Language in the aging brain: The network dynamics of cognitive decline and preservation

Predictors of Therapy Response in Chronic Aphasia: Building a Foundation for Personalized Aphasia Therapy

Chronic aphasia, a devastating impairment of language, affects up to a third of stroke survivors. Speech and language therapy has consistently been shown to improve language function in prior clinical trials, but few clinicially applicable predictors of individual therapy response have been identified to date. Consequently, clinicians struggle substantially with prognostication in the clinical management of aphasia. A rising prevalence of aphasia, in particular in younger populations, has emphasized the increasing demand for a personalized approach to aphasia therapy, that is, therapy aimed at maximizing language recovery of each individual with reference to evidence-based clinical recommendations. In this narrative review, we discuss the current state of the literature with respect to commonly studied predictors of therapy response in aphasia. In particular, we focus our discussion on biographical, neuropsychological, and neurobiological predictors, and emphasize limitations of the literature, summarize consistent findings, and consider how the research field can better support the development of personalized aphasia therapy. In conclusion, a review of the literature indicates that future research efforts should aim to recruit larger samples of people with aphasia, including by establishing multisite aphasia research centers.

Linguistic profiles of variants of primary progressive aphasia

BACKGROUND

Several subtypes of primary progressive aphasia (PPA) have been proposed. Most reports use small samples, and few have included Spanish-speaking participants.

AIM

To analyze the language profile and nonlinguistic deficits in a large sample of PPA Spanish monolingual participants.

METHOD

177 individuals were diagnosed with PPA in a sample consisting of 69 men and 108 women (M_age = 66.40 years, SD = 9.30). The participants were assessed using the Spanish versions of the Western Aphasia Battery Revised (SWAB-R) and the Boston Diagnostic Aphasia Examination (SBDAE). Non-verbal reasoning was evaluated with the Raven's Colored Progressive Matrices.

RESULTS

41.8% of the sample met the criteria for the logopenic variant (lvPPA), while 28.2% met the criteria for semantic (svPPA), 15.3% for lexical (lxvPPA), and 14.7% for nonfluent/agrammatic (nfvPPA) variants. Language difficulties were similar in all variants except for lxvPPA. Scores on Spontaneous Language, Auditory Comprehension, Repetition, and Naming were significantly higher for the lxvPPA group. Raven's Colored Progressive Matrices scores were significantly lower in lvPPA. Years of education correlated with all test scores, while age was negatively associated with naming. When the PPA variants were classified according to the traditional aphasia classification, discrepancies were evident. Furthermore, the most frequent type of aphasia was Amnesic, while the least frequent was Wernicke's aphasia.

CONCLUSION

The SWAB-R is useful in describing the clinical characteristics of aphasia for each variant of PPA, but quantitative scores from this battery are not capable of distinguishing between variants of PPA, with the exception of lxvPPA.

Socioeconomic status impacts cognitive and socioemotional processes in healthy ageing

Socioeconomic status (SES) negatively impacts cognitive and executive functioning in older adults, yet its effects on socioemotional abilities have not been studied in this population. Also, evidence on neurocognitive processes associated with ageing primarily comes from Western, educated, industrialized, rich, and democratic (WEIRD) populations, hindering the generalization of findings to persons from upper-middle- and low-middle-income countries, such as those of Latin America. Here, we compared the performance of low- and high-SES older adults from Argentina in cognitive state, executive functions, social cognition (emotion recognition and theory of mind), and counter-empathic social emotions (envy and Schadenfreude; displeasure at others' fortune and pleasure at others' misfortune, respectively). Subsequently, we developed a path analysis to test the relationship among those variables in a theoretically plausible model and tested the main paths via multiple regression analyses. Relative to the high-SES group, low-SES older adults showed poorer performance on all assessed domains. Convergent evidence from covariance analysis, path analysis, and linear regressions suggested that low-SES impact on socioemotional processes was not primary but mediated by cognitive and executive impairment. These findings offer the first characterization of SES impacts on cognitive and socioemotional processes in a non-WEIRD population and have relevant equity-related implications for brain health.

Verbal Training Induces Enhanced Functional Connectivity in Japanese Healthy Elderly Population

This study employs fMRI to examine the neural substrates of response to cognitive training in healthy old adults. Twenty Japanese healthy elders participated in a 4-week program and practiced a verbal articulation task on a daily basis. Functional connectivity analysis revealed that in comparison to age- and education-matched controls, elders who received the cognitive training demonstrated increased connectivity in the frontotemporal regions related with language and memory functions and showed significant correlations between the behavioral change in a linguistic task and connectivity in regions for goal-oriented persistence and lexical processing. The increased hippocampal connectivity was consistent with previous research showing efficacious memory improvement and change in hippocampal functioning. Moreover, the increased intra-network connectivity following cognitive training suggested an improved neural differentiation, in contrast to the inter-network activation pattern typical in the aging brain. This research not only validates the relationship of functional change in the frontal and temporal lobes to age-associated cognitive decline but also shows promise in turning neural change toward the right direction by cognitive training.

Effects of thalamic and basal ganglia deep brain stimulation on language-related functions - Conceptual and clinical considerations

Deep Brain Stimulation (DBS) is a therapy for various neurological movement disorders. It acts predominantly on motor symptoms, but may unfold a number of mostly subtle cognitive effects. In this regard, reports on particular language-related DBS sequels are comparably frequent, but difficult to overlook, given the heterogeneity of targeted structures in the brain, treated diseases, assessment methods and results reported. Accordingly, available knowledge was organized with respect to important aspects, such as the main DBS loci and surgical versus neuromodulatory therapy actions. Current views of biolinguistic underpinnings of the reviewed data, their clinical relevance and potential implications are discussed.

Evidence that ageing yields improvements as well as declines across attention and executive functions

Many but not all cognitive abilities decline during ageing. Some even improve due to lifelong experience. The critical capacities of attention and executive functions have been widely posited to decline. However, these capacities are composed of multiple components, so multifaceted ageing outcomes might be expected. Indeed, prior findings suggest that whereas certain attention/executive functions clearly decline, others do not, with hints that some might even improve. We tested ageing effects on the alerting, orienting and executive (inhibitory) networks posited by Posner and Petersen's influential theory of attention, in a cross-sectional study of a large sample (N = 702) of participants aged 58-98. Linear and nonlinear analyses revealed that whereas the efficiency of the alerting network decreased with age, orienting and executive inhibitory efficiency increased, at least until the mid-to-late 70s. Sensitivity analyses indicated that the patterns were robust. The results suggest variability in age-related changes across attention/executive functions, with some declining while others improve.

With a little help from familiar interlocutors: real-world language use in young and older adults

OBJECTIVES

Functional psychologists are concerned with the performance of cognitive activities in the real world in relation to cognitive changes in older age. Conversational contexts may mitigate the influence of cognitive aging on the cognitive activity of language production. This study examined effects of familiarity with interlocutors, as a context, on language production in the real world.

METHOD

We collected speech samples using iPhones, where an audio recording app (i.e. Electronically Activated Recorder [EAR]) was installed. Over 31,300 brief audio files (30-second long) were randomly collected across four days from 61 young and 48 healthy older adults in Switzerland. We transcribed the audio files that included participants' speech and manually coded for familiar interlocutors (i.e. significant other, friends, family members) and strangers. We computed scores of vocabulary richness and grammatical complexity from the transcripts using computational linguistics techniques.

RESULTS

Bayesian multilevel analyses showed that participants used richer vocabulary and more complex grammar when talking with familiar interlocutors than with strangers. Young adults used more diverse vocabulary than older adults and the age effects remained stable across contexts. Furthermore, older adults produced equally complex grammar as young adults did with the significant other, but simpler grammar than young adults with friends and family members.

CONCLUSION

Familiarity with interlocutors is a promising contextual factor for research on aging and language complexity in the real world. Results were discussed in the context of cognitive aging.

How the healthy ageing brain supports semantic binding during language comprehension

Semantic binding refers to constructing complex meaning based on elementary building blocks. Using electroencephalography (EEG), we investigated the age-related changes in modulations of oscillatory brain activity supporting lexical retrieval and semantic binding. Young and older adult participants were visually presented two-word phrases, which for the first word revealed a lexical retrieval signature (e.g., swift vs. swrfeq) and for the second word revealed a semantic binding signature (e.g., horse in a semantic binding "swift horse" vs. no binding "swrfeq horse" context). The oscillatory brain activity associated with lexical retrieval as well as semantic binding significantly differed between healthy older and young adults. Specifically for lexical retrieval, we found that different age groups exhibited opposite patterns of theta and alpha modulation, which as a combined picture suggest that lexical retrieval is associated with different and delayed signatures in older compared with young adults. For semantic binding, in young adults, we found a signature in the low-beta range centred around the target word onset (i.e., a smaller low-beta increase for binding relative to no binding), whereas in healthy older adults, we found an opposite binding signature about ~500 ms later in the low- and high-beta range (i.e., a smaller low- and high-beta decrease for binding relative to no binding). The novel finding of a different and delayed oscillatory signature for semantic binding in healthy older adults reflects that the integration of word meaning into the semantic context takes longer and relies on different mechanisms in healthy older compared with young adults.

Evidence of cerebral hemodynamic dysregulation in middle-aged APOE ε4 carriers: The PREVENT-Dementia study

Accumulating evidence suggests vascular dysregulation in preclinical Alzheimer's disease. In this study, cerebral hemodynamics and their coupling with cognition in middle-aged apolipoprotein ε4 carriers (APOEε4+) were investigated. Longitudinal 3 T T1-weighted and arterial spin labelling MRI data from 158 participants (40-59 years old) in the PREVENT-Dementia study were analysed (125 two-year follow-up). Cognition was evaluated using the COGNITO battery. Cerebral blood flow (CBF) and cerebrovascular resistance index (CVRi) were quantified for the flow territories of the anterior, middle and posterior cerebral arteries. CBF was corrected for underlying atrophy and individual hematocrit. Hemodynamic measures were the dependent variables in linear regression models, with age, sex, years of education and APOEε4 carriership as predictors. Further analyses were conducted with cognitive outcomes as dependent variables, using the same model as before with additional APOEε4 × hemodynamics interactions. At baseline, APOEε4+ showed increased CBF and decreased CVRi compared to non-carriers in the anterior and middle cerebral arteries, suggestive of potential vasodilation. Hemodynamic changes were similar between groups. Interaction analysis revealed positive associations between CBF changes and performance changes in delayed recall (for APOEε4 non-carriers) and verbal fluency (for APOEε4 carriers) cognitive tests. These observations are consistent with neurovascular dysregulation in middle-aged APOEε4+.

Digital medicine and the curse of dimensionality

Digital health data are multimodal and high-dimensional. A patient's health state can be characterized by a multitude of signals including medical imaging, clinical variables, genome sequencing, conversations between clinicians and patients, and continuous signals from wearables, among others. This high volume, personalized data stream aggregated over patients' lives has spurred interest in developing new artificial intelligence (AI) models for higher-precision diagnosis, prognosis, and tracking. While the promise of these algorithms is undeniable, their dissemination and adoption have been slow, owing partially to unpredictable AI model performance once deployed in the real world. We posit that one of the rate-limiting factors in developing algorithms that generalize to real-world scenarios is the very attribute that makes the data exciting-their high-dimensional nature. This paper considers how the large number of features in vast digital health data can challenge the development of robust AI models-a phenomenon known as "the curse of dimensionality" in statistical learning theory. We provide an overview of the curse of dimensionality in the context of digital health, demonstrate how it can negatively impact out-of-sample performance, and highlight important considerations for researchers and algorithm designers.

Age-Dependent Contribution of Domain-General Networks to Semantic Cognition

Aging is characterized by a decline of cognitive control. In semantic cognition, this leads to the paradox that older adults usually show poorer task performance than young adults despite their greater semantic knowledge. So far, the underlying neural changes of these behavioral differences are poorly understood. In the current neuroimaging study, we investigated the interaction of domain-specific and domain-general networks during verbal semantic fluency in young and older adults. Across age groups, task processing was characterized by a strong positive integration within the multiple-demand as well as between the multiple-demand and the default mode network during semantic fluency. However, the behavioral relevance of strengthened connectivity differed between groups: While within-network functional connectivity in both networks predicted greater efficiency in semantic fluency in young adults, it was associated with slower performance in older adults. Moreover, only young adults profited from connectivity between networks for their semantic memory performance. Our results suggest that the functional coupling of usually anticorrelated networks is critical for successful task processing, independent of age, when access to semantic memory is required. Furthermore, our findings lend novel support to the notion of reduced efficiency in the aging brain due to neural dedifferentiation in semantic cognition.

The ironic effect of older adults' increased task motivation: Implications for neurocognitive aging

Recent work suggests that most older adults who volunteer to take part in cognitive experiments are more motivated to do well than are undergraduate students. This empirical evidence is echoed by the impressions of cognitive aging researchers. We surveyed a large group (N = 88) of researchers asking about their perceptions of younger and older adults' motivation to take part in lab-based research. Not only were older adults seen as more motivated than younger adults, but researchers thought that the two groups participate for different reasons: younger adults to obtain course credit or monetary compensation, older adults to get a sense of their cognitive health, to further science, and out of curiosity. However, older adults' greater motivation to do well on cognitive tasks may leave them vulnerable to stereotype threat, the phenomenon by which individuals underperform when they are put in a position to either confirm or deny a negative stereotype about their group. In this opinion piece, we argue that most cognitive experiments, not just those designed to measure stereotype threat, likely induce some form of performance-related anxiety in older adults. This anxiety likely leads to greater task-related interference, or thoughts about how one is doing on the task, resulting in poorer performance. We discuss some of the potential implications for our understanding of neurocognitive aging.

Quality of Movement Is Associated With Cognitive Function in Physically Inactive Older Women

The relationship between the quality of movement, considering different global and universal basic patterns of movement and cognition domains in older adults remain unclear. The current study explored this association in physically inactive older women. In total, 187 participants, aged 60-70 years (mean = 64.9, SD = 6.9 years), were recruited from a physical education program in a public university. The older adults performed the following tests: Functional Movement Screen, Montreal Cognitive Assessment, and Modified Baecke Questionnaire for the Older Adults. The regression analysis showed an association between age (β = -0.11, 95% confidence interval, CI, [-0.10, 0.30], p = .03); visuospatial abilities (β = 0.36, 95% CI [0.24, 1.23], p < .001); language (β = 0.23, 95% CI [0.20, 1.08], p < .001); and orientation domains (β = 0.13, 95% CI [0.11, 1.22], p = .016) of the Montreal Cognitive Assessment and the Functional Movement Screen. The quality of movement was related to both age and cognitive performance, such as the visuospatial abilities, language, and orientation domains, in physically inactive older women.

Cortical Networks Underpinning Compensation of Verbal Fluency in Normal Aging

Elucidating compensatory mechanisms underpinning phonemic fluency (PF) may help to minimize its decline due to normal aging or neurodegenerative diseases. We investigated cortical brain networks potentially underpinning compensation of age-related differences in PF. Using graph theory, we constructed networks from measures of thickness for PF, semantic, and executive–visuospatial cortical networks. A total of 267 cognitively healthy individuals were divided into younger age (YA, 38–58 years) and older age (OA, 59–79 years) groups with low performance (LP) and high performance (HP) in PF: YA-LP, YA-HP, OA-LP, OA-HP. We found that the same pattern of reduced efficiency and increased transitivity was associated with both HP (compensation) and OA (aberrant network organization) in the PF and semantic cortical networks. When compared with the OA-LP group, the higher PF performance in the OA-HP group was associated with more segregated PF and semantic cortical networks, greater participation of frontal nodes, and stronger correlations within the PF cortical network. We conclude that more segregated cortical networks with strong involvement of frontal nodes seemed to allow older adults to maintain their high PF performance. Nodal analyses and measures of strength were helpful to disentangle compensation from the aberrant network organization associated with OA.

Age-Related Differences in Affective Norms for Chinese Words (AANC)

Information on age-related differences in affective meanings of words is widely used by researchers to study emotions, word recognition, attention, memory, and text-based sentiment analysis. To date, no Chinese affective norms for older adults are available although Chinese as a spoken language has the largest population in the world. This article presents the first large-scale age-related affective norms for 2,061 four-character Chinese words (AANC). Each word in this database has rating values in the four dimensions, namely, valence, arousal, dominance, and familiarity. We found that older adults tended to perceive positive words as more arousing and less controllable and evaluate negative words as less arousing and more controllable than younger adults did. This indicates that the positivity effect is reliable for older adults who show a processing bias toward positive vs. negative words. Our AANC database supplies valuable information for researchers to study how emotional characteristics of words influence the cognitive processes and how this influence evolves with age. This age-related difference study on affective norms not only provides a tool for cognitive science, gerontology, and psychology in experimental studies but also serves as a valuable resource for affective analysis in various natural language processing applications.

Reduced listener-speaker neural coupling underlies speech understanding difficulty in older adults

An increasing number of studies have highlighted the importance of listener-speaker neural coupling in successful verbal communication. Whether the brain-to-brain coupling changes with healthy aging and the possible role of this change in the speech comprehension of older adults remain unexplored. In this study, we scanned with fMRI a young and an older speaker telling real-life stories and then played the audio recordings to a group of young (N = 28, aged 19-27 year) and a group of older adults during scanning (N = 27, aged 53-75 year), respectively. The older listeners understood the speech less well than did the young listeners, and the age of the older listeners was negatively correlated with their level of speech understanding. Compared to the young listener-speaker dyads, the older dyads exhibited reduced neural couplings in both linguistic and extra-linguistic areas. Moreover, within the older group, the listener's age was negatively correlated with the overall strength of interbrain coupling, which in turn was associated with reduced speech understanding. These results reveal the deficits of older adults in achieving neural alignment with other brains, which may underlie the age-related decline in speech understanding.

Neuropsychological profile in the preclinical stages of dementia: principal component analysis approach

The preclinical stages of dementia include subtle neurocognitive changes that are not easily detected in standard clinical evaluations. Neuropsychological evaluation is important for the classification and prediction of deterioration in all the phases of dementia.

The Role of Processing Speed and Cognitive Control on Word Retrieval in Aging and Aphasia

Purpose When speakers retrieve words, they do so extremely quickly and accurately-both speed and accuracy of word retrieval are compromised in persons with aphasia (PWA). This study examined the contribution of two domain-general mechanisms: processing speed and cognitive control on word retrieval in PWA. Method Three groups of participants, neurologically healthy young and older adults and PWA (n = 15 in each group), performed processing speed, cognitive control, lexical decision, and word retrieval tasks on a computer. The relationship between word retrieval speed and other tasks was examined for each group. Results Both aging and aphasia resulted in slower processing speed but did not affect cognitive control. Word retrieval response time delays in PWA were eliminated when processing speed was accounted for. Word retrieval speed was predicted by individual differences in cognitive control in young and older adults and additionally by processing speed in older adults. In PWA, word retrieval speed was predicted by severity of language deficit and cognitive control. Conclusions This study shows that processing speed is compromised in aphasia and could account for their slowed response times. Individual differences in cognitive control predicted word retrieval speed in healthy adults and PWA. These findings highlight the need to include nonlinguistic cognitive mechanisms in future models of word retrieval in healthy adults and word retrieval deficits in aphasia.

Age-related effects on the neural processing of semantic complexity in a continuous narrative: Modulation by gestures already present in young to middle-aged adults

The processing of semantically complex speech is a demanding task which can be facilitated by speech-associated arm and hand gestures. However, the role of age concerning the perception of semantic complexity and the influence of gestures in this context remains unclear. The goal of this study was to investigate if age-related differences are already present in early adulthood during the processing of semantic complexity and gestures. To this end, we analyzed fMRI images of a sample of 38 young and middle-aged participants (age-range: 19-55). They had the task to listen and to watch a narrative. The narrative contained segments varying in the degree of semantic complexity, and they were spontaneously accompanied by gestures. The semantic complexity of the story was measured by the idea density. Consistent with previous findings in young adults, we observed increased activation for passages with lower compared to higher complexity in bilateral temporal areas and the precuneus. BOLD signal in the left frontal and left parietal regions correlated during the perception of complex passages with increasing age. This correlation was reduced for passages presented with gestures. Median-split based post-hoc comparisons confirmed that group differences between younger (19-23 years) and older adults within the early adult lifespan (24-55 years) were significantly reduced in passages with gestures. Our results suggest that older adults within early adulthood adapt to the requirements of highly complex passages activating additional regions when no gesture information is available. Gestures might play a facilitative role with increasing age, especially when speech is complex.

Age-related dissociation of N400 effect and lexical priming

The use of contextual information is an important capability to facilitate language comprehension. This can be shown by studying behavioral and neurophysiological measures of accelerated word recognition when semantically or phonemically related information is provided in advance, resulting in accompanying attenuation of the respective event-related potential, i.e. the N400 effect. Against the background of age-dependent changes in a broad variety of lexical capacities, we aimed to study whether word priming is accomplished differently in elderly compared to young persons. 19 young (29.9 ± 5.6 years) and 15 older (69.0 ± 7.2 years) healthy adults participated in a primed lexical decision task that required the classification of target stimuli (words or pseudo-words) following related or unrelated prime words. We assessed reaction time, task accuracy and N400 responses. Acceleration of word recognition by semantic and phonemic priming was significant in both groups, but resulted in overall larger priming effects in the older participants. Compared with young adults, the older participants were slower and less accurate in responding to unrelated word-pairs. The expected N400 effect was smaller in older than young adults, particularly during phonemic word and pseudo-word priming, with a rather similar N400 amplitude reduction by semantic relatedness. The observed pattern of results is consistent with preserved or even enhanced lexical context sensitivity in older compared to young adults. This, however, appears to involve compensatory cognitive strategies with higher lexical processing costs during phonological processing in particular, suggested by a reduced N400 effect in the elderly.

Cognitive reserve and network efficiency as compensatory mechanisms of the effect of aging on phonemic fluency

Compensation in cognitive aging is a topic of recent interest. However, factors contributing to cognitive compensation in functions such as phonemic fluency (PF) are not completely understood. Using cross-sectional data, we investigated cognitive reserve (CR) and network efficiency in young (32-58 years) versus old (59-84 years) individuals with high versus low performance in PF. ANCOVA was used to investigate the interaction between CR, age, and performance in PF. Random forest and graph theory analyses were conducted to study the contribution of cognition to PF and efficiency measures, respectively. Higher CR increased performance in PF and reduced age-related differences in PF. A slightly higher number of cognitive functions contributed to performance in high CR groups. The networks were more integrated in high CR individuals, both in the older age and high-performance groups. The strength and segregation of the networks were decreased in high-performance groups with high CR. We conclude that PF decreases less with age in individuals with higher CR, possibly due to a greater capacity to recruit non-linguistic cognitive networks, and efficient use of language networks, thereby integrating information in a rapid way across less fragmented networks. High CR and network efficiency seem to be important factors for cognitive compensation.

Electrophysiological differences in older and younger adults' anaphoric but not cataphoric pronoun processing in the absence of age-related behavioural slowdown

This study reports on an event-related potentials experiment to uncover whether per-millisecond electrophysiological brain activity and analogous behavioural responses are age-sensitive when comprehending anaphoric (referent-first) and cataphoric (pronoun-first) pronouns. Two groups of French speakers were recruited (young n = 18; aged 19-35 and older adults n = 15; aged 57-88) to read sentences where the anaphoric/cataphoric pronouns and their potential referents either matched or mismatched in gender. Our findings indicate that (1) the older adults were not less accurate or slower in their behavioural responses to the mismatches than the younger adults, (2) both anaphoric and cataphoric conditions evoked a central/parietally distributed P600 component with similar timing and amplitude in both the groups. Importantly, mean amplitudes of the P600 effect were modulated by verbal short-term memory span in the older adults but not in the younger adults, (3) nevertheless, the older but not the younger adults displayed an additional anterior negativity emerging on the frontal regions in response to the anaphoric mismatches. These results suggest that pronoun processing is resilient in healthy ageing individuals, but that functional recruitment of additional brain regions, evidenced with the anterior negativity, compensates for increased processing demands in the older adults' anaphora processing.

Functional Connectivity of Successful Picture-Naming: Age-Specific Organization and the Effect of Engaging in Stimulating Activities

Aging is a lifelong process that starts at birth. Throughout the course of their life, individuals are exposed to various levels of stimulating activities. A higher level of engagement in such activities is suspected to protect against the normal course of cognitive aging or the cognitive manifestations of age-related brain diseases. However, the exact mechanism underlying such protective action remains unclear. The concept of the neurocognitive reserve was introduced to refer to the hypothesis that engagement in stimulating activities shapes brain structure and function, thus indirectly allowing for better preserved cognitive abilities. Although it is known that word production is among the best-preserved cognitive abilities in aging, the underlying neurofunctional mechanisms that allow this relative preservation are still unknown, and it is still unclear how engagement in stimulating activities affects these processes. The objective of this study is to describe the brain functional connectivity patterns associated with picture-naming abilities in younger and older adults with varying levels of engagement in stimulating activities, as a proxy for neurocognitive reserve. A mediation analysis was applied to determine whether the association between reserve proxies and naming accuracy is dependent on task FC. Results show that naming accuracy depends on the posterior cingulate cortex (PCC) functional decoupling in both younger and older adults but through different pathways. While high-performing older adults rely on the asynchronization of this area from motor speech regions’ activity, the best-performing younger adults rely on the functional decoupling with language-related regions. Mediation analysis reveals that the PCC decoupling mediates the relationship between the level of engagement in stimulating activities and naming accuracy in younger adults, but not in older adults. These findings suggest that reserve-related mechanisms may be more critical for naming in early adult life, while older adults’ neurofunctional organization may benefit more from a lifetime of acquired knowledge.

Linear and Nonlinear Age Trajectories of Language Use: A Laboratory Observation Study of Couples' Conflict Conversations

OBJECTIVES

This study investigated linear and nonlinear age effects on language use with speech samples that were representative of naturally occurring conversations.

METHOD

Using a corpus-based approach, we examined couples' conflict conversations in the laboratory. The conversations, from a total of 364 community-dwelling German-speaking heterosexual couples (aged 19-82), were videotaped and transcribed. We examined usage of lower-frequency words, grammatical complexity, and utterance of filled pauses (e.g., äh ["um"]).

RESULTS

Multilevel models showed that age effects on the usage of lower-frequency words were nonsignificant. Grammatical complexity increased until middle age (i.e., 54) and then declined. The utterance of filled pauses increased until old age (i.e., 70) and then decreased.

DISCUSSION

Results are discussed in relation to cognitive aging research.

Increased functional connectivity supports language performance in healthy aging despite gray matter loss

Although language is quite preserved from aging, it remains unclear whether age-related differences lead to a deterioration or reorganization in language functional networks, or to different dynamics with other domains (e.g., the multiple-demand system). The present study is aimed at examining language networks, using resting-state functional magnetic resonance imaging in typical aging in relation to language performance. Twenty-three (23) younger adults and 24 healthy older adults were recruited. Volumetric gray matter differences between the 2 groups were assessed using voxel-based morphometry. Then, seed-based analyses, integrated local correlations in core regions of the language network, and within- and between-network connectivity were performed. We expected less extended connectivity maps, local coherence diminution, and higher connectivity with the multiple-demand system in older adults. On the contrary, analyses showed language network differences in healthy aging (i.e., increased connectivity with areas inside and outside language network), but no deterioration, despite widespread atrophy in older adults. Integrated local correlation revealed alterations that were unnoticeable with other analyses. Although gray matter loss was not correlated with language performance, connectivity differences were positively correlated with fluency performance in the older group. These results differ from the literature concerning other cognitive networks in aging in that they show extra internetwork connections without a decrease in intranetwork language connections. This reorganization could explain older adults' good language performance and could be interpreted in accordance with the scaffolding theory of aging and cognition.

Effect of Age in Auditory Go/No-Go Tasks: A Magnetoencephalographic Study

Response inhibition is frequently examined using visual go/no-go tasks. Recently, the auditory go/no-go paradigm has been also applied to several clinical and aging populations. However, age-related changes in the neural underpinnings of auditory go/no-go tasks are yet to be elucidated. We used magnetoencephalography combined with distributed source imaging methods to examine age-associated changes in neural responses to auditory no-go stimuli. Additionally, we compared the performance of high- and low-performing older adults to explore differences in cortical activation. Behavioral performance in terms of response inhibition was similar in younger and older adult groups. Relative to the younger adults, the older adults exhibited reduced cortical activation in the superior and middle temporal gyrus. However, we did not find any significant differences in cortical activation between the high- and low-performing older adults. Our results therefore support the hypothesis that inhibition is reduced during aging. The variation in cognitive performance among older adults confirms the need for further study on the underlying mechanisms of inhibition.

The Impact of the BAILAMOS™ Dance Program on Brain Functional Connectivity and Cognition in Older Latino Adults: A Pilot Study

Dance is a culturally salient form of physical activity (PA) for older Latinos. Resting-state functional connectivity (FC) is a putative biomarker for age-related cognitive decline. We aimed to investigate the impact of the BAILAMOS™ dance program on FC in three brain functional networks (Default Mode [DMN], Frontoparietal [FPN], and Salience [SAL] networks), and cognition. Ten cognitively healthy older Latinos participated in the four-month BAILAMOS™ dance program. We assessed PA levels (self-reported and device-assessed) and estimated cardiorespiratory fitness, cognition, and resting-state FC via functional magnetic resonance imaging at baseline and post-intervention. We performed paired t-tests and Pearson correlations. Given the pilot nature of the study, significance levels were set at p < 0.05 and effect sizes are reported. We observed a significant increase in self-reported moderate leisure-time PA from pre- to post-intervention (t(9) = 3.16, p = 0.011, d = 0.66). FC within-FPN regions of interest (ROIs) significantly increased pre- to post-intervention (t(9) = 2.35, p = 0.043, d = 0.70). DMN ROIs showed an increase, with a moderate effect size, in the integration with other networks' ROIs (t(9) = 1.96, p = 0.081, d = 0.64) post-intervention. Increases in moderate leisure-time PA at post-intervention were associated with increases in the FC within-FPN (R = 0.79, p = 0.006). Our results suggest that dance might be a promising approach for improving age-related disruption of FC within- and between-networks commonly associated with cognitive decline.

Cognitive compensatory mechanisms in normal aging: a study on verbal fluency and the contribution of other cognitive functions

Verbal fluency has been widely studied in cognitive aging. However, compensatory mechanisms that maintain its optimal performance with increasing age are not completely understood. Using cross-sectional data, we investigated differentiation and dedifferentiation processes in verbal fluency across the lifespan by analyzing the association between verbal fluency and numerous cognitive measures within four age groups (N=446): early middle-age (32-45 years), late middle-age (46-58 years), early elderly (59-71 years), and late elderly (72-84 years). ANCOVA was used to investigate the interaction between age and fluency modality. Random forest models were conducted to study the contribution of cognition to semantic, phonemic, and action fluency. All modalities declined with increasing age, but semantic fluency was the most vulnerable to aging. The most prominent reduction in performance was observed during the transition from middle-age to early elderly, when cognitive variables stopped contributing (differentiation), and new cognitive variables started contributing (dedifferentiation). Lexical access, processing speed, and executive functions were among the most contributing functions. We conclude that the association between age and verbal fluency is masked by age-specific influences of other cognitive functions. Differentiation and dedifferentiation processes can coexist. This study provides important data for better understanding of cognitive aging and compensatory processes.

Reduced right-hemisphere ERP P600 grammaticality effect is associated with greater right-hemisphere inhibition: Evidence from right-handers with familial sinistrality

The present study examined the hypothesis that left hemisphere (LH) equivalent language capabilities in the right hemisphere (RH) are inhibited in neurologically intact individuals by testing healthy young right-handers with a history of familial sinistrality (FS+, i.e. with at least one left handed biological relative), a population documented to show greater variability for RH language processing. Event-Related Potential (ERP) and split visual field presentation techniques were combined to assess LH- and RH- biased responses to syntactic category violations. In addition, a bilateral flanker task was used to measure inter-hemispheric inhibition ability in the same set of participants. Replicating prior findings, in addition to the LH-biased P600 grammaticality effect previously seen for right-handers in general, a fair amount, though not all, of FS + right-handers showed RH-biased P600 responses, leading to a reliable RH P600 grammaticality effect at the group level. Capitalizing on the variability of RH P600 responses, our results further revealed that reduced RH-biased P600 effects were reliably correlated with more effective RH inhibition (indexed by smaller reaction time differences between incongruent and neutral flankers presented to the RH via the left visual field). These results corroborated previous findings that the RH is capable of processing syntactic information in a manner qualitatively similar to that in the LH and further demonstrated that LH-equivalent processing in the RH as indexed by the P600 responses is modulated by RH inhibition, contributing to inter-individual variability in syntactic lateralization.

Stronger right hemisphere functional connectivity supports executive aspects of language in older adults

Healthy older adults commonly report increased difficulties with language production. This could reflect decline in the language network, or age-related declines in other cognitive abilities that support language production, such as executive function. To examine this possibility, we conducted a whole-brain resting-state functional connectivity (RSFC) analysis in older and younger adults using two seed regions-the left posterior superior temporal gyrus and left inferior frontal gyrus. Whole-brain connectivities were then correlated with Stroop task performance to investigate the relationship between RSFC and executive function. We found that overall, younger adults had stronger RSFC than older adults. Moreover, in older, but not younger, adults stronger RSFC between left IFG and right hemisphere executive function regions correlated with better Stroop performance. This suggests that stronger RSFC among older adults between left IFG and right hemisphere regions may serve a compensatory function.

The link between language and action in aging

OBJECTIVE

Many studies have demonstrated the existence of a link between action verb processing and action. However, little is known about the changes in this relationship with aging.

METHOD

To assess this point, we compare the performances of younger and older people during a priming task consisting of judging whether an image contains a human after listening to an action verb.

RESULTS

In accordance with previous literature, the results showed that younger people were faster to detect the presence of a human in the image in congruent conditions, namely, when the action verb and the image refer to the same action. However, this effect was not present in older adults' participants.

CONCLUSION

These findings suggest that the link between action and language decreases with age. We discuss these findings in the context of the embodied view of cognition.

The oscillatory mechanisms associated with syntactic binding in healthy ageing

Older adults frequently display differential patterns of brain activity compared to young adults in the same task, alongside widespread neuroanatomical changes. Differing functional activity patterns in older adults are commonly interpreted as being compensatory (e.g., Cabeza et al., 2002). We examined the oscillatory activity in the EEG during syntactic binding in young and older adults, as well as the relationship between oscillatory activity and behavioural performance on a syntactic judgement task within the older adults. 19 young and 41 older adults listened to two-word sentences that differentially load onto morpho-syntactic binding: correct syntactic binding (morpho-syntactically correct, e.g., "I dotch"); incorrect syntactic binding (morpho-syntactic agreement violation, e.g., "they dotches") and no syntactic binding (minimizing morpho-syntactic binding, e.g., "dotches spuff"). Behavioural performance, assessed in a syntactic judgement task, was characterized by inter-individual variability especially in older adults, with accuracy ranging from 76 to 100% in young adults and 58-100% in older adults. Compared to young adults, older adults were slower, but not less accurate. Functional neural signatures for syntactic binding were assessed as the difference in oscillatory power between the correct and no syntactic binding condition. In older adults, syntactic binding was associated with a smaller increase in theta (4-7 Hz), alpha (8-12 Hz) and beta (15-20 Hz) power in a time window surrounding the second word. There was a significant difference between the older and young adults: in the alpha range, the condition difference seemed to be in the opposite direction for older versus young adults. Our findings thus suggest that the neural signature associated with syntactic binding in older adults is different from young adults. However, we found no evidence of a significant association between behavioural performance and the neural signatures of syntactic binding for older adults, which does not readily support the predictions of compensatory models of language and ageing.

Waves of Maturation and Senescence in Micro-structural MRI Markers of Human Cortical Myelination over the Lifespan

Seminal human brain histology work has demonstrated developmental waves of myelination. Here, using a micro-structural magnetic resonance imaging (MRI) marker linked to myelin, we studied fine-grained age differences to deduce waves of growth, stability, and decline of cortical myelination over the life-cycle. In 484 participants, aged 8–85 years, we fitted smooth growth curves to T1- to T2-weighted ratio in each of 360 regions from one of seven cytoarchitectonic classes. From the first derivatives of these generally inverted-U trajectories, we defined three milestones: the age at peak growth; the age at onset of a stable plateau; and the age at the onset of decline. Age at peak growth had a bimodal distribution comprising an early (pre-pubertal) wave of primary sensory and motor cortices and a later (post-pubertal) wave of association, insular and limbic cortices. Most regions reached stability in the 30-s but there was a second wave reaching stability in the 50-s. Age at onset of decline was also bimodal: in some right hemisphere regions, the curve declined from the 60-s, but in other left hemisphere regions, there was no significant decline from the stable plateau. These results are consistent with regionally heterogeneous waves of intracortical myelinogenesis and age-related demyelination.

Tumor grade-related language and control network reorganization in patients with left cerebral glioma

Language processing relies on both a functionally specialized language network and a domain-general cognitive control network. Yet, how the two networks reorganize after damage resulting from diffuse and progressive glioma remains largely unknown. To address this issue, 130 patients with left cerebral gliomas, including 77 patients with low-grade glioma (LGG, WHO grade Ⅰ/II), 53 patients with high-grade glioma (HGG, WHO grade III/IV) and 38 healthy controls (HC) were adopted. The changes in resting-state functional connectivity (rsFC) of the language network and the cingulo-opercular/fronto-parietal (CO-FP) network were examined using network-based statistics. We found that tumor grade negatively correlated with language scores and language network integrity. Compared with HCs, patients with LGGs exhibited slight language deficits, both decreased and increased changes in rsFC of language network, and nearly normal CO-FP network. Patients with HGGs had significantly lower language scores than those with LGG and exhibited more severe language and CO-FP network disruptions than HCs or patients with LGGs. Moreover, we found that in patients with HGGs, the decreased rsFCs of language network were positively correlated with language scores. Together, our findings suggest tumor grade-related network reorganization of both language and control networks underlie the different levels of language impairments observed in patients with gliomas.

Lexical frequency affects functional activation and accuracy in picture naming among older and younger adults

As individuals age, they experience increased difficulties producing speech, especially with infrequent words. Older adults report that word retrieval difficulties frequently occur and are highly frustrating. However, little is known about how age affects the neural basis of language production. Moreover, age-related increases in brain activation are often observed, yet there is disagreement about whether such increases represent a form of neural compensation or dedifferentiation. We used functional magnetic resonance imaging (fMRI) to determine if there are age-related differences in functional activation during picture naming and whether such differences are consistent with a compensatory, dedifferentiation, or hybrid account that factors in difficulty. Healthy younger and older adults performed a picture-naming task with stimuli that varied in lexical frequency-our proxy for difficulty. Both younger and older adults were sensitive to lexical frequency behaviorally and neurally. However, younger adults performed more accurately overall and engaged both language (bilateral insula and temporal pole) and cognitive control (bilateral superior frontal gyri and left cingulate) regions to a greater extent than older adults when processing lower frequency items. In both groups, poorer performance was associated with increases in functional activation consistent with dedifferentiation. Moreover, there were age-related differences in the strength of these correlations, with better performing younger adults modulating the bilateral insula and temporal pole and better performing older adults modulating bilateral frontal pole and precuneus. Overall, these findings highlight the influence of task difficulty on fMRI activation in older adults and suggest that as task difficulty increases, older and younger adults rely on different neural resources. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Aging Effects on Phonological and Semantic Priming in the Tip-of-the-Tongue: Evidence From a Two-Step Approach

The mechanism underlying the age difference in spoken word production remains controversial. We used a two-step approach proposed by Gollan and Brown (2006) to investigate the semantic and phonological retrieval deficits when tip-of-the-tongue occurs in young and older adults. Importantly, we controlled the inhibition ability in both older and young groups. In experiment 1 with a people pictures naming task, older adults produced more TOTs than young adults, and they suffered from phonological retrieval deficit rather than semantic retrieval deficit in speaking. In experiment 2 with a priming paradigm, participants were presented semantically related or phonologically related names before target pictures, which formed semantic or phonological priming conditions for lexical access. Compared with young adults, older adults showed a greater effect of phonological priming on decreasing TOTs occurrence. For semantic retrieval deficit, older adults exhibited a smaller phonological facilitation effect and a larger semantic interference effect than young adults. For phonological retrieval deficit, older adults presented a larger phonological facilitation effect in the first-name related priming condition than the first-syllable related priming condition, whereas young adults showed similar facilitation effects between the two phonological priming conditions. Our findings provide consistent evidence for the transmission deficit hypothesis, and highlight that aging affects bidirectional connections between semantic and phonological nodes in speech production.

The Relationship Between the Striatal Dopaminergic Neuronal and Cognitive Function With Aging

Both cognitive function and striatal dopamine function decline by normal aging. However, the relationship among these three factors remains unclear. The aim of this study was to elucidate the association among age-related changes in the striatal dopamine transporter (DAT) and cognitive function in healthy subjects. The 30 healthy volunteers were enrolled in this research, the age ranged from 41 to 82 (64.5 ± 11.5, mean ± SD). All subjects were scanned with both T1-weighted magnetic resonance imaging (MRI) and ¹²³I-FP-CIT single-photon emission computed tomography (SPECT) images. The Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) was used to evaluate cognitive function. Six spherical regions of interest (ROI) using 10 mm in diameter on the caudate nucleus, anterior putamen and posterior putamen were manually drawn on MRI image which was applied onto SPECT image. The relationship between striatal occipital ratio (SOR) values and WAIS-III subscore were analyzed by multiple regression analysis. Subscores which was significant were further analyzed by path analyses. Full intelligence quotient (IQ), verbal IQ, verbal comprehension were all positively correlated with age-adjusted striatal DAT binding (P < 0.01). Multiple regression analyses revealed that the coding digit symbol correlated with all striatal regions except for the left caudate (P < 0.04). Picture completion and right caudate, similarities and left caudate also showed a positive correlation (P < 0.04). Path analysis found that the right caudate and picture completion; the left caudate and similarities were correlated independently from age, whereas the models of coding digit symbol were not significant. These results suggest that age-based individual diversity of striatal DAT binding was associated with verbal function, and the caudate nucleus plays an important role in this association.

fMRI reveals language-specific predictive coding during naturalistic sentence comprehension

Much research in cognitive neuroscience supports prediction as a canonical computation of cognition across domains. Is such predictive coding implemented by feedback from higher-order domain-general circuits, or is it locally implemented in domain-specific circuits? What information sources are used to generate these predictions? This study addresses these two questions in the context of language processing. We present fMRI evidence from a naturalistic comprehension paradigm (1) that predictive coding in the brain's response to language is domain-specific, and (2) that these predictions are sensitive both to local word co-occurrence patterns and to hierarchical structure. Using a recently developed continuous-time deconvolutional regression technique that supports data-driven hemodynamic response function discovery from continuous BOLD signal fluctuations in response to naturalistic stimuli, we found effects of prediction measures in the language network but not in the domain-general multiple-demand network, which supports executive control processes and has been previously implicated in language comprehension. Moreover, within the language network, surface-level and structural prediction effects were separable. The predictability effects in the language network were substantial, with the model capturing over 37% of explainable variance on held-out data. These findings indicate that human sentence processing mechanisms generate predictions about upcoming words using cognitive processes that are sensitive to hierarchical structure and specialized for language processing, rather than via feedback from high-level executive control mechanisms.

Aging-related differences in the cortical network subserving intelligible speech

Language communication is crucial throughout the lifespan. The current study investigated how aging affects the brain network subserving intelligible speech. Using functional magnetic resonance imaging, we compared brain responses to intelligible and unintelligible speech between older and young adults. Univariate and multivariate analyses revealed reduced brain activation and lower regional pattern distinctions in response to intelligible versus unintelligible speech in the left anterior superior temporal gyrus (aSTG) and the left inferior frontal gyrus (IFG) in the older compared with young adults. Notably, the functional connectivity between the left IFG and the left angular gyrus (AG) was increased and a significantly enhanced bidirectional effective connectivity between the left aSTG and the left AG was observed in the older adults for processing speech intelligibility. Our study revealed aging-related differences in the cortical activity for intelligible speech and suggested that increased frontal-temporal-parietal functional integration may help facilitate spoken language processing in older adults.

Age-Related Differences in Auditory Cortex Activity During Spoken Word Recognition

Understanding spoken words requires the rapid matching of a complex acoustic stimulus with stored lexical representations. The degree to which brain networks supporting spoken word recognition are affected by adult aging remains poorly understood. In the current study we used fMRI to measure the brain responses to spoken words in two conditions: an attentive listening condition, in which no response was required, and a repetition task. Listeners were 29 young adults (aged 19-30 years) and 32 older adults (aged 65-81 years) without self-reported hearing difficulty. We found largely similar patterns of activity during word perception for both young and older adults, centered on the bilateral superior temporal gyrus. As expected, the repetition condition resulted in significantly more activity in areas related to motor planning and execution (including the premotor cortex and supplemental motor area) compared to the attentive listening condition. Importantly, however, older adults showed significantly less activity in probabilistically defined auditory cortex than young adults when listening to individual words in both the attentive listening and repetition tasks. Age differences in auditory cortex activity were seen selectively for words (no age differences were present for 1-channel vocoded speech, used as a control condition), and could not be easily explained by accuracy on the task, movement in the scanner, or hearing sensitivity (available on a subset of participants). These findings indicate largely similar patterns of brain activity for young and older adults when listening to words in quiet, but suggest less recruitment of auditory cortex by the older adults.

The Effect of Distance on Sentence Processing by Older Adults

In sentences with long-distance dependency relations (“The man whom the police arrested is thin”), there are two kinds of distance between the gap (object position of arrested) and the filler man: linear (the intervening words in linear order), and structural (the intervening nodes in the syntactic tree). Previous studies found that older adults have difficulty comprehending sentences with long-distance dependency relations. However, it is not clear whether they are more disrupted by longer structural distance between gaps and fillers, or longer linear distance. There is a distinction between linear distance and structural distance, in that the former is directly related to working memory whereas the latter is associated with syntactic ability. By examining the effect of linear distance and structural distance on sentence processing by older adults, we can identify whether age-related decline in sentence comprehension is attributed to working memory dysfunction or syntactic decline. For this purpose, structural distance and linear distance were manipulated in Mandarin relative clauses (RCs). 30 older adults and 33 younger adults were instructed to perform a self-paced reading task. We found that both groups performed more slowly as structural distance increased, and less accurately when linear distance increased. More importantly, there was a significant interaction between linear distance and age group in the accuracy of comprehension, with linear distance disrupting older adults more than younger adults in offline processing. The findings suggest that the age-related decline in offline sentence comprehension might be attributable to the decline in working memory, rather than syntactic ability. Practical implications, limitations, and directions for future studies are discussed.

Prevalence of aphasia after stroke in a hospital population in southern Brazil: a retrospective cohort study

Background: Aphasia negatively impacts quality of life. This is the first Brazilian study that investigates the prevalence of aphasia and its related factors, the results of which may underpin hospital and health service planning for this vulnerable population.Objective: To establish the prevalence of aphasia in patients after first-ever ischemic stroke (FEIS) and associated factors.Methods: This is a retrospective cohort study, based on a database held in Joinville, Brazil. All cases of FEIS admitted to one public hospital in Joinville in 2015 were selected. The diagnosis of aphasia was verified by neurologists through the language item of the National Institute of Health Stroke Scale (NIHSS).Results: Of the 350 patients with FEIS, 79 (22.6%) had aphasia. Patients with aphasia (PWA) were older, with a higher likelihood of dysarthria, more thrombolytic use, and greater stroke severity. PWA had higher mortality than patients without aphasia (24.1% versus 10.7%, p = .004) and longer hospitalization time (21.32 versus 17.46 days, p = .009). Higher NIHSS score was an independent predictor for the occurrence of aphasia on admission (OR 1.24, 95% CI 1.17-1.31, p < .001). Older age (OR 1.06, 95% CI 1.03-1.09, p < .001) and stroke severity by NIHSS (OR 1.19, 95% CI 1.12-1.25, p = <0.001) were independent predictors of death.Conclusions: PWA may need more health care during hospitalization, because of the severity of the stroke, and their frailty. Further studies are needed to assess the direct impact of aphasia on inpatients.

Rastreio cognitivo em estruturas residenciais para pessoas idosas no Concelho de Miranda do Corvo, Portugal

Resumo Com o objetivo de efetuar o rastreio do perfil cognitivo dos residentes em Estruturas Para Idosos no Concelho de Miranda do Corvo, avaliaram-se 174 participantes recorrendo ao Mini-Mental State Examination (MMSE) (n=96) e ao diagnóstico de demência reportado nos prontuários dos pacientes (n=78). Verificou-se, através do MMSE, que 41,7% dos inquiridos apresentavam pontuações sugestivas de déficit cognitivo. Adicionando a este resultado o diagnóstico de demência reportado nos prontuários dos pacientes, a percentagem subiu para 67,8% (n=118). A comparação dos nossos resultados com os obtidos a nível nacional revelou que essa percentagem foi significativamente superior (p<0,001). A escolaridade foi um fator preditivo da pontuação do MMSE (p=0,001). Conclui-se que a elevada prevalência de suspeita de déficit cognitivo e de demência revelada no nosso estudo deve remeter para a reflexão sobre a adequação dos cuidados prestados e sobre a ausência/escassez de programas de estimulação cognitiva nas estruturas residenciais para idosos. Nesse sentido, torna-se imperativo implementar avaliação cognitiva regular e instituir programas de intervenção que promovam a conservação e melhoria do funcionamento cognitivo em pessoas idosas institucionalizadas de zonas desfavorecidas.

Testing the influence of musical expertise on novel word learning across the lifespan using a cross-sectional approach in children, young adults and older adults

Word learning is a multifaceted perceptual and cognitive task that is omnipresent in everyday life. Currently, it is unclear whether this ability is influenced by age, musical expertise or both variables. Accordingly, we used EEG and compared behavioral and electrophysiological indices of word learning between older adults with and without musical expertise (older adults' perspective) as well as between musically trained and untrained children, young adults, and older adults (lifespan perspective). Results of the older adults' perspective showed that the ability to learn new words is preserved in elderly, however, without a beneficial influence of musical expertise. Otherwise, results of the lifespan perspective revealed lower error rates and faster reaction times in young adults compared to children and older adults. Furthermore, musically trained children and young adults outperformed participants without musical expertise, and this advantage was accompanied by EEG manifestations reflecting faster learning and neural facilitation in accessing lexical-semantic representations.

Cognitive Diversity in a Healthy Aging Cohort: Cross-Domain Cognition in the Cam-CAN Project

Objective: Studies of "healthy" cognitive aging often focus on a limited set of measures that decline with age. The current study argues that defining and supporting healthy cognition requires understanding diverse cognitive performance across the lifespan. Method: Data from the Cambridge Centre for Aging and Neuroscience (Cam-CAN) cohort was examined across a range of cognitive domains. Performance was related to lifestyle including education, social engagement, and enrichment activities. Results: Results indicate variable relationships between cognition and age (positive, negative, or no relationship). Principal components analysis indicated maintained cognitive diversity across the adult lifespan, and that cognition-lifestyle relationships differed by age and domain. Discussion: Our findings support a view of normal cognitive aging as a lifelong developmental process with diverse relationships between cognition, lifestyle, and age. This reinforces the need for large-scale studies of cognitive aging to include a wider range of both ages and cognitive tasks.

Interregional causal influences of brain metabolic activity reveal the spread of aging effects during normal aging

During healthy brain aging, different brain regions show anatomical or functional declines at different rates, and some regions may show compensatory increases in functional activity. However, few studies have explored interregional influences of brain activity during the aging process. We proposed a causality analysis framework combining high dimensionality independent component analysis (ICA), Granger causality, and least absolute shrinkage and selection operator regression on longitudinal brain metabolic activity data measured by Fludeoxyglucose positron emission tomography (FDG-PET). We analyzed FDG-PET images from healthy old subjects, who were scanned for at least five sessions with an averaged intersession interval of 1 year. The longitudinal data were concatenated across subjects to form a time series, and the first-order autoregressive model was used to measure interregional causality among the independent sources of metabolic activity identified using ICA. Several independent sources with reduced metabolic activity in aging, including the anterior temporal lobe and orbital frontal cortex, demonstrated causal influences over many widespread brain regions. On the other hand, the influenced regions were more distributed, and had smaller age-related declines or even relatively increased metabolic activity. The current data demonstrated interregional spreads of aging on metabolic activity at the scale of a year, and have identified key brain regions in the aging process that have strong influences over other regions.