Frontal Lobe Functions in Normal Aging: Metacognition, Autonomy, and Quality of Life

Causal relationship between multiparameter brain MRI phenotypes and age: evidence from Mendelian randomization

To explore the causal relationship between age and brain health (cortical atrophy, white matter integrity, white matter hyperintensities and cerebral microbleeds in various brain regions) related multiparameter imaging features using two-sample Mendelian randomization. Age was determined as chronological age of the subject. Cortical volume, white matter micro-integrity, white matter hyperintensity volume and cerebral microbleeds of each brain region were included as phenotypes for brain health. Age and imaging of brain health related genetic data were analysed to determine the causal relationship using inverse-variance weighted model, validated by heterogeneity and horizontal pleiotropy variables. Age is causally related to increased volumes of white matter hyperintensities (β = 0.151). For white matter micro-integrity, fibres of the inferior cerebellar peduncle (axial diffusivity β = -0.128, orientation dispersion index β = 0.173), cerebral peduncle (axial diffusivity β = -0.136), superior fronto-occipital fasciculus (isotropic volume fraction β = 0.163) and fibres within the limbic system were causally deteriorated. We also detected decreased cortical thickness of multiple frontal and temporal regions (P < 0.05). Microbleeds were not related with aging (P > 0.05). Aging is a threat of brain health, leading to cortical atrophy mainly in the frontal lobes, as well as the white matter degeneration especially abnormal hyperintensity and deteriorated white matter integrity around the hippocampus.

Measures of individual differences in adult theory of mind: A systematic review

Theory of mind (ToM), the ability to understand and reason about mental states, has been extensively studied in young children and clinical populations. A growing interest in examining ToM in adults has emerged over the past two decades, but the extent to which existing measures are suitable for studying adults, especially in detecting individual differences, remains understudied. In this systematic review of 273 studies, 75 measures used to investigate individual differences in adults' ToM were identified. Their sensitivity to individual differences, reliability, and validity were examined. Results suggest that ceiling effects were prevalent, and there was limited evidence to establish the reliability or validity of these measures due to the lack of reports of psychometric properties. Interrelations among measures were inconsistent. These findings highlight the need for future empirical and theoretical work to broaden the evidence base regarding psychometric properties of measures, to develop new measures, and to lay out more specific hypotheses about the relevance of ToM for different social outcomes.

Cognitive Functions, Theory of Mind Abilities, and Personality Dispositions as Potential Predictors of the Detection of Reciprocity in Deceptive and Cooperative Contexts through Different Age Groups

Reciprocity is a fundamental element in social interactions and implies an adequate response to the previous actions of our interactant. It is thus crucial to detect if a person is cooperating, deceiving, or cheating, to properly respond. However, older adults have been shown to have a lower ability to detect reciprocity compared to younger adults, partially tying this decline to cognitive functions. Another likely association to reciprocity in literature is made with personality dispositions, i.e., agreeableness, altruism, and empathic concern, and Theory of Mind (ToM). Consequently, the present study investigated age-related differences in the detection of the different components of reciprocity, as well as examined the predictors of reciprocity, such as cognitive measures, personality dispositions, and true and false beliefs in young (n = 98; 20-39 years), middle-aged (n = 106; 40-64 years), and older adults (n = 103; 65-96 years). The Mind Picture Story-Theory of Mind Questionnaire was used to measure the reciprocity components and true and false beliefs in each group. This study reported a significant decline in reciprocity detection from adults aged 65 years old and over. Additionally, the ability to detect reciprocity was significantly linked to cognitive functioning and ToM across all age groups, especially in older adults.

Musicianship-Related Structural and Functional Cortical Features Are Preserved in Elderly Musicians

Background

Professional musicians are a model population for exploring basic auditory function, sensorimotor and multisensory integration, and training-induced neuroplasticity. The brain of musicians exhibits distinct structural and functional cortical features; however, little is known about how these features evolve during aging. This multiparametric study aimed to examine the functional and structural neural correlates of lifelong musical practice in elderly professional musicians.

Methods

Sixteen young musicians, 16 elderly musicians (age >70), and 15 elderly non-musicians participated in the study. We assessed gray matter metrics at the whole-brain and region of interest (ROI) levels using high-resolution magnetic resonance imaging (MRI) with the Freesurfer automatic segmentation and reconstruction pipeline. We used BrainVoyager semiautomated segmentation to explore individual auditory cortex morphotypes. Furthermore, we evaluated functional blood oxygenation level-dependent (BOLD) activations in auditory and non-auditory regions by functional MRI (fMRI) with an attentive tone-listening task. Finally, we performed discriminant function analyses based on structural and functional ROIs.

Results

A general reduction of gray matter metrics distinguished the elderly from the young subjects at the whole-brain level, corresponding to widespread natural brain atrophy. Age- and musicianship-dependent structural correlations revealed group-specific differences in several clusters including superior, middle, and inferior frontal as well as perirolandic areas. In addition, the elderly musicians exhibited increased gyrification of auditory cortex like the young musicians. During fMRI, the elderly non-musicians activated predominantly auditory regions, whereas the elderly musicians co-activated a much broader network of auditory association areas, primary and secondary motor areas, and prefrontal and parietal regions like, albeit weaker, the young musicians. Also, group-specific age- and musicianship-dependent functional correlations were observed in the frontal and parietal regions. Moreover, discriminant function analysis could separate groups with high accuracy based on a set of specific structural and functional, mainly temporal and occipital, ROIs.

Conclusion

In conclusion, despite naturally occurring senescence, the elderly musicians maintained musicianship-specific structural and functional cortical features. The identified structural and functional brain regions, discriminating elderly musicians from non-musicians, might be of relevance for the aging musicians’ brain. To what extent lifelong musical activity may have a neuroprotective impact needs to be addressed further in larger longitudinal studies.

Activities of Daily Living and Categorization Skills of Elderly with Cognitive Deficit: A Preliminary Study

Cognitive dysfunction affects the performance of Activities of Daily Living (ADL) and the quality of life of people with these deficits and their caregivers. To the knowledge of the authors, to date, there are few studies that focus on knowing the relationship between personal autonomy and deductive reasoning and/or categorization skills, which are necessary for the performance of the ADL. The aim of this study was to explore the relationships between ADL and categorization skills in older people. The study included 51 participants: 31 patients with cognitive impairment and 20 without cognitive impairment. Two tests were administered to assess cognitive functions: (1) the Montreal Cognitive Assessment (MoCA); and (2) the digital version of Riska Object Classification test (ROC-d). In addition, the Routine Tasks Inventory-2 (RTI-2) was applied to determine the level of independence in activities of daily living. People with cognitive impairment performed poorly in categorization tasks with unstructured information (p = 0.006). Also, the results found a high correlation between cognitive functioning and the performance of ADLs (Physical ADL: r = 0.798; p < 0.001; Instrumental ADL: r = 0.740; p < 0.001), a moderate correlation between Physical ADLs and categorization skills (unstructured ROC-d: r = 0.547; p < 0.001; structured ROC-d: r = 0.586; p < 0.001) and Instrumental ADLs and categorization skills in older people (unstructured ROC-d: r = 0.510; p < 0.001; structured ROC-d: r = 0.463; p < 0.001). The ROC-d allows the assessment of categorization skills to be quick and easy, facilitating the assessment process by OT, as well as the accuracy of the data obtained.

Time for a Systems Biological Approach to Cognitive Aging?-A Critical Review

The underlying premise of current theories of cognitive decline with age tend to be primarily cognitive or biological explanations, with relatively few theories adequately integrating both aspects. Though literature has also emphasized the importance of several factors that contribute to cognitive aging including: (a) decline in sensory abilities; (b) the effect of motor speed on paper-pencil measures of cognitive speed; (c) the impact of level of education and physical activity; and (d) molecular biological changes that occur with age, these factors have seldom been implicated into any single theoretical model of cognitive aging. Indeed, such an integrated bio-cognitive model of aging has the potential to provide a more comprehensive understanding of attention, perception, learning, and memory across the lifespan. Thus, the aim of this review was to critically evaluate common theories of age-related cognitive decline and highlight the need for a more comprehensive systems neuroscience approach to cognitive aging.

Study of the theory of mind in normal aging: focus on the deception detection and its links with other cognitive functions

Detection of deception is crucial to avoid negative circumstances (financial frauds, social tricks) in daily living. Considering that this cognitive function is especially supported by the prefrontal cortex of the human brain and that these cerebral regions change with advanced age, deception detection may also change with aging. Our purpose is to study this complex ability and its potential links with other cognitive functions, such as the executive control, in normal aging. Thirty-five young adults (YA) aged from 20 to 40, thirty-five old adults (OA) aged from 65 to 79 and thirty very old adults (VOA) aged from 80 to 95 were involved in this study. We propose a novel neuropsychological test (inspired by Theory of Mind Picture Story task) assessing the ability to understand deceptive and cooperative interactions, and tasks involving executive processes (monitoring, task setting, flexibility) to all participants. Between-group analyses show that older participants performed worse than YA on deceptive, cooperative and mixed situations (involving deception and reciprocity) of our task. Significant correlations exist between the deception-cooperation detection and the executive functions. Our results show that these frontal abilities decline after 65 years, even more after 80 years, and they are involved on the deceptive-cooperative situations. The verbal IQ is also linked with the deception-cooperation detection. This suggests that mixed cognitive trainings would allow older adults to detect more easily bad intentions of others, to adjust their behavior to context and to achieve their goals with less risk.