Life-long music practice and executive control in older adults: An event-related potential study

Lower cognitive reserve is related to worse working memory performance in older adults after mTBI. An ERP study

OBJECTIVE

Older adults (OA) after mild traumatic brain injury (mTBI) have a high risk of developing persistent post-injury cognitive impairments. Lower pre-morbid cognitive reserve (CR) is increasingly investigated as a risk factor for cognitive dysfunction in OA. However, how CR protects against effects of mTBI at the brain level remains largely understudied.

METHODS

We examined 22 OA who sustained mTBI (mean 67.69 years, SD 5.11) in the sub-acute phase and 15 age- and CR-matched healthy OA (mean 68 years, SD 5.55) performing a three-level visual N-back task using electroencephalography. We calculated inverse efficiency scores of performance from accuracy and reaction times. Event-related potentials served as neurocognitive correlates of attentional (P2) and working memory (P3) processing.

RESULTS

Overall, mTBI OA performed worse than healthy OA (p = 0.031). Lower CR generally decreased performance (p < 0.001). Furthermore, with increasing task difficulty, task performance was more affected by CR (p = 0.004). At the brain level, P2 amplitude was lower in mTBI OA than in healthy OA (p = 0.05). There was no clear effect of CR on P2 or P3 measures.

CONCLUSION

As mTBI OA with lower CR performed worse on a working-memory task, lower CR may be a risk factor for worse recovery after mTBI in this group.

The impact of music training on temporal order processing in Mandarin Chinese sentence reading: Evidence from event-related potentials (ERPs)

The objective of this study was to investigate the impact of music training on the processing of temporal order in Mandarin sentence reading using event-related potentials (ERPs). Two-clause sentences with temporal connectives ("before" or "after") were presented to both musicians and non-musicians. Additionally, a verbal N-back task was utilized to evaluate the participants' working memory capacities. The findings revealed that musicians, but not nonmusicians, demonstrated a more negative amplitude in the second clauses of "before" sentences compared with "after" sentences. In the N-back task, musicians exhibited faster reaction times than nonmusicians in the two-back condition. Furthermore, a correlation was observed between the ERP amplitude differences (before vs. after) and reaction time differences in the N-back task (0-back vs. 2-back) among musicians. These findings suggested that music training enhances the depth of temporal order processing, potentially mediated by improvements in working memory capacity.

Cognitive resilience/reserve: Myth or reality? A review of definitions and measurement methods

INTRODUCTION

This review examines the concept of cognitive reserve (CR) in relation to brain aging, particularly in the context of dementia and its early stages. CR refers to an individual's ability to maintain or regain cognitive function despite brain aging, damage, or disease. Various factors, including education, occupation complexity, leisure activities, and genetics are believed to influence CR.

METHODS

We revised the literature in the context of CR. A total of 842 articles were identified, then we rigorously assessed the relevance of articles based on titles and abstracts, employing a systematic approach to eliminate studies that did not align with our research objectives.

RESULTS

We evaluate-also in a critical way-the methods commonly used to define and measure CR, including sociobehavioral proxies, neuroimaging, and electrophysiological and genetic measures. The challenges and limitations of these measures are discussed, emphasizing the need for more targeted research to improve the understanding, definition, and measurement of CR.

CONCLUSIONS

The review underscores the significance of comprehending CR in the context of both normal and pathological brain aging and emphasizes the importance of further research to identify and enhance this protective factor for cognitive preservation in both healthy and neurologically impaired older individuals.

HIGHLIGHTS

This review examines the concept of cognitive reserve in brain aging, in the context of dementia and its early stages. We have evaluated the methods commonly used to define and measure cognitive reserve. Sociobehavioral proxies, neuroimaging, and electrophysiological and genetic measures are discussed. The review emphasizes the importance of further research to identify and enhance this protective factor for cognitive preservation.

The impact of music making on neural efficiency & dual-task walking performance in healthy older adults

Music making is linked to improved cognition and related neuroanatomical changes in children and adults; however, this has been relatively under-studied in aging. The purpose of this study was to assess neural, cognitive, and physical correlates of music making in aging using a dual-task walking (DTW) paradigm. Study participants (N = 415) were healthy adults aged 65 years or older, including musicians (n = 70) who were identified by current weekly engagement in musical activity. A DTW paradigm consisting of single- and dual-task conditions, as well as portable neuroimaging (functional near-infrared spectroscopy), was administered. Outcome measures included neural activation in the prefrontal cortex assessed across task conditions by recording changes in oxygenated hemoglobin, cognitive performance, and gait velocity. Linear mixed effects models examined the impact of music making on outcome measures in addition to moderating their change between task conditions. Across participants (53.3% women; 76 ± 6.55 years), neural activation increased from single- to dual-task conditions (p < 0.001); however, musicians demonstrated attenuated activation between a single cognitive interference task and dual-task walking (p = 0.014). Musicians also displayed significantly smaller decline in behavioral performance (p < 0.001) from single- to dual-task conditions and faster gait overall (p = 0.014). Given evidence of lower prefrontal cortex activation in the context of similar or improved behavioral performance, results indicate the presence of enhanced neural efficiency in older adult musicians. Furthermore, improved dual-task performance in older adult musicians was observed. Results have important clinical implications for healthy aging, as executive functioning plays an essential role in maintaining functional ability in older adulthood.

The effects of musical instrument training on fluid intelligence and executive functions in healthy older adults: A systematic review and meta-analysis

Intervention studiescombiningcognitive and motor demands have reported far-transfer cognitive benefits in healthy ageing. This systematic review and meta-analysis evaluated the effects of music and rhythm intervention on cognition in older adulthood. Inclusion criteria specified: 1) musical instrument training; 2) healthy, musically-naïve adults (≥60 years); 3) control group; 4) measure of executive function. Ovid, PubMed, Scopus and the Cochrane Library online databases were searched in August 2023. Data from thirteen studies were analysed (N = 502 participants). Study quality was assessed using the Cochrane Risk of Bias tool (RoB 2; Sterne et al., 2019). Random effects models revealed: a low effect on inhibition (d = 0.27,p = .0335); a low-moderate effect on switching (d = -0.39, p = .0021); a low-moderate effect on verbal category switching (d =0.39,p = .0166); and a moderate effect on processing speed (d = 0.47,p < .0001). No effect was found for selective visual attention, working memory, or verbal memory. With regards to overall bias, three studies were rated as "high", nine studies were rated as having "some concerns" and one was rated "low". The meta-analysis suggests that learning to play a musical instrument enhances attention inhibition, switching and processing speed in ageing.

Rhythmic musical activities may strengthen connectivity between brain networks associated with aging-related deficits in timing and executive functions

Brain aging and common conditions of aging (e.g., hypertension) affect networks important in organizing information, processing speed and action programming (i.e., executive functions). Declines in these networks may affect timing and could have an impact on the ability to perceive and perform musical rhythms. There is evidence that participation in rhythmic musical activities may help to maintain and even improve executive functioning (near transfer), perhaps due to similarities in brain regions underlying timing, musical rhythm perception and production, and executive functioning. Rhythmic musical activities may present as a novel and fun activity for older adults to stimulate interacting brain regions that deteriorate with aging. However, relatively little is known about neurobehavioral interactions between aging, timing, rhythm perception and production, and executive functioning. In this review, we account for these brain-behavior interactions to suggest that deeper knowledge of overlapping brain regions associated with timing, rhythm, and cognition may assist in designing more targeted preventive and rehabilitative interventions to reduce age-related cognitive decline and improve quality of life in populations with neurodegenerative disease. Further research is needed to elucidate the functional relationships between brain regions associated with aging, timing, rhythm perception and production, and executive functioning to direct design of targeted interventions.

Temporal deployment of attention in musicians: Evidence from an attentional blink paradigm

The generalization of music training to unrelated nonmusical domains is well established and may reflect musicians' superior ability to regulate attention. We investigated the temporal deployment of attention in musicians and nonmusicians using scalp-recording of event-related potentials in an attentional blink (AB) paradigm. Participants listened to rapid sequences of stimuli and identified target and probe sounds. The AB was defined as a probe identification deficit when the probe closely follows the target. The sequence of stimuli was preceded by a neutral or informative cue about the probe position within the sequence. Musicians outperformed nonmusicians in identifying the target and probe. In both groups, cueing improved target and probe identification and reduced the AB. The informative cue elicited a sustained potential, which was more prominent in musicians than nonmusicians over left temporal areas and yielded a larger N1 amplitude elicited by the target. The N1 was larger in musicians than nonmusicians, and its amplitude over the left frontocentral cortex of musicians correlated with accuracy. Together, these results reveal musicians' superior ability to regulate attention, allowing them to prepare for incoming stimuli, thereby improving sound object identification. This capacity to manage attentional resources to optimize task performance may generalize to nonmusical activities.

Differences in motor inhibition in young and older musicians and non-musicians at rest

Introduction

Older adults experience a decline in motor inhibition. These declines have been implicated in instrumental activities of daily living. However, studies have revealed that older musicians have behavioral and neurophysiological enhancements in various motor domains compared to non-musicians. This suggests that music training may delay the decline in motor inhibition with aging. Nevertheless, motor inhibition has not been studied in young or older musicians and non-musicians. Thus, the present study aimed to investigate the neurophysiological differences in motor inhibition in aging musicians and non-musicians.

Methods

A total of 19 healthy young adult musicians, 16 healthy young non-musicians, 13 healthy older adult musicians, and 16 healthy older adult non-musicians were recruited for the study. Transcranial magnetic stimulation single-pulse (SP) and short interval cortical inhibition (SICI) were performed at rest and then converted into inhibition percentage.

Results

We did not observe significant differences between young and older musicians and non-musicians in resting SP MEP. Older adults had lower resting SICI MEP than young adults. Older adults (36%) had a greater percentage of inhibition than young adults (16%). However, when controlling for background EMG activity, musicians had a lower inhibition percentage than non-musicians.

Discussion

The results revealed that, despite the greater use of spinal mechanisms, decreased SICI, and increased inhibition percentage in older adults, motor inhibitory circuitry remains intact and functional in both young and older musicians and non-musicians. Future studies will reveal whether there are differences in motor inhibition during movement in musicians across a person's lifespan.

Effects of a 10-week musical instrument training on cognitive function in healthy older adults: implications for desirable tests and period of training

Introduction

Previous studies have shown that musical instrument training programs of 16 or more weeks improve verbal memory (Logical Memory Test delayed recall), processing speed (Digit Symbol Coding Test), and executive function (Trail Making Test Part B) of musically untrained healthy older adults. However, it is unclear whether shorter-period instrument training can yield similar effects. We sought to (1) verify those results and (2) clarify if intervention effects could be detected using other measures such as reaction time.

Methods

Healthy older adults (mean age = 73.28 years) were pseudo-randomly assigned to an untrained control group (n = 30) or an intervention group (n = 30) that received a weekly 10-session musical instrument training program (using melodica). We conducted neuropsychological tests on which intervention effects or association with musical training were reported in previous studies. We newly included two reaction time tasks to assess verbal working memory (Sternberg task) and rhythm entrainment (timing task). Intervention effects were determined using a "group × time" analysis of variance (ANOVA).

Results

The intervention effects were detected on the reaction time in Sternberg task and phonological verbal fluency. Although intervention effects had been reported on Logical Memory test, Digit Symbol Coding Test and Trail Making Test in previous studies with longer training periods, the present study did not show such effects. Instead, the test-retest practice effect, indicated by significant improvement in the control group, was significant on these tests.

Discussion

The present results indicated the usefulness of working memory assessments (Verbal Fluency Test and Sternberg task) in detecting the effects of short-term melodica training in healthy older adults. The practice effect detected on those three tasks may be due to the shorter interval between pre- and post-intervention assessments and may have obscured intervention effects. Additionally, the findings suggested the requirement for an extended interval between pre- and post-tests to capture rigorous intervention effects, although this should be justified by a manipulation of training period.

Musical experience prior to traumatic exposure as a resilience factor: a conceptual analysis

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.

Identification and Illustration of Means to a Critical Assessment of Music and Health Research Literature

In 2019, the WHO released a scoping review investigating art therapies in evidence-based healthcare practices to identify and understand the gaps in the literature. However, the studies curated were not evaluated for their quality. To address this limitation, several assessment tools to critically appraise music-based research studies that investigate therapies pertaining to preventative healthcare were investigated. Two critical appraisal tools were selected for their robustness and appropriateness for the studies in question: the Joanna Briggs Institute checklists and the Music-Based Intervention Guidelines. These tools were tested by two assessors on a total of 23 music studies from the Preventative and Prevention Health section of the WHO report. Based on the requirements for each critical appraisal tool, seven studies received a full assessment utilizing both checklists. Of these seven, two studies scored on the higher index, indicating that the studies followed a detailed methodology to provide concrete and accurate results. The findings of the study highlighted the limitations of study designs and music-based interventions. With this information, beneficial recommendations for future research in this domain are provided to improve the quality of research, ensuring its place in evidence-based healthcare practices.

Is musical engagement enough to keep the brain young?

Music-making and engagement in music-related activities have shown procognitive benefits for healthy and pathological populations, suggesting reductions in brain aging. A previous brain aging study, using Brain Age Gap Estimation (BrainAGE), showed that professional and amateur-musicians had younger appearing brains than non-musicians. Our study sought to replicate those findings and analyze if musical training or active musical engagement was necessary to produce an age-decelerating effect in a cohort of healthy individuals. We scanned 125 healthy controls and investigated if musician status, and if musical behaviors, namely active engagement (AE) and musical training (MT) [as measured using the Goldsmiths Musical Sophistication Index (Gold-MSI)], had effects on brain aging. Our findings suggest that musician status is not related to BrainAGE score, although involvement in current physical activity is. Although neither MT nor AE subscales of the Gold-MSI are predictive for BrainAGE scores, dispositional resilience, namely the ability to deal with challenge, is related to both musical behaviors and sensitivity to musical pleasure. While the study failed to replicate the findings in a previous brain aging study, musical training and active musical engagement are related to the resilience factor of challenge. This finding may reveal how such musical behaviors can potentially strengthen the brain's resilience to age, which may tap into a type of neurocognitive reserve.

Music training modulates theta brain oscillations associated with response suppression

There is growing interest in developing training programs to mitigate cognitive decline associated with normal aging. Here, we assessed the effect of 3-month music and visual art training programs on the oscillatory brain activity of older adults using a partially randomized intervention design. High-density electroencephalography (EEG) was measured during the pre- and post-training sessions while participants completed a visual GoNoGo task. Time-frequency representations were calculated in regions of interest encompassing the visual, parietal, and prefrontal cortices. Before training, NoGo trials generated greater theta power than Go trials from 300 to 500 ms post-stimulus in mid-central and frontal brain areas. Theta power indexing response suppression was significantly reduced after music training. There was no significant difference between pre- and post-test for the visual art or the control group. The effect of music training on theta power indexing response suppression was associated with reduced functional connectivity between prefrontal, visual, and auditory regions. These results suggest that theta power indexes executive control mechanisms in older adults. Music training affects theta power and functional connectivity associated with response suppression. These findings contribute to a better understanding of inhibitory control ability in older adults and the neuroplastic effects of music interventions.

Time of Day Effects on Inhibitory Functioning: Cognitive and Neural Evidence of Sundowning in Amnestic Mild Cognitive Impairment

Background: Amnestic mild cognitive impairment (aMCI), a prodromal phase of Alzheimer’s disease (AD), is characterized by episodic memory dysfunction, but inhibitory deficits have also been commonly reported. Time of day (TOD) effects have been confirmed in 1) healthy aging on cognitive processes such as inhibitory control, and 2) on behavior in AD (termed the sundowning effect), but no such research has addressed aMCI. Objective: The present study examined the impact of TOD on the behavioral and electrophysiological correlates of inhibition in 54 individuals with aMCI and 52 healthy controls (HCs), all of morning chronotype. Methods: Participants were randomly assigned to complete two inhibition tasks (Go-NoGo and Flanker) during their optimal (morning) or non-optimal (evening) TOD, while electroencephalography was recorded. Results: Both tasks elicited changes in N2 and P3 event-related potential (ERP) components, which commonly index inhibitory functioning. Analyses showed that the Go-NoGo difference in P3 amplitude was reduced in individuals with aMCI relative to HCs. Compared to HCs, the Flanker difference in P3 amplitude was also reduced and coincided with more errors in the aMCI group. Notably, these behavioral and ERP differences were exaggerated in the non-optimal TOD relative to the optimal TOD. Conclusion: Findings confirm the presence of inhibition deficits in aMCI and provide novel evidence of sundowning effects on inhibitory control in aMCI. Results reinforce the need to consider the influences of TOD in clinical assessments involving individuals with aMCI.

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.

Benefits of choir singing on complex auditory encoding in the aging brain: An ERP study

Aging is accompanied by difficulties in auditory information processing, especially in more complex sound environments. Choir singing requires efficient processing of multiple sound features and could, therefore, mitigate the detrimental effects of aging on complex auditory encoding. We recorded auditory event-related potentials during passive listening of sounds in healthy older adult (≥ 60 years) choir singers and nonsinger controls. We conducted a complex oddball condition involving encoding of abstract regularities in combinations of pitch and location features, as well as in two simple oddball conditions, in which only either the pitch or spatial location of the sounds was varied. We analyzed change-related mismatch negativity (MMN) and obligatory P1 and N1 responses in each condition. In the complex condition, the choir singers showed a larger MMN than the controls, which also correlated with better performance in a verbal fluency test. In the simple pitch and location conditions, the choir singers had smaller N1 responses compared to the control subjects, whereas the MMN responses did not differ between groups. These results suggest that regular choir singing is associated both with more enhanced encoding of complex auditory regularities and more effective adaptation to simple sound features.

Working-Memory, Alpha-Theta Oscillations and Musical Training in Older Age: Research Perspectives for Speech-on-speech Perception

During the normal course of aging, perception of speech-on-speech or “cocktail party” speech and use of working memory (WM) abilities change. Musical training, which is a complex activity that integrates multiple sensory modalities and higher-order cognitive functions, reportedly benefits both WM performance and speech-on-speech perception in older adults. This mini-review explores the relationship between musical training, WM and speech-on-speech perception in older age (> 65 years) through the lens of the Ease of Language Understanding (ELU) model. Linking neural-oscillation literature associating speech-on-speech perception and WM with alpha-theta oscillatory activity, we propose that two stages of speech-on-speech processing in the ELU are underpinned by WM-related alpha-theta oscillatory activity, and that effects of musical training on speech-on-speech perception may be reflected in these frequency bands among older adults.

The Effects of Aging and Time of Day on Inhibitory Control: An Event-Related Potential Study

Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one’s chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.

Electroencephalography, Magnetoencephalography, and Cognitive Reserve: A Systematic Review

OBJECTIVE

Cognitive reserve (CR) is the capacity to adapt to (future) brain damage without any or only minimal clinical symptoms. The underlying neuroplastic mechanisms remain unclear. Electrocorticography (ECOG), electroencephalography (EEG), and magnetoencephalography (MEG) may help elucidate the brain mechanisms underlying CR, as CR is thought to be related to efficient utilization of remaining brain resources. The purpose of this systematic review is to collect, evaluate, and synthesize the findings on neural correlates of CR estimates using ECOG, EEG, and MEG.

METHOD

We examined articles that were published from the first standardized definition of CR. Eleven EEG and five MEG cross-sectional studies met the inclusion criteria: They concerned original research, analyzed (M)EEG in humans, used a validated CR estimate, and related (M)EEG to CR. Quality assessment was conducted using an adapted form of the Newcastle-Ottawa scale. No ECOG study met the inclusion criteria.

RESULTS

A total of 1383 participants from heterogeneous patient, young and older healthy groups were divided into three categories by (M)EEG methodology: Eight (M)EEG studies employed event-related fields or potentials, six studies analyzed brain oscillations at rest (of which one also analyzed a cognitive task), and three studies analyzed brain connectivity. Various CR estimates were employed and all studies compared different (M)EEG measures and CR estimates. Several associations between (M)EEG measures and CR estimates were observed.

CONCLUSION

Our findings support that (M)EEG measures are related to CR estimates, particularly in healthy individuals. However, the character of this relationship is dependent on the population and task studied, warranting further studies.

Moderate-Intensity Physical Activity, Music and Art Activities Preserved Cognitive Health in Older Adults: An Argument for Social Prescribing Solution

Introduction: Rates of dementia are projected to increase over the coming years as global populations age. Without a treatment to slow the progression of dementia, many health policies are focusing on preventing dementia by slowing the rate of cognitive decline with age. However, it is unclear which lifestyle changes in old age meaningfully reduce the rate of cognitive decline associated with aging. Objectives: Use existing, multi-year longitudinal health data to determine if engagement in a variety of different lifestyle activities can slow the rate of cognitive decline as older adults age. Method: Data from the English Longitudinal Study of Aging was analyzed using a quasi-experimental, efficient matched-pair design inspired by the clinical trial methodology. Changes in short-term memory scores were assessed over a multi-year interval for groups who undertook one of 11 different lifestyle activities, compared to control groups matched across confounding socioeconomic and lifestyle factors. Results: Two factors, moderate-intensity physical activity and learning activities, resulted in significant positive impact on cognitive function. Conclusion: Our analysis brings cognitive benefit arguments in favor of two lifestyle activities, moderate-intensity physical activity and learning activities, while rejecting other factors advanced by the literature such as vigorous-intensity physical activity. Those findings justify and encourage the development of new lifestyle health programs by health authorities and bring forward the new health system solution, social prescribing.

Electrophysiological Proxy of Cognitive Reserve Index

Cognitive reserve (CR) postulates that individual differences in task performance can be attributed to differences in the brain’s ability to recruit additional networks or adopt alternative cognitive strategies. Variables that are descriptive of lifetime experience such as socioeconomic status, educational attainment, and leisure activity are common proxies of CR. CR is mostly studied using neuroimaging techniques such as functional MRI (fMRI) in which case individuals with a higher CR were observed to activate a smaller brain network compared to individuals with a lower CR, when performing a task equally effectively (higher efficiency), and electroencephalography (EEG) where a particular EEG component (P300) that reflects the attention and working memory load, has been targeted. Despite the contribution of multiple factors such as age, education (formal and informal), working, leisure, and household activities in CR formation, most neuroimaging studies, and those using EEG in particular, focus on formal education level only. The aim of the current EEG study is to investigate how the P300 component, evoked in response to an oddball paradigm, is associated with other components of CR besides education, such as working and leisure activity in older adults. We have used hereto a recently introduced CR index questionnaire (CRIq) that quantifies both professional and leisure activities in terms of their cognitive demand and number of years practiced, as well as a data-driven approach for EEG analysis. We observed complex relationships between CRIq subcomponents and P300 characteristics. These results are especially important given that, unlike previous studies, our measurements (P300 and CRIq) do not require active use of the same executive function and, thus, render our results free of a collinearity bias.

Is there a dose-response relationship between musical instrument playing and later-life cognition? A cohort study using EPIC-Norfolk data

INTRODUCTION

Musical instrument playing provides intellectual stimulation, which is hypothesised to generate cognitive reserve that protects against cognitive impairment. Studies to date have classified musicianship as a binary entity. This investigation draws on the dataset of the European Prospective Investigation of Cancer Norfolk study to examine the effect of frequency of playing on later-life cognition.

METHODS

We compared three categorisations of self-reported musical playing frequency in late mid-life (12-month period) against cognitive performance measured after a 4-11 year delay, adjusted for relevant health and social confounders. Logistic regression models estimated the adjusted association between frequency of musical playing and the likelihood of being in the top and bottom cognitive deciles.

RESULTS

A total of 5,693 participants (745 musicians) provided data on music playing, cognition and all co-variables. Classification of musicianship by frequency of playing demonstrated key differences in socio-demographic factors. Musicians outperformed non-musicians in cognition generally. Compared with non-musicians, frequent musicians had 80% higher odds of being in the top cognitive decile (OR 1.80 [95% CI 1.19-2.73]), whereas musicians playing at any frequency had 29% higher odds (95% CI 1.03-1.62). There was evidence of a threshold effect, rather than a linear dose-response relationship.

DISCUSSION

This study supports a positive association between late mid-life musical instrument playing and later-life cognition, although causation cannot be assumed. Musicians playing frequently demonstrated the best cognition. 'Musicians' are a heterogeneous group and frequency of music playing seems a more informative measure than binary classification. Ideally, this more nuanced measure would be collected for different life course phases.

Musical Training and Brain Volume in Older Adults

Musical practice, including musical training and musical performance, has been found to benefit cognitive function in older adults. Less is known about the role of musical experiences on brain structure in older adults. The present study examined the role of different types of musical behaviors on brain structure in older adults. We administered the Goldsmiths Musical Sophistication Index, a questionnaire that includes questions about a variety of musical behaviors, including performance on an instrument, musical practice, allocation of time to music, musical listening expertise, and emotional responses to music. We demonstrated that musical training, defined as the extent of musical training, musical practice, and musicianship, was positively and significantly associated with the volume of the inferior frontal cortex and parahippocampus. In addition, musical training was positively associated with volume of the posterior cingulate cortex, insula, and medial orbitofrontal cortex. Together, the present study suggests that musical behaviors relate to a circuit of brain regions involved in executive function, memory, language, and emotion. As gray matter often declines with age, our study has promising implications for the positive role of musical practice on aging brain health.

Long-Term Music Exposure Prevents Age-Related Cognitive Deficits in Rats Independently of Hippocampal Neurogenesis

Cognitive decline appears across aging. While some studies report beneficial effects of musical listening and practice on cognitive aging, the underlying neurobiological mechanisms remain unknown. This study aims to determine whether chronic (6 h/day, 3 times/week) and long-lasting (4-8 months) music exposure, initiated at middle age in rats (15 months old), can influence behavioral parameters sensitive to age effects and reduce age-related spatial memory decline in rats. Spontaneous locomotor, circadian rhythmic activity, and anxiety-like behavior as well as spatial working and reference memory were assessed in 14-month-old rats and then after 4 and 8 months of music exposure (19 and 23 months old, respectively). Spatial learning and reference memory data were followed up by considering cognitive status of animals prior to music exposure (14 months old) given by K-means clustering of individual Z-score. Hippocampal cell proliferation and brain-derived neurotrophic factor (BDNF) level in the hippocampus and frontal cortex were measured. Results show that music exposure differentially rescues age-related deficits in spatial navigation tasks according to its duration without affecting spontaneous locomotor, circadian rhythmic activity, and anxiety-like behavior. Hippocampal cell proliferation as well as hippocampal and frontal cortex BDNF levels was not affected by music across aging. Cognitive improvement by music in aging rats may require distinct neurobiological mechanisms than hippocampal cell proliferation and BDNF.

Do Musicians Have Better Mnemonic and Executive Performance Than Actors? Influence of Regular Musical or Theater Practice in Adults and in the Elderly

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.

Audio Feedback for Device-Supported Balance Training: Parameter Mapping and Influencing Factors

Recent studies suggest that real-time auditory feedback is an effective method to facilitate motor learning. The evaluation of the parameter mapping (sound-to-movement mapping) is a crucial, yet frequently neglected step in the development of audio feedback. We therefore conducted two experiments to evaluate audio parameters with target finding exercises designed for balance training. In the first experiment with ten participants, five different audio parameters were evaluated on the X-axis (mediolateral movement). Following that, in a larger experiment with twenty participants in a two-dimensional plane (mediolateral and anterior-posterior movement), a basic and synthetic audio model was compared to a more complex audio model with musical characteristics. Participants were able to orient themselves and find the targets with the audio models. In the one-dimensional condition of experiment one, percussion sounds and synthetic sound wavering were the overall most effective audio parameters. In experiment two, the synthetic model was more effective and better evaluated by the participants. In general, basic sounds were more helpful than complex (musical) sound models. Musical abilities and age were correlated with certain exercise scores. Audio feedback is a promising approach for balance training and should be evaluated with patients. Preliminary evaluation of the respective parameter mapping is highly advisable.

Music Making and Neuropsychological Aging: A Review

Aging is associated with a decline in social understanding and general cognition. Both are integral to wellbeing and rely on similar brain regions. Thus, as the population ages, there is a growing need for knowledge on the types of activities that maintain brain health in older adulthood. Active engagement in music making might be one such activity because it places a demand on brain networks tapping into multisensory integration, learning, reward, and cognition. It has been hypothesized that this demand may promote plasticity in the frontal and temporal lobes by taxing cognitive abilities and, hence, increase resistance to age-related neurodegeneration. We examine research relevant to this hypothesis and note that there is a lack of intervention studies with a well-matched control condition and random assignment. Thus, we discuss potential causal mechanisms underlying training-related neuropsychological changes, and provide suggestions for future research. It is argued that although music training might be a valuable tool for supporting healthy neuropsychological aging and mental wellbeing, well-controlled intervention studies are necessary to provide clear evidence.

New Perspectives on Music in Rehabilitation of Executive and Attention Functions

Modern music therapy, starting around the middle of the twentieth century was primarily conceived to promote emotional well-being and to facilitate social group association and integration. Therefore, it was rooted mostly in social science concepts. More recently, music as therapy began to move decidedly toward perspectives of neuroscience. This has been facilitated by the advent of neuroimaging techniques that help uncover the therapeutic mechanisms for non-musical goals in the brain processes underlying music perception, cognition, and production. In this paper, we focus on executive function (EF) and attentional processes (AP) that are central for cognitive rehabilitation efforts. To this end, we summarize existing behavioral as well as neuroimaging and neurophysiological studies in musicians, non-musicians, and clinical populations. Musical improvisation and instrumental playing may have some potential for EF/AP stimulation and neurorehabilitation. However, more neuroimaging studies are needed to investigate the neural mechanisms for the active musical performance. Furthermore, more randomized clinical trials combined with neuroimaging techniques are warranted to demonstrate the specific efficacy and neuroplasticity induced by music-based interventions.

How is musical activity associated with cognitive ability in later life?

Research has suggested that individuals who play a musical instrument throughout adulthood have better preserved executive function. However, mixed results have been found for associations between musical activity and visuo-spatial abilities, and less is known about associations with fluid intelligence. We explored differences between musicians (N = 30) and non-musicians (N = 30) aged 60-93 years old across a range of neuropsychological measures of cognitive function. Musicians performed significantly better than non-musicians on all domains, which remained after adjusting for age, gender, educational history, languages spoken and physical activity. As a cross-sectional comparison, the results should not be overstated; however, they are consistent with findings suggesting learning a musical instrument throughout the life course may be associated with cognitive benefits. Identifying potential lifestyle factors that have cognitive benefits in later life, such as musical experience, is an important step in developing intervention strategies for cognitive aging.

Absolute Pitch and Musical Expertise Modulate Neuro-Electric and Behavioral Responses in an Auditory Stroop Paradigm

Musicians have considerable experience naming pitch-classes with verbal (e.g., Doh, Ré, and Mi) and semiotic tags (e.g., musical notation). On the one end of the spectrum, musicians can identify the pitch of a piano tone or quality of a chord without a reference tone [i.e., absolute pitch (AP) or relative pitch], which suggests strong associations between the perceived pitch information and verbal labels. Here, we examined the strength of this association using auditory versions of the Stroop task while neuro-electric brain activity was measured using high-density electroencephalography. In separate blocks of trials, participants were presented with congruent or incongruent auditory words from English language (standard auditory Stroop), Romanic solemnization, or German key lexicons (the latter two versions require some knowledge of music notation). We hypothesized that musically trained groups would show greater Stroop interference effects when presented with incongruent musical notations than non-musicians. Analyses of behavioral data revealed small or even non-existent congruency effects in musicians for solfège and keycodes versions of the Stroop task. This finding was unexpected and appears inconsistent with the hypothesis that musical training and AP are associated with high strength response level associations between a perceived pitch and verbal label. The analyses of event-related potentials revealed three temporally distinct modulations associated with conflict processing. All three modulations were larger in the auditory word Stroop than in the other two versions of the Stroop task. Only AP musicians showed significant congruity effects around 450 and 750 ms post-stimulus when stimuli were presented as Germanic keycodes (i.e., C or G). This finding suggests that AP possessors may process alpha-numeric encodings as word forms with a semantic value, unlike their RP possessing counterparts and non-musically trained individuals. However, the strength of musical conditional associations may not exceed that of standard language in speech.

When I'm 64: A review of instrumental music-making and brain health in later life

According to the World Health Organization, global average life expectancy increased by 5.5 years between 2000 and 2016. This is the greatest increase in life expectancy since the 1960s. Identifying lifestyle choices which can be implemented in later life to support brain health are imperative given the increasing prevalence of age-related neurodegenerative diseases, such as dementia. Music-making, specifically instrumental music-making, has been suggested to support cognition function and emotional wellbeing in later life. This review will distinguish instrumental music-making from other musical activities (i.e. singing or listening to music), specifically focusing on its influence on cognitive function in later life and its contribution to the emotional wellbeing and quality of life. This review will also explore the viability of instrumental music-making as an intervention to support brain health in later life.

Rationale and protocol of the ENGAGE study: a double-blind randomized controlled preference trial using a comprehensive cohort design to measure the effect of a cognitive and leisure-based intervention in older adults with a memory complaint

BACKGROUND

Leisure activities can be both enjoyable and cognitively stimulating, and participation in such activities has been associated with reduced age-related cognitive decline. Thus, integrating stimulating leisure activities in cognitive training programs may represent a powerful and innovative approach to promote cognition in older adults at risk of dementia. The ENGAGE study is a randomized controlled, double-blind preference trial with a comprehensive cohort design that will test the efficacy and long-term impact of an intervention that combines cognitive training and cognitively stimulating leisure activities.

METHODS

One hundred and forty-four older adults with a memory complaint will be recruited in Montreal and Toronto. A particular effort will be made to reach persons with low cognitive reserve. Participants will be randomly assigned to one of two conditions: cognitive + leisure training (ENGAGE-MUSIC/SPANISH) or active control (ENGAGE-DISCOVERY). The ENGAGE-MUSIC/SPANISH training will include teaching of mnemonic and attentional control strategies, casual videogames selected to train attention, and classes in music or Spanish as a second language. The ENGAGE-DISCOVERY condition will comprise psychoeducation on cognition and the brain, low-stimulating casual videogames and documentary viewing with discussions. To retain the leisure aspect of the activities, participants will be allowed to exclude either music or Spanish at study entry if they strongly dislike one of these activities. Participants randomized to ENGAGE-MUSIC/SPANISH who did not exclude any activity will be assigned to music or Spanish based on a second random assignment. Training will be provided in 24 2-h sessions over 4 months. Outcomes will be measured at baseline, at 4-month follow-up, and at 24-month follow-up. The primary outcome will be cognitive performance on a composite measure of episodic memory (delayed recall scores for words and face-name associations) measured at baseline and at the 4-month follow-up. Secondary outcomes will include a composite measure of attention (speed of processing, inhibition, dual tasking, and shifting), psychological health, activities of daily living, and brain structure and function and long-term maintenance measured at the 24-month follow-up. Information on cognitive reserve proxies (education and lifestyle questionnaires), sex and genotype (apolipoprotein (Apo)E4, brain-derived neurotrophic factor (BDNF), and catechol-O-methyltransferase (COMT)) will be collected and considered as moderators of training efficacy.

DISCUSSION

This study will test whether a program combining cognitive training with stimulating leisure activities can increase cognition and reduce cognitive decline in persons at risk of dementia.

TRIAL REGISTRATION

NCT03271190 . Registered on 5 September 2017.

Efficiency of attentional networks in musicians and non-musicians

Music is a complex and properly human skill. Previous studies indicate that systematic musical training induces specific structural brain changes and improves audio-motor functions. However, whether these benefits can transfer into functional improvements of attentional skills is still little known. To shed light on this issue, in the present study we explored the relationship between long-term musical training and the efficiency of the attentional system. We used the attention network test (ANT) to compare the performance of the alerting, orienting and executive attentional networks of professional pianists against a matched group of non-musician adults. We found that musicians were significantly faster to respond across the ANT task, and that the executive attentional network was more efficient in musicians than non-musicians. We found no differences in the efficiency of the alerting and orienting networks between both groups. Interestingly, we found that the efficiency of the executive system improves with the years of musical training, even when controlling for age. We also found that the three attentional networks of the non-musicians were functionally independent. However, in the case of the musicians, the efficiency of the alerting and orienting systems was associated. These findings provide evidence of a potential transfer effect from systematic musical training into inhibitory attentional control.

Music and Visual Art Training Modulate Brain Activity in Older Adults

Cognitive decline is an unavoidable aspect of aging that impacts important behavioral and cognitive skills. Training programs can improve cognition, yet precise characterization of the psychological and neural underpinnings supporting different training programs is lacking. Here, we assessed the effect and maintenance (3-month follow-up) of 3-month music and visual art training programs on neuroelectric brain activity in older adults using a partially randomized intervention design. During the pre-, post-, and follow-up test sessions, participants completed a brief neuropsychological assessment. High-density EEG was measured while participants were presented with auditory oddball paradigms (piano tones, vowels) and during a visual GoNoGo task. Neither training program significantly impacted psychometric measures, compared to a non-active control group. However, participants enrolled in the music and visual art training programs showed enhancement of auditory evoked responses to piano tones that persisted for up to 3 months after training ended, suggesting robust and long-lasting neuroplastic effects. Both music and visual art training also modulated visual processing during the GoNoGo task, although these training effects were relatively short-lived and disappeared by the 3-month follow-up. Notably, participants enrolled in the visual art training showed greater changes in visual evoked response (i.e., N1 wave) amplitude distribution than those from the music or control group. Conversely, those enrolled in music showed greater response associated with inhibitory control over the right frontal scalp areas than those in the visual art group. Our findings reveal a causal relationship between art training (music and visual art) and neuroplastic changes in sensory systems, with some of the neuroplastic changes being specific to the training regimen.

Instrument Playing as a Cognitive Intervention Task for Older Adults: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to review studies that applied musical instrument playing as an intervention to improve cognitive functioning of older adults with and without cognitive impairment. English-language articles published between 1990 and 2018 were searched using electronic databases. Music therapy journals were also hand searched for relevant research. Inclusion criteria for participants were older adults, ages 60 years and older, and any clinical diagnosis of cognitive impairment had to be due to aging. Searches used combinations of the following keywords: older adults, instrument playing, and cognitive outcomes measures. A total of 10 studies that met the inclusion criteria were included in the final analysis: five studies with healthy older adults, two with older adults with mild cognitive impairment (MCI), two studies with older adults with dementia, and one study with both healthy older adults and older adults with MCI. The results of this meta-analysis demonstrated that different types of cognitive involvement were demanded from instrument playing. Furthermore, depending on the type of involvement, a target cognitive domain was found to be differentially impacted by the instrument playing intervention. This study supports using different types of instrument playing for interventions targeting specific cognitive domains of older adults with varying levels of cognitive aging.

Musical practice as an enhancer of cognitive function in healthy aging - A systematic review and meta-analysis

Aging is accompanied by cognitive decline, although recent research indicates that the rate of decline depends on multiple lifestyle factors. One of such factors is musical practice, an activity that involves several sensory and motor systems and a wide range of high-level cognitive processes. This paper describes the first systematic review and meta-analysis, to our knowledge, of the impact of musical practice on healthy neurocognitive aging. The inclusion criteria for the review required that studies were empirical works in English or Spanish that they explored the effects of musical practice on older people; they included an assessment of cognitive functions and/or an assessment of brain status; and they included a sample of participants aged 59 years or older with no cognitive impairment or brain damage. This review led to the selection of 13 studies: 9 correlational studies involving older musicians and non-musicians and 4 experimental studies involving short-term musical training programs. The results of the meta-analysis showed cognitive and cerebral benefits of musical practice, both in domain-specific functions (auditory perception) and in other rather domain-general functions. Moreover, these benefits seem to protect cognitive domains that usually decline with aging and boost other domains that do not decline with aging. The origin of these benefits may reside, simultaneously, in the specific training of many of these cognitive functions during musical practice (specific training mechanism), in the improvement of compensatory cognitive processes (specific compensatory mechanism), and in the preservation of general functions with a global influence on others, such as perceptual capacity, processing speed, inhibition and attention (general compensatory mechanism). Therefore, musical practice seems to be a promising tool to reduce the impact of cognitive problems associated to aging.

Sensorimotor lateralization scaffolds cognitive specialization

In this chapter, we review hemispheric differences for sensorimotor function and cognitive abilities. Specifically, we examine the left-hemisphere specialization for visuomotor control and its interplay with language, executive function, and musical training. Similarly, we discuss right-hemisphere lateralization for haptic processing and its relationship to spatial and numerical processing. We propose that cerebral lateralization for sensorimotor functions served as a foundation for the development of higher cognitive abilities and their hemispheric functional specialization. We further suggest that sensorimotor and cognitive functions are inextricably linked. Based on the studies discussed in this chapter our view is that sensorimotor control serves as a loom upon which the fibers of language, executive function, spatial, and numerical processing are woven together to create the fabric of cognition.

Different neural activities support auditory working memory in musicians and bilinguals

Musical training and bilingualism benefit executive functioning and working memory (WM)-however, the brain networks supporting this advantage are not well specified. Here, we used functional magnetic resonance imaging and the n-back task to assess WM for spatial (sound location) and nonspatial (sound category) auditory information in musician monolingual (musicians), nonmusician bilinguals (bilinguals), and nonmusician monolinguals (controls). Musicians outperformed bilinguals and controls on the nonspatial WM task. Overall, spatial and nonspatial WM were associated with greater activity in dorsal and ventral brain regions, respectively. Increasing WM load yielded similar recruitment of the anterior-posterior attention network in all three groups. In both tasks and both levels of difficulty, musicians showed lower brain activity than controls in superior prefrontal frontal gyrus and dorsolateral prefrontal cortex (DLPFC) bilaterally, a finding that may reflect improved and more efficient use of neural resources. Bilinguals showed enhanced activity in language-related areas (i.e., left DLPFC and left supramarginal gyrus) relative to musicians and controls, which could be associated with the need to suppress interference associated with competing semantic activations from multiple languages. These findings indicate that the auditory WM advantage in musicians and bilinguals is mediated by different neural networks specific to each life experience.

Potential Cognitive Benefits From Playing Music Among Cognitively Intact Older Adults: A Scoping Review

The aging population is growing rapidly, raising rates of cognitive impairment, which makes strategies for protection against cognitive impairment increasingly important. There is little evidence indicating highly effective interventions preventing or slowing onset of cognitive impairment. Music playing influences brain and cognitive function, activating multiple brain areas and using cognitive and motor functions as well as multiple sensory systems, simultaneously. The purpose of this study was to review the current evidence related to playing a musical instrument being a potentially protective mechanism against cognitive decline among older adults. Using scoping review procedures, four databases were searched. Paired reviewers analyzed articles for content, design, and bias. Eleven studies met study criteria and were included in the review. All studies showed that music playing was correlated with positive outcomes on cognitive ability; more high-quality research is needed in this area to understand mechanisms behind potential cognitive protection of music.

Got Rhythm? Better Inhibitory Control Is Linked with More Consistent Drumming and Enhanced Neural Tracking of the Musical Beat in Adult Percussionists and Nonpercussionists

Musical rhythm engages motor and reward circuitry that is important for cognitive control, and there is evidence for enhanced inhibitory control in musicians. We recently revealed an inhibitory control advantage in percussionists compared with vocalists, highlighting the potential importance of rhythmic expertise in mediating this advantage. Previous research has shown that better inhibitory control is associated with less variable performance in simple sensorimotor synchronization tasks; however, this relationship has not been examined through the lens of rhythmic expertise. We hypothesize that the development of rhythm skills strengthens inhibitory control in two ways: by fine-tuning motor networks through the precise coordination of movements "in time" and by activating reward-based mechanisms, such as predictive processing and conflict monitoring, which are involved in tracking temporal structure in music. Here, we assess adult percussionists and nonpercussionists on inhibitory control, selective attention, basic drumming skills (self-paced, paced, and continuation drumming), and cortical evoked responses to an auditory stimulus presented on versus off the beat of music. Consistent with our hypotheses, we find that better inhibitory control is correlated with more consistent drumming and enhanced neural tracking of the musical beat. Drumming variability and the neural index of beat alignment each contribute unique predictive power to a regression model, explaining 57% of variance in inhibitory control. These outcomes present the first evidence that enhanced inhibitory control in musicians may be mediated by rhythmic expertise and provide a foundation for future research investigating the potential for rhythm-based training to strengthen cognitive function.

Mild cognitive impairment and structural brain abnormalities in a sexagenarian with a history of childhood traumatic brain injury

In this report, we present a case study involving an older, female patient with a history of pediatric traumatic brain injury (TBI). Magnetic resonance imaging and diffusion tensor imaging volumes were acquired from the volunteer in question, her brain volumetrics and morphometrics were extracted, and these were then systematically compared against corresponding metrics obtained from a large sample of older healthy control (HC) subjects as well as from subjects in various stages of mild cognitive impairment (MCI) and Alzheimer disease (AD). Our analyses find the patient's brain morphometry and connectivity most similar to those of patients classified as having early-onset MCI, in contrast to HC, late MCI, and AD samples. Our examination will be of particular interest to those interested in assessing the clinical course in older patients having suffered TBI earlier in life, in contradistinction to those who experience incidents of head injury during aging.