frequent outcomes; other common benefits were on social behavior, mood and emotion, anxiety and agitation, quality of life, and depression. Out of the 334 music-related genes, 127 (38%) were found to be linked to epigenome/transcriptome analysis in AD (vs. healthy controls); some of them (SNCA, SLC6A4, ASCC2, FTH1, PLAUR and ARHGAP26) have been reported to be associated e.g. with musical aptitude and music effect on the transcriptome. Other music-related genes (GMPR, SELENBP1 and ADIPOR1) associated to neuropsychiatric, neurodegenerative diseases and music performance, emerged as hub genes in consensus co-expression modules detected between AD and music estimulated transcriptomes. In addition, we found connections between music, AD and dopamine related genes, with SCNA being the most remarkable - a gene previously associated with learning and memory, and neurodegenerative disorders (e.g., Parkinson's disease and AD).

Discussion

The present study indicate that the vast majority of neuroscientific studies unambiguously show that music has a beneficial effect on health, being the most common benefits relevant to Alzheimer's disease. These findings illuminate a new roadmap for genetic research in neurosciences, and musical interventions in AD and other neurodegenerative conditions.

An integrative approach to dementia care

As the aging population continues to increase, Alzheimer's disease and related dementias are becoming a global health crisis. The burdens experienced by the person living with dementia, their caregivers, healthcare, and society persist unabated. Persons with dementia represent an important population in need of a tenable care plan. Caregivers need the tools with which to properly care for these persons and to mitigate their own stress response. A viable healthcare model utilizing integrated approaches to care for persons with dementia is in overwhelming demand. While much research is focused on a cure, it is equally important to address the difficulties faced by those currently affected. One approach is to incorporate interventions to increase quality of life within the caregiver-patient dyad via a comprehensive integrative model. Improving daily life of the persons with dementia, along with their caregivers and loved ones may aid in attenuating the pervasive psychological and physical impacts of this disease. A focus on interventions that provide neural and physical stimulation may facilitate quality of life in this regard. The subjective experience of this disease is challenging to capture. The relationship between neurocognitive stimulation and quality of life is at least, in part, therefore still uncertain. This narrative review aims to explore the efficacy and evidence-base of an integrative approach to dementia care in facilitating optimal cognition and quality of life outcomes. These approaches will be reviewed alongside person-centered care that is fundamental to integrative medicine, including exercise; music; art and creativity; nutrition; psychosocial engagement; memory training; and acupuncture.

Music experience predicts episodic memory performance in older adult instrumental musicians

OBJECTIVE

Previous research suggests that there is a relationship between music lessons early in life and cognitive functioning in late life. The current study examined 1) how lifestyle factors, including music lessons, physical and social activity, and health predict late life cognition and 2) how unique music training variables (e.g., hours practiced, years in lessons, age of acquisition) predicted cognitive scores for older adults.

METHODS

Participants completed a neuropsychological battery examining major cognitive domains, and completed questionnaires on music experience, physical and social activity, and physician diagnosed health factors.

RESULTS

Results suggested that belonging to the musician group predicted scores on executive functioning, language, and visual spatial ability. Among instrumental musicians, number of years in formal training and current number of hours playing per week predicted scores on verbal memory. Age of acquisition was not a significant predictor of cognitive functioning.

CONCLUSIONS

Music training significantly predicted scores on tests of executive function, visual spatial ability, and language, above and beyond other variables, including current age and health and lifestyle factors. The number of years of formal training predicted scores on verbal learning and memory, with significant implications for aging. The results are discussed in the context of cognitive aging and music education.

Assessing music-related memory in people with dementia: a scoping review

OBJECTIVES

There are various type of music-related memory and different aspects of impairment caused by dementia. The purpose of this scoping review was to identify methods and map key concepts in assessing music-related memory in people with dementia.

METHOD

The review was conducted using the five steps in the framework proposed by Arksey and O'Malley. Databases and other sources were searched to identify relevant studies, and data selection and abstraction were performed.

RESULTS

A total of 35 studies that met the selection criteria were finally selected and analysed. We confirmed that the assessment of music-related memory can be systematically classified as assessing short-term or long-term memory, explicit or implicit memory, depending on the type of memory. Regarding the key concept of assessing music-related memory, we mapped a conceptual framework for the interrelationships between music and memory from a person-centered perspective.

CONCLUSION

Comprehensive information on music-related memory obtained through the assessment will be helpful for a holistic understanding of the person with dementia. In addition, it will provide meaningful information for specific planning and application of musical experiences that can be effectively used in music therapy. Further research is needed to establish the reliability and validity of the assessment.

Preserved Consciousness in Alzheimer's Disease and Other Dementias: Caregiver Awareness and Communication Strategies

Alzheimer's disease is an insidious onset neurodegenerative syndrome without effective treatment or cure. It is rapidly becoming a global health crisis that is overwhelming healthcare, society, and individuals. The clinical nature of neurocognitive decline creates significant challenges in bidirectional communication between caregivers and persons with Alzheimer's disease (AD) that can negatively impact quality-of-life. This paper sought to understand how and to what extent would awareness training about the levels of consciousness in AD influence the quality-of-life interactions in the caregiver-patient dyad. A literature review of multiple databases was conducted utilizing a transdisciplinary approach. The sum of findings indicates a positive relationship between enhanced caregiver awareness and training, positive interactions, and improved QOL measures among patients and caregivers. A multidirectional relationship was found among healthcare policies, training and education resources, caregivers, and persons with AD. Specifically, the current lack of policy and inadequate training and educational resources has various detrimental effects on patients and caregivers, while improvements in training and education of caregivers yields positive outcomes in communication and QOL. Furthermore, evidence of preserved consciousness in persons with AD was demonstrated from multiple disciplines, including neurobiological, psychological, and biopsychosocial models. The literature further revealed several methods to access the preserved consciousness in persons with AD and related dementias, including sensory, emotional, and cognitive stimulations. The evidence from the literature suggests a reframed approach to our understanding and treatment of persons with AD is not only warranted, but crucial to address the needs of those affected by AD.

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.