Purpose: Motivation and self-efficacy are established predictors of engagement and persistence within structured exercise programmes; however, it remains unclear whether these psychological factors predict objective adherence metrics and associated physical fitness outcomes within home-based exercise programmes for older adults. This study adopted a person-centred approach to examine whether distinct psychological profiles predict adherence and fitness outcomes following a structured home-based exercise programme. Methods: Eighty-eight older adults (age = 67.2 ± 5.5 years) completed a 26-week home-based exercise programme. Objective adherence was defined as compliance with prescribed exercise volume and quantified using cumulative metabolic equivalent minutes (MET-mins) derived from heart rate–based measures of exercise intensity and duration. Psychological profiles were identified using latent profile analysis based on autonomous motivation, controlled motivation, and exercise self-efficacy. Cardiorespiratory fitness, muscular strength, flexibility, and mobility were assessed pre- and post-intervention. Results: Two psychological profiles were identified: an autonomous and highly confident profile and a moderately autonomous and confident profile. Controlled motivation was comparable between profiles, and no differences were observed in baseline demographic or physiological characteristics. Adherence was high and similar across profiles (e.g., cumulative MET-mins: 129 ± 66% vs. 116 ± 38%). Both profiles demonstrated significant and comparable improvements in cardiorespiratory fitness (V̇O₂peak), muscular strength, flexibility, and mobility. Conclusions: Baseline differences in self-efficacy and autonomous motivation did not predict objective adherence or fitness outcomes within a structured, well-supported home-based exercise programme for older adults. Consistent objective monitoring and regular behavioural support may therefore reduce the impact of psychological profile membership on adherence and outcomes. Keywords: ageing; exercise adherence; home-based exercise; latent profile analysis; autonomous motivation; self-efficacy

Syntactic priming paradigms are widely used to investigate language production, yet they are almost exclusively implemented in controlled laboratory settings. This limits scalability, inclusivity, and the study of language behavior in everyday contexts. Here, we present and validate a smartphone-based method for measuring syntactic priming. Our mobile application implements a picture description task commonly used in laboratory studies and incorporates automated speech transcription and syntactic classification. Using our app, we collected data on the production of active and passive sentence structures and evaluated short-term, cumulative, and long-term (across sessions) priming effects. To assess methodological validity, we compared the patterns observed in app-collected data with those obtained previously using an equivalent laboratory paradigm. Results demonstrate that the mobile app reliably elicits short-term syntactic priming, with increased production of passive structures following passive primes, replicating well-established laboratory effects. Within-session analyses further revealed cumulative priming, indicating gradual learning of infrequent syntactic structures. Long-term priming over a one-week interval was not observed in the app data, in contrast to laboratory findings. However, a follow-up experiment with a 24-hour interval between sessions yielded significant long-term priming effects, suggesting that retention of syntactic learning may decay more rapidly in uncontrolled, real-world environments. Together, these findings establish the mobile application as a valid and scalable method for studying syntactic priming outside the laboratory. The approach enables large-scale data collection in naturalistic settings and provides a flexible methodological framework for investigating individual differences in large diverse samples, and potential intervention applications in language research.

We investigated whether the difference between chronological and modeled brain age explains individual differences in language performance among healthy older adults. Age-related decline in language abilities is widely documented, with considerable variability among healthy older individuals in both language performance and underlying neural substrate. We derived predicted brain age from grey and white matter using machine learning and used this measure to estimate neurological deviations from chronological age. Using Bayesian mixed-effects modeling, we tested whether brain-age deviations predict language performance in a sample of 86 adults aged 60 years and above. We assessed the effect of brain-age deviations on performance across four well-established language processing tasks, each tapping into linguistic domains known to be vulnerable to ageing and show individual variability in skill levels, in both comprehension and production. Our findings suggest that, in healthy older individuals, predicted deviations of brain age from chronological age do not predict language abilities. This challenges the idea that brain age is a reliable determinant of language processing variability, at least in healthy (as opposed to pathological) ageing and highlights the need to consider other neural and cognitive factors when studying language decline.

Cognitive decline associated with healthy ageing is multifactorial: brain-based and lifestyle factors uniquely and jointly contribute to distinct neurocognitive trajectories of ageing. To evaluate existing models of neurocognitive ageing such as compensation, maintenance, or reserve, we explore how various known brain-based and cardiorespiratory fitness factors intersect to better understand cognitive decline. In a pre-registered study (https://osf.io/6fqg7), we tested 73 healthy older adults aged 60-81 (M = 65.51, SD = 4.94) and collected neuroimaging (functional, structural, and perfusion MRI), cardiorespiratory fitness, and cognitive data to investigate a prominent challenge for older adults: word-finding failures. fMRI signal was recorded while participants responded to a definition-based tip-of-the-tongue task, T1-weighted imaging estimated grey matter volume, and cerebral blood flow was indexed using multi-delay pseudo-continuous arterial spin labelling. Commonality analyses were used to analyse these multi-domain data (neuroimaging, cardiorespiratory fitness, language skills, demographic characteristics) and uncover associations between predictors in explaining age-related tip-of-the-tongue rates. Commonality analyses revealed that functional activation of language networks associated with tip-of-the-tongue states is in part linked with age and, interestingly, cardiorespiratory fitness: the combination of higher cardiorespiratory fitness and functional recruitment in some older adults offsets part of the age-related variance in tip-of-the-tongues. Moreover, age-associated atrophy and perfusion in regions other than those showing functional differences accounted for variance in tip-of-the-tongues. Our findings can be interpreted in the context of the classic models of neurocognitive ageing, suggesting compensation. Brain health indices in concordance with cardiorespiratory fitness can provide a more holistic explanation of individual differences in age-related cognitive decline.

Purpose: The Lexical Quality Hypothesis (LQH) posits that differences in the precision of orthographic, semantic, and phonological word representations affect language processing. While LQH components are typically investigated in reading, their role in resolving cognitive conflict remains unknown. This study applies the construct of lexical precision to the traditional naming Stroop task, a gold-standard to quantify cognitive conflict resolution specifically investigating its influence in dyslexia and stuttering. Method: Stroop interference was measured in 84 neurotypical readers, 50 dyslexic adults and 30 adults who stutter (AWS). All participants completed a naming Stroop task, together with a suite of individual difference measures that were analysed using a Principal Component Analysis, which established measures of phonological precision and lexical precision. Results: The data showed that, on average, dyslexic adults and AWS showed significantly larger Stroop interference effects compared with neurotypical adults. Crucially, the magnitude of the Stroop interference was moderated by lexical precision. Dyslexic adults and AWS who scored higher on the lexical precision component showed Stroop interference levels similar to the neurotypical adults, while those with lower precision demonstrated a significantly larger Stroop interference. However, the level of Stroop interference did not differ between AWS and dyslexic adults. Conclusions: The results indicate that an imprecise lexical representation underpins the difficulties in cognitive control mechanisms that are independent of the specific neurodivergent groups.

To examine the combined effects of ageing and bilingualism in language processing, we tested young and older mono- and bilingual speakers in L1 comprehension and production. In Experiment 1, bilinguals were slower to detect words than monolinguals in sentences with a low-constraint context, but not when a high-constraint context was provided. Older adults tended to outperform younger adults in high-constraint sentences. In Experiment 2, older speakers were slower than younger speakers to produce small-scope prepositional phrases (e.g., 'the cone above the grape), suggesting more extensive planning. Bilingual disadvantages were observed in larger-scope complex phrases (e.g., 'the cone and the pink grape'). Individual differences in language proficiency did not modulate the effects. The results support bilingual disadvantages in syntactic processing and age-preserved syntax, alongside semantic processing unaffected by either bilingualism or age. We found no interactions between age and bilingualism, suggesting that these two factors independently impact language processing.

Exercise training has been proposed to counteract age-related cognitive decline through improvements in cardiorespiratory fitness (CRF hypothesis). Research has focused on cognitive domains such as attention and processing speed, and one cross-sectional study reported a positive relationship between CRF and language production. In a randomized controlled trial, we investigated whether these benefits could extend to language comprehension in healthy older adults, and whether bilinguals, for whom language processing is more costly, would exhibit greater benefits than monolinguals. 80 older English monolinguals and 80 older Norwegian-English bilinguals were randomized into either a 6-month exercise training group or to a passive control group. We assessed CRF (V̇O2peak) and language comprehension (reaction times to spoken word monitoring) in first (L1, all participants) and second language (L2, bilinguals only), before and after the exercise training intervention. We found that monolinguals in the exercise group (compared to the control group) were faster in comprehension following the intervention. Moreover, this effect was mediated by exercise-induced increases in V̇O2peak, supporting the CRF hypothesis. This extends previous cross-sectional research and establishes a causal link between exercise training and speeded comprehension in older monolinguals. However, exercise training did not affect bilingual (L1 or L2) comprehension, despite inducing increased V̇O2peak, and bilinguals in both groups were slower after the intervention period. Exploratory analyses suggested that this may be driven by participants with low L2 proficiency, but further research is needed to examine whether bilingual language processing is in fact unaffected by exercise training and its consequent improvements in CRF.

Both ageing and bilingualism can have positive as well as adverse cognitive effects. We investigated their combined impact on subcomponents of attention. We used the Attention Network Task to examine alerting, orienting, executive control and task-switching costs. Group comparisons revealed age-related declines for alerting alongside benefits for executive control, for mono- and bilinguals alike. For orienting, age-related decline was more pronounced for bilinguals than monolinguals. Task-switching was unaffected by age or language group. Within bilinguals, we found limited impact of individual differences in L2 proficiency, language switching or mixing: proficiency improves orienting and decreases switch costs, for young and older bilinguals alike; but no other individual differences effects were found. Thus, attention is a multi-faceted network, with clear adverse (alerting) and protective (executive control) ageing effects. We found these to be largely similar for mono- and bilinguals, with variability within bilinguals having only limited impact.

Many people experience some degree of decline in language processes as they grow older, limiting their ability to pursue their interests and reducing their quality of life. Evidence suggests that physical fitness and the ability to speak another language can help combat cognitive decline, a topic at the heart of Professor Linda Wheeldon and Dr. Katrien Segaert’s work in the FAB project.

Exercise training has been proposed to counteract age-related cognitive decline through improvements in cardiorespiratory fitness (CRF hypothesis). Research has focused on cognitive domains like attention and processing speed, and one cross-sectional study reported a positive relationship between CRF and language production in older adults. In a randomized controlled trial, we investigated whether these benefits could extend to language comprehension in healthy older adults, and whether bilinguals, for whom language processing is more costly, would exhibit greater benefits than monolinguals. Eighty older English monolinguals and 80 older Norwegian-English bilinguals were randomized into either a 6-month exercise training group or into a passive control group. We assessed CRF (VO2peak) and language comprehension (reaction times to spoken word monitoring) in first (L1, all participants) and second language (L2, bilinguals only), before and after the intervention. We found that monolinguals in the exercise group (compared to the control group) were faster in comprehension following the intervention. Moreover, this effect was mediated by exercise-induced increases in VO2peak, supporting the CRF hypothesis. This extends previous cross-sectional research and establishes a causal link between exercise training and speeded comprehension in older monolinguals. However, despite inducing increased VO2peak, exercise training did not affect bilingual (L1 or L2) comprehension, and bilinguals in both groups were slower after the intervention period. Exploratory analyses suggested that this slowing may be driven by participants with low L2 proficiency, but further research is needed to examine whether bilingual language processing is in fact unaffected by exercise training and its consequent improvements in CRF.

Cognitive decline associated with healthy ageing is complex and multifactorial: vascular and lifestyle factors uniquely and jointly contribute to distinct neurocognitive trajectories of ageing. To evaluate existing accounts of neurocognitive ageing that propose mechanisms of compensation, maintenance or reserve, studies should explore how various known brain-based and lifestyle factors intersect to better understand cognitive decline. Here, we bring together brain function, structure, perfusion, and cardiorespiratory fitness to investigate a well-documented, prominent cognitive challenge for older adults: word-finding failures. Commonality analysis on 73 neurologically healthy older adults revealed that functional activation of language networks associated with tip-of-the-tongue states is in part determined by age and, interestingly, cardiorespiratory fitness levels. Age-associated atrophy and perfusion in regions other than those showing functional differences accounted for variance in tip-of-the-tongue states. Our findings can be interpreted in the context of the classic models of neurocognitive ageing, with mechanisms of compensation and reserve interacting with each other.Highlights ### Competing Interest StatementThe authors have declared no competing interest.

Successful sentence comprehension requires the binding, or composition, of multiple words into larger structures to establish meaning. Using magnetoencephalography, we investigated the neural mechanisms involved in binding at the syntax level, in a task where contributions from semantics were minimized. Participants were auditorily presented with minimal sentences that required binding (pronoun and pseudo-verb with the corresponding morphological inflection; “ she grushes ”) and pseudo-verb wordlists that did not require binding (“ cugged grushes ”). Relative to no binding, we found that syntactic binding was associated with a modulation in alpha band (8-12 Hz) activity in left-lateralized language regions. First, we observed a significantly smaller increase in alpha power around the presentation of the target word (“ grushes ”) that required binding (-0.05s to 0.1s), which we suggest reflects an expectation of binding to occur. Second, during binding of the target word (0.15s to 0.25s), we observed significantly decreased alpha phase-locking between the left inferior frontal gyrus and the left middle/inferior temporal cortex, which we suggest reflects alpha-driven cortical disinhibition serving to strengthen communication within the syntax composition neural network. Together, our findings highlight the critical role of rapid spatial-temporal alpha band activity in controlling the allocation, transfer and coordination of the brain’s resources during syntax composition.

Perfetti (2007) proposed that the quality of lexical representations affects reading. We investigated the role of lexical quality in decoding. Eighty-four adults read aloud words and pseudowords with dense and sparse neighbourhoods in a masked form-priming experiment. Individual-difference measures of language and cognitive processes were collected and entered into a principal component analysis (PCA). Compared to a non-overlapping control prime, we observed greater facilitatory form-priming for word targets with sparse neighbourhoods than those with dense neighbourhoods. A PCA component related to orthographic precision affected form-priming: people with low orthographic precision showed greater facilitation for words with sparse neighbourhoods, primed by pseudowords, than those with dense neighbourhoods. People with high orthographic precision demonstrated the converse, only when primed by words. For pseudoword reading, word primes facilitated more than pseudoword primes in people with low orthographic precision. People with high orthographic precision showed the opposite pattern.

During the production of spoken sentences, the linearisation of a 'thought' is accomplished via the process of grammatical encoding, i.e., the building of a hierarchical syntactic frame that fixes the linear order of lexical concepts. While much research has demonstrated the independence of lexical and syntactic representations, exactly what is represented remains a matter of dispute. Moreover, theories differ in terms of whether words or syntax drive grammatical encoding. This debate is also central to theories of the time-course of grammatical encoding. Speaking is usually a rapid process in which articulation begins before an utterance has been entirely planned. Current theories of grammatical encoding make different claims about the scope of grammatical encoding prior to utterance onset, and the degree to which planning scope is determined by linguistic structure or by cognitive factors. The authors review current theories of grammatical encoding and evaluate them in light of relevant empirical evidence. This title is also available as Open Access on Cambridge Core.

Sentence reading involves constant competition between lexical candidates. Previous research with monolinguals has shown that the neighbours of a read word are inhibited, making their retrieval as a subsequent target more difficult, but the duration of this interference may depend on reading skills. In this study, we examined neighbour priming effects in sentence reading among proficient Norwegian–English bilinguals reading in their L2. We investigated the effects of the distance between prime and target (short vs. long) and the nature of the overlap between the two words (beginning or end), and related these to differences in individual cognitive skills. Our results replicated the inhibition effects found in monolinguals, albeit slightly delayed. Interference between form-related words was affected by the L2 reading skills and, crucially, by the phonological decoding abilities of the bilingual reader. We discuss the results in light of competition models of bilingual reading as well as episodic memory accounts.

We conducted an artificial language learning experiment to study learning asymmetries that might reveal latent preferences relating to, and any dependencies between, the edge alignment and quantity sensitivity (QS) parameters in stress patterning. We used a poverty of the stimulus approach to teach American English speakers an unbounded QS stress rule (stress a single CV: syllable) and either a left- or right-aligning QI rule if only light syllables were present. Forms with two CV: syllables were withheld in the learning phase and added in the test phase, forcing participants to choose between left- and right-aligning options for the QS rule. Participants learned the left- and right-edge QI rules equally well, and also the basic QS rule. Response patterns for words with two CV: syllables suggest biases favoring a left-aligning QS rule with a left-edge QI default. Our results also suggest that a left-aligning QS pattern with a rightedge QI default was least favored. We argue that stress patterns shown to be preferred based on evidence from ease-of-learning and participants’ untrained generalizations can be considered more natural than less favored opposing patterns. We suggest that cognitive biases revealed by artificial stress learning studies may have contributed to shaping stress typology.

Previous psycholinguistic research has indicated that, despite containing two or more lexical units, English compounds are treated as single prosodic units in connected speech. However, there exist many compound-like structures in English that resemble phrases, in that they exhibit inter-word spacing, e.g. ice cream or time zone . Using a naming task, we compared speech production latencies for responses containing visually concatenated compounds (e.g. teacups), spaced compound-like structures ( time zones), adjective-noun phrases (tame sharks), and monomorphemic words (targets, teams). We found that, despite being visually identical to phrases, spaced compound-like structures were treated as single prosodic items, similar to visually-concatenated compounds and monomorphemic disyllabic words. This not only lends support to the claim that compound words are treated as single prosodic units, but also that visual concatenation is not a reliable indicator of compounding in English.

Mild cognitive impairment (MCI) is the term used to identify those individuals with subjective and objective cognitive decline but with preserved activities of daily living and an absence of dementia. Although MCI can impact functioning in different cognitive domains, most notably episodic memory, relatively little is known about the comprehension of language in MCI. In this study, we used around-the-ear electrodes (cEEGrids) to identify impairments during language comprehension in patients with MCI. In a group of 23 patients with MCI and 23 age-matched controls, language comprehension was tested in a two-word phrase paradigm. We examined the oscillatory changes following word onset as a function of lexico-semantic single-word retrieval (e.g., swrfeq vs. swift) and multiword binding processes (e.g., horse preceded by swift vs. preceded by swrfeq). Electrophysiological signatures (as measured by the cEEGrids) were significantly different between patients with MCI and controls. In controls, lexical retrieval was associated with a rebound in the alpha/beta range, and binding was associated with a post-word alpha/beta suppression. In contrast, both the single-word retrieval and multiword binding signatures were absent in the MCI group. The signatures observed using cEEGrids in controls were comparable with those signatures obtained with a full-cap EEG setup. Importantly, our findings suggest that patients with MCI have impaired electrophysiological signatures for comprehending single words and multiword phrases. Moreover, cEEGrid setups provide a noninvasive and sensitive clinical tool for detecting early impairments in language comprehension in MCI.