Cognitive scientists have long debated the capabilities of non-conscious perception, defined as the level of processing of external stimuli that people do not consciously experience. While much is known about non-conscious visual perception, the auditory modality has received less focus. Here, we examine the level of processing for audible and intelligible spoken words that participants did not notice while performing another difficult visual task. Using repeated occurrences of such inattentional deafness and awareness probes, we measure the non-conscious processing of undetected words. In two pre-registered EEG experiments (N = 67), detected words elicited a frontal followed by a parietal scalp positivity, compared to matched pseudowords. Undetected words, however, showed frontal positivity compared to pseudowords, which differed in distribution and latency from the response to detected words. An exploratory analysis revealed a behavioral interference of undetected words with visual task performance. Both markers of non-conscious processing were contingent on relevance, implying that auditory non-conscious processing is automatic yet goal-dependent. Overall, our results support flexible capabilities for non-conscious speech perception, consistent with the ability to integrate acoustic information over time.

Discourse production, including the use of discourse particles, is crucial in everyday communication. Discourse particles (e.g., ja 'yeah') form a heterogeneous group of words that fulfil different functions such as structuring the discourse or marking the relationship between the hearer and speaker. Primary progressive aphasia (PPA) is a neurodegenerative language condition that causes communication breakdowns. In this study, we examined the production of discourse particles by 58 Dutch-speaking individuals with PPA and 40 neurologically healthy speakers (NHS). We analysed language samples obtained from a picture description task for the use of discourse particles, comprising both discourse particles that require an assessment of the interlocutor's discourse belief (e.g., eigenlijk 'actually') as well as discourse particles with a more general discourse-structuring function (e.g., ja 'yeah' nee 'no', nou 'well'). We found that individuals with PPA used the discourse particle ja 'yeah' more frequently than NHS (p < .001) relative to eigenlijk. The results also showed that the discourse particles nee 'no' and nou 'well' were used differently by individuals with PPA versus NHS. These discourse particles were employed by individuals with PPA to signal or manage word-finding difficulties. The findings underline the variety in functions and complexity of discourse markers. Studying and comparing the use of individual particles by speakers with a neurodegenerative language disorder is therefore not only informative to understand these disorders but also provides more insight into the heterogeneity of the class of discourse particles.

Beyond their predominant language impairments, primary progressive aphasias (PPA) are also marked by non-linguistic cognitive deficits. Among these, social cognition deficits have been understudied, particularly in the non-fluent (nfvPPA) and logopenic (lvPPA) variants. This review synthesizes behavioural and imaging data on emotion recognition, empathy, and theory of mind (ToM) in nfvPPA and lvPPA, and examines their potential contribution to the differential diagnosis. Evidence suggests that both variants exhibit social cognition deficits. Emotion recognition deficits are observed from disease onset in nfvPPA and lvPPA, although performance varies across modalities and tasks. Empathy appears relatively preserved in early stages, with cognitive aspects showing more variability than affective empathy. Theory of mind is consistently impaired in nfvPPA but remains largely unexplored in lvPPA. Limited comparative research and lack of ToM studies in lvPPA constrain our understanding of variant-specific profiles. However, combining emotion recognition with other cognitive measures shows potential to improve classification of these variants. Similarly, a more rapid decline in empathy in nfvPPA could contribute to differential diagnosis as the disease progresses. Finally, hypotheses based on anatomo-clinical correlates suggest distinct ToM deficits between variants. By highlighting variant-specific profiles and gaps in research, this review provides a comprehensive framework to guide future research, improve diagnostic accuracy and inform clinical management of these syndromes.

Previous EEG research has shown that observing others in pain increases sensorimotor activity, as indexed by Mu (7-12 Hz) and Beta (13-30 Hz) desynchronization. Such activity is often interpreted as reflecting empathic processing through shared neural representations between the observer and target. In everyday life, observing another in pain can trigger a range of potential action tendencies (e.g., withdrawing, helping, or protecting oneself), but EEG studies typically restrict movement to avoid artifacts. This immobility may produce an artificial scenario that limits our understanding of how motor readiness and empathic processing interact. The present study examined whether engaging the motor system (via a simple key press) modulates these neural responses. Participants observed videos and pictures of a hand being stabbed by a needle or touched by a Q-tip. In half of the blocks, they prepared and executed a speeded key press to a Go signal; in the other half, they remained still. Results revealed Mu and Beta desynchronization during pain observation regardless of movement condition, replicating prior findings. These effects were unrelated to reaction times or empathy traits, suggesting that sensorimotor resonance during pain observation reflects a stable response rather than one contingent on task-specific motor preparation.

Hair is a salient feature of the bodies of humans and other mammals, which serves a variety of functions, including sensation. The sensory functions of hairs in humans, however, remain poorly understood. This study measured the ability to perceive the spatial location of stimulation of hairs without associated stimulation of the skin. We tested this ability body on the hand (Experiment 1) and the forearm (Experiment 2). Participants judged locations by clicking on a picture of their own hand/arm. We compared tactile localisation performance following hair stimulation to direct stimulation of the skin. Participants showed highly precise localisation of hair stimulation. The precision of localisation of hair stimulation is similar to that of stimulation of the skin. The results of this study show that human hairs provide rich spatial information which may complement tactile signals from the skin itself.

I argue that cognitive neurorehabilitation is currently faced with important challenges for its progress. Whereas most challenges are already well-known and debated in the field, a relatively overlooked challenge is whether cognitive functions are multiply realized. I argue that this debate is central to progress in cognitive neurorehabilitation. I conclude arguing that progress is possible but requires methodological improvements to determine how and not just if a function is rehabilitated, and methods to decide whether two instances of a cognitive function are identical. The aim of this article is therefore twofold: first, to demonstrate why the question of multiple realization is not an abstract philosophical curiosity but a methodological bottleneck for research in cognitive neurorehabilitation, and-second - to suggest directions for empirical innovation that can help resolve whether observed recovery reflects restoration, compensation, or genuine multiple realization.

Long-term semantic systems are specialized for taxonomic and thematic relations. In the present study, we investigated the influence of taxonomic and thematic relations on object naming. Leveraging the existing dataset (N = 32) and expanding the sample (total N = 48). Using a blocked cyclic naming paradigm, we explored semantic effects within both taxonomic and thematic contexts, using an identical set of stimuli. A set of sixteen objects was categorized into either a taxonomic context or a thematic context. Our results show that both contexts trigger semantic interference, with a more pronounced interference in the taxonomic context than in the thematic context. The taxonomic context modulated event-related potentials (ERPs) within the time windows of 134-456 msec after picture onset, while the thematic context modulated ERPs in 230-362 msec after picture onset. These results reveal larger and earlier effects of taxonomic relations compared to thematic relations, indicating that taxonomic relation prevails in object naming.

Recent advances in neuroscience and artificial intelligence have pushed the state-of-the-art from being able to decode the meaning of individual words from non-invasive brain recordings, to the reconstruction of the meaning of continuous language. Beyond game changing practical implications of such "mind reading" mapping models, e.g., brain-computer interfaces that restore lost ability to speak, they also hold the promise to be instrumental in addressing a fundamental question in the cognitive sciences: How does the human brain represent the meaning of concepts, phrases, and sentences? In order to fulfil this promise, however, important methodological and theoretical challenges need to be overcome: (1) extant mapping results are inconsistent and difficult to reconcile with neurocognitive theory, (2) extant neural meaning representations do not model the compositional semantics capturing the meaning of multi-word utterances, and (3) extant mapping models fail to take into account the spatiotemporal dynamics of lexical and compositional semantic representation and computation. I argue that in order to overcome these challenges, we should ground mapping models in linguistic and neurocognitive theory, and develop neurocomputational models that explicate the spatiotemporal dynamics of meaning in the brain's language.

Children's ability to extract statistical regularities from speech is considered fundamental to lexical, syntactic, and grammatical development. However, the neural oscillatory mechanisms supporting this process in childhood remains poorly understood. While beta-band oscillations have been linked to statistical learning in visual and motor domains, it is unclear whether similar dynamics support auditory statistical learning in children. In this study, we recorded electroencephalography (EEG) from children aged 8-12 years as they listened to a continuous stream of trisyllabic nonwords (e.g., dapiku), where syllable order within each nonword was fixed (high predictability), but transitions between nonwords were variable (low predictability). Beta power was significantly lower for the more predictable second and third syllables relative to the less predictable first syllable. This effect emerged only after repeated exposure and was localised to left prefrontal electrodes. Beta power also correlated with post-exposure recognition accuracy. Additional learning-related modulations were observed in the theta-alpha and delta-theta bands, suggesting broader oscillatory engagement. These findings indicate that auditory statistical learning in middle childhood engages frequency-specific neural dynamics, with beta power modulations showing parallel effects to those observed in other modalities.

The brain integrates and transforms information from multiple senses to make optimal decisions, a process that is critical for navigating complex environments with perceptual uncertainty. Despite a growing consensus that individuals adapt flexibly to uncertain sensory input, whether increasing visual uncertainty influences the decision process itself or other, non-decision sensory processes during multisensory decision-making are unclear. Here, an audiovisual categorization task was used to examine the responses of human participants (N = 30) to visual and audiovisual stimuli under low-, medium-, and high-uncertainty conditions. Modeling the behavioral data using a drift‒diffusion model indicated that increased visual uncertainty in the audiovisual context decreased the evidence accumulation rate but had no effect on non-decision processes. Electrophysiological recordings confirmed and expanded upon these results: increased visual uncertainty in the audiovisual context reduced the amplitude during the late decision-making stage (300-380 msec) but had no effect on the amplitude during the early sensory encoding stage (140-220 msec). More importantly, electroencephalography analyses revealed that audiovisual integration in the early sensory encoding stage occurred robustly across all visual uncertainty conditions, whereas audiovisual integration in the late stage occurred only under medium and high visual uncertainty conditions. This study demonstrated that increased visual uncertainty modulates the decision process itself rather than early sensory encoding during multisensory decision-making. Moreover, multisensory integration strategies dynamically adapt to increasing visual uncertainty by engaging different mechanisms to maintain effective decision-making.

To examine the processes contributing to reading, we investigated neurophysiological letter coding in typically developing children (3.6-9.3 years) using an oddball fast periodic visual stimulation and a 32-channel electroencephalogram. Non-native (Georgian) letters appeared every fifth item in a stream of native (Russian) letters, presented at a frequency of 6 Hz. This contrast (foreign condition, n = 46) elicited significant discrimination responses at the frequency of non-native letters presentation - 1.2 Hz - and its harmonics, even in children who did not yet acquire reading skills. We also investigated native letter orientation sensitivity using 180-degree-rotated Russian letters in a stream of upright Russian letters (inverted condition, n = 42, overlap with foreign condition n = 37). Discrimination responses increased with age in both conditions but followed different trajectories. In the foreign condition, it significantly increased in the subgroup of pre-reading children and plateaued in older children. In the inverted condition, discrimination response emerged only in reading children and showed significant correlation with age in this subgroup. The results support two systems of tuning for letters: a coarse tuning system that differentiates native from foreign letters and develops in pre-reading age through environmental exposure, and an orientation tuning system that develops with reading acquisition.

Numeracy, the foundation of mathematical processing, can be divided into two subcategories: approximate (quantity estimation) and precise numeracy (exact quantity). Loss of numeracy is commonly comorbid with aphasia following stroke, yet little is known about the neural basis of this relationship. We employed a support vector regression lesion-symptom mapping (SVR-LSM) analysis with N = 104 left hemisphere chronic stroke survivors to investigate the neural relationship between approximate and precise numeracy with language ability. Our results highlight key differences between how approximate and precise numeracy overlap with language processing regions. Approximate numeracy does not show a significant relationship to aphasia or language related regions, while precise numeracy shares considerable neural overlap with language areas and co-varies significantly with aphasia severity. The results support a priori hypotheses that the intraparietal sulcus (IPS) is crucially involved in approximation and additionally implicate regions including angular gyrus (AG), precentral gyrus, and anterior fusiform gyrus. In contrast, precise numeracy was linked to damage to the inferior frontal gyrus (IFG), AG, and anterior temporal cortex, as well as the caudate nucleus, thalamus, and posterior temporal regions. Overall, we provide evidence of strong lesion-deficit associations demonstrating distinct neural patterns between precise and approximate numeracy impairments. Crucially, we demonstrate that these subcategories have contrasting relationships with language processing.

We report a rare case of sudden-onset psychiatric syndrome following a right thalamic ischemic event. Potential mechanisms involving both structural and functional thalamic disconnection are considered. A 51-year-old man was admitted to the Neurology Unit at the Azienda Ospedale-Università of Padova with sudden-onset confusion and amnesia, accompanied by visual and auditory hallucinations and emotional lability. An initial head CT scan showed no evidence of stroke; however, a follow-up MRI revealed a recent ischemic lesion in the right mediodorsal nucleus (MDN) of the thalamus. A brain [18F]FDG PET-MRI scan identified a small hypometabolic area in the right anterolateral frontal cortex. The prefrontal cortex was structurally and functionally disconnected by the thalamic lesion. Neuropsychological testing revealed deficits of executive functions, particularly in planning and abstract reasoning, as well as impairments in long-term verbal and visuospatial memory and deficits in the visuoperceptual domain. The patient was treated with risperidone and venlafaxine, leading to an improvement in psychotic symptoms at both discharge and follow-up. Understanding these network-level disruptions may offer valuable insights into therapeutic approaches and prognostic evaluation.

Perceiving the duration of events is a fundamental ability for everyday life. Traditional research has focused on the role of alpha oscillations as an endogenous pacemaker for the human internal clock, yet there is limited evidence supporting this idea. An alternative hypothesis proposes that alpha oscillations may underlie a sampling mechanism, where higher alpha frequencies correspond to increased information sampling, resulting in more accurate temporal judgments. In this study, we tested the internal clock versus sampling rate hypothesis by examining the relationship between Individual Alpha Frequency (IAF) and fine-grained time perception. Using resting Electroencephalography (EEG) and Signal Detection Theory (SDT), fifty healthy volunteers performed a time-discrimination task with 100 and 500 msec standard durations. Our results demonstrate that temporal sensitivity (d') but not temporal bias (c) is influenced by IAF, with higher IAF leading to more accurate time estimates (higher d'). The correlations were observed over frontocentral topographies consistent with previous reports of neural networks involved in time processing and were most pronounced at 100 msec relative to 500 msec, likely due to fluctuations in IAF across multiple cycles. In conclusion, our findings support the relationship between IAF and temporal sensitivity. These results challenge the pacemaker hypothesis and instead suggest a distributed mechanism where alpha oscillations enhance the precision of temporal sampling. Our study adds to the growing body of evidence highlighting the role of IAF in sensory sampling as a generative mechanism for temporal sensitivity as opposed to subjective time perception.

In this viewpoint letter, I critically examine the longstanding debate regarding the nature of mental imagery-specifically the tension between depictive and propositional theories-through the lens of recent neuroscientific findings. While early studies using neuroimaging were interpreted as supporting a depictive, perception-like model of visual imagery, emerging data from individuals with aphantasia present compelling counterevidence. These individuals, who report an absence of conscious visual imagery, nonetheless display decodable activity in early visual cortices during imagery-related tasks, prompting a reevaluation of the assumptions linking neural activation in V1 to subjective imagery. I suggest alternatives that support for a single- or a dual-process account of mental representation in the human brain.

Psychotic symptoms are well established across the amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD) spectrum and contribute to patient and carer distress and poorer prognosis. However, there are no objective tools to probe these symptoms and the underlying functional neurobiology has been unexplored to date. Leveraging clinical interview, neuropsychological testing, and a validated behavioural paradigm of visual misperception combined with connectome-wide fMRI analysis, we directly probed visual hallucinatory tendencies and the associated cognitive and functional connectivity signatures in ALS-FTD. In 82 participants across the ALS-FTD spectrum (24 ALS patients, 7 ALS-FTD, 31 behavioural-variant FTD [19 C9orf72 expansion carriers and 43 non-carriers] and 20 healthy controls), we showed that an ecologically valid behavioural task was sensitive to hallucinatory tendencies. We observed selective involvement of attentional deficits in visual misperception beyond the influence of executive function and psychomotor speed (r ranging from .344-.603; FDR-corrected at p < .05). Following quality control, data-driven whole-brain fMRI analysis in a subset of 26 patients converged to implicate the attentional systems, wherein abnormally heightened connectivity anchored in the attentional, default mode and executive control networks worsened as a function of visual misperception severity (FWE-corrected p = .042 with 10,000 permutations). Our findings underscore the critical role of attentional disruptions, characterised by altered interactions between top-down and bottom-up attentional, introspective, and salience detection processes, in ALS-FTD visual hallucinatory predisposition. Aligning with current models of hallucination generation postulated in schizophrenia, Parkinson's disease, and dementia with Lewy bodies, our findings point towards common neural underpinnings of psychosis vulnerability shared by ALS-FTD.

Subjective cognitive decline (SCD) has been proposed as a potential preclinical stage of Alzheimer's disease (AD) dementia. This study aimed to investigate whether objective impairments could be identified in SCD on highly demanding memory tasks and their possible associations with medial temporal lobe (MTL) volumes. The performance of 31 individuals with SCD and 29 healthy elderly with no worries of cognitive decline (HC) was compared on two experimental tasks assessing respectively face-name-occupation associative memory and spatial pattern separation. The diagnostic power of these tests in classifying cognitive status was assessed. In addition, a sub-group of 20 SCD and 19 HC underwent a 3T-MRI. Volumes of individual hippocampal subfields and surrounding cortices within the MTL were calculated and compared between the two groups. Finally, possible associations between brain volumes and performance on experimental tasks were evaluated. While traditional neuropsychological tests showed no significant between-group differences, SCDs obtained significantly lower scores than HCs on experimental tasks. These measures also correctly classified group membership with good overall accuracy. Volumetric data revealed significant between-group differences in specific hippocampal subfields (particularly CA1 and dentate gyrus) and surrounding cortices (particularly entorhinal and perirhinal cortices). Furthermore, lower scores on experimental tasks significantly correlated with reduced volumes in specific MTL sub-regions (particularly CA1 and perirhinal cortices). These findings provide the first evidence in SCD of an association between objective memory impairments in associative memory and spatial pattern separation and volume reductions in specific MTL sub-regions known to be primarily vulnerable to AD neuropathology.

Statistical Learning (SL) is an essential mechanism for speech segmentation. Individual differences in SL ability are associated with language acquisition. For instance, better SL correlated with a larger vocabulary size and impaired SL was found in populations with language impairments. The aim of the current study was to contribute to uncovering the underpinnings of individual differences in auditory SL for word segmentation. We hypothesized that individuals with better musical - specifically rhythmic - abilities would show better SL. Participants (N = 106) were exposed to an artificial language consisting of trisyllabic nonsense words. Electroencephalography (EEG) measures of neural entrainment to the auditory signal allow online assessment of SL. The current study used this method to measure individual SL performance during exposure. To assess individual differences, we linked the neural measure of SL to a battery of tests measuring rhythmic, musical, and cognitive abilities, as well as vocabulary size. We replicated earlier work, finding both online (neural) and offline (behavioral) evidence of SL in our sample. In contrast to our expectations regarding individual differences, we found evidence for the null hypothesis regarding correlations between the tests of rhythmic ability and the neural measurement of SL. Exploratory analyses concerning working memory remained inconclusive, while exploratory analyses regarding vocabulary size yielded moderate evidence for a small correlation with the neural measure of SL. Overall, our results suggest that linguistic SL is largely independent from abilities in other cognitive domains, including rhythmic processing and musical abilities, as measured within a sample of healthy, typically developed adults.

Reward processing is a neurocognitive process involving the evaluation of and response to rewarding stimuli, which is critical for learning and motivated behavior. This cognitive mechanism is also influenced by mental health. Intolerance of uncertainty (IU) is a dispositional tendency to perceive uncertainty as distressing and respond negatively to uncertain situations. Proposed as a transdiagnostic factor for internalizing disorders, IU may help explain shared features across these conditions. This study investigated the influence of IU on electrocortical responses to reward (feedback-related ERP) using the Doors Task, which incorporated varying levels of uncertainty (i.e., risk) regarding rewards. In 203 participants, we found that risk levels significantly influenced ERPs, particularly following reward feedback, with high-risk trials eliciting larger (i.e. more positive) ERPs compared to ambiguous or low-risk trials. While total IU did not correlate with feedback-related brain activity, its subfactors showed distinct effects after reward and no-reward feedback: higher prospective IU scores were associated with increased brain activity, whereas higher inhibitory IU scores were linked to decreased activity. These effects persisted after accounting for related internalizing traits, including worry, depression, and trait anxiety. Additionally, depressive symptoms were associated with blunted feedback-related ERPs, particularly following no-reward feedback. Taken together, the findings suggest a more nuanced and complex role of IU and its subfactors in reward processing and demonstrate the impact of risk on electrocortical responses to reward outcomes.

We examined how spatial processing is affected by attentional load during multitasking in a chronic patient who suffered a right hemisphere stroke six years before the testing. We employed standard paper-and-pencil tests for neglect along with a new version of a well-established computerized dual-task paradigm. The latter combined a spatial processing primary task (reporting lateralized visual targets) with a concurrent secondary task (categorizing visual/auditory stimuli). Attentional load was manipulated through top-down (secondary task) and bottom-up (target size in primary task) factors. Paper-and-pencil tests did not reveal contralesional omissions. In contrast, the dual-task paradigm demonstrated greater sensitivity in detecting asymmetric spatial processing. Surprisingly, contralesional omissions occurred despite primary and secondary task stimuli did not overlap in time (i.e., secondary task stimuli were presented after the disappearance of lateralized visual targets lasting 100 ms). While both top-down and bottom-up manipulations induced contralesional omissions, their effects differed according to target size. Increased attentional load from dual-tasking impaired perception of larger contralesional targets, whereas smaller targets elicited omissions even in single-task conditions without additional multitasking effects. In this patient, very different manipulations, the first involving top-down and exclusively cognitive factors and the second involving bottom-up and purely perceptual aspects, independently modulated the level of processing resources. Both can be exploited to exacerbate very subtle (yet potentially hazardous) spatial processing deficits.

Setting apart the neural properties of familiarity for both self and others' faces helps deepen our understanding of the cognitive, developmental, and theoretical dimensions of social dynamics and human identity. Motivated by this goal, we conducted a multivariate cross-classification EEG experiment where we tested whether individuals represent their own face as similar to other highly familiar faces or code self-faces through different familiarity processes. We compare the representational dynamics for self and other faces in both their current and past versions. Participants were presented highly variable faces of four familiarity categories (self, parent, close-friend and unknown) in two versions across lifespan: current and past images, which were taken 10 years ago. Linear discriminant classifiers were trained and tested on EEG patterns to discriminate familiar and unfamiliar faces. Time-resolved classification revealed that the neural representations of familiarity emerge before 200 msec post-stimulus onset and remains significant until 600 msec, independently of familiarity level and age. Further, our findings show that the temporal dynamics of familiarity is similar for self-faces and other highly familiar faces. Our study provides new insights into how the brain represents self-identity and suggest that important aspects of self-recognition, such as the familiarity of self-face, is supported by learning processes rather than privilege introspective mechanisms.

Tactile perception is a subjective experience, yet it can be physiologically quantified. This offers new avenues for studying sensory processing in contexts where verbal feedback is limited or unreliable. A growing body of research uses changes in pupil size, showing that stronger tactile stimuli lead to greater pupil dilation. Building on this, we investigated whether pupil responses could serve as an objective measure of tactile sensitivity. To explore this, we pharmacologically manipulated tactile sensitivity in healthy participants (n = 32). In separate sessions, an anaesthetic cream or a placebo cream was applied to one forearm. At the beginning and/or end of each session, Von Frey assessments and a vibrotactile detection task were conducted to confirm the efficacy of the anaesthetic cream in reducing tactile sensitivity. During each session, pupil responses to vibrotactile stimuli applied to both the cream and non-cream arms were recorded. Our results confirmed that the anaesthetic cream significantly reduced the perceived intensity of tactile stimulation, an effect that persisted throughout the session. Crucially, we observed weaker pupil dilation responses to vibrotactile stimuli applied to the anaesthetised arm compared to the placebo or non-cream arm. Exploratory analyses showed that participants for whom the anaesthetic cream was most effective in reducing tactile sensitivity also showed the weakest pupil responses when the anaesthetised arm was stimulated. Overall, these findings demonstrate that the pupil response is a reliable and objective index of tactile sensitivity, highlighting its potential for studying sensory processing in populations where verbal feedback is limited or unreliable.

The cerebellum, traditionally regarded as a part of the motor network, has recently been implicated in higher-level language processing and narrative comprehension. However, its role in complex bilingual narrative comprehension remains unexplored. A critical question is whether the cerebellum maintains consistent functional profiles across languages or adapts flexibly. In this study, we investigated the cross-language consistency and language-specific modulations in cerebellar activation and cortico-cerebellar functional connectivity in highly proficient Chinese-English bilinguals (N = 28) while they completed a narrative comprehension task in their first (L1) and second (L2) language. We found that the right posterior cerebellum, particularly the Crus I and Crus II, exhibited spatially consistent activation during narrative comprehension in both languages. Compared to meaningless material processing, this region showed increased connectivity with the cortical default mode network (DMN) during narrative comprehension, with significantly stronger connectivity with DMN during L1 processing compared to L2. Additionally, the connectivity between the narrative-sensitive cerebellar regions and the left inferior frontal gyrus (IFG) was positively correlated with L2 age of acquisition (AoA) during L2 processing. This association between the cerebellum with L2 AoA suggests that the cerebellum undergoes bilingual experience-dependent adaptations to support bilingual language processing. Our results suggest that the cerebellum flexibly adjusts its connectivity and pattern with the cerebral cortex during narrative comprehension across languages. The enhanced cortico-cerebellar collaboration during L2 processing reflects a compensatory neural mechanism tied to L2 AoA. This study underscores the cerebellum's flexible functional mechanisms in bilingual narrative comprehension and its adaptive role in late L2 acquisition.

Face processing deficits have mostly been documented in single cases/small samples, and rarely following brain tumours. Right hemisphere functions in general are under-investigated in brain tumour patients, despite the need to preserve them during surgery. We assessed anatomical correlates of a critical right hemisphere function, face processing, and specifically deficits in memorizing and recognizing unknown faces; decoding emotional expressions; and whether deficits are preferentially right lateralized, or could also be observed following left hemisphere damage.

Spatial cognition refers to the general ability to represent space, manipulate spatial information, and use concepts relating to this notion. Recent evidence suggests that brief multisensory training might improve this process, but the impact of long-term and intensive multisensory training on spatial cognition remains unexplored. The present study aims to examine the impact of musical training, a multisensory training involving the auditory function, on a body disorientation task with and without auditory cues. Thirty-eight participants were recruited and divided into two groups based on their musical experience (musicians and controls). They were asked to complete the Fukuda-Unterberger stepping task under four conditions: without any auditory input, and with auditory input originating at 0°, 45°, and 90° azimuth. This task is well known to create body disorientation as over the course of the task, the body position in space changes, unbeknownst to the participant. Results suggest that musicians are less susceptible to body disorientation, as measured in the stepping task, both in the absence and in the presence of auditory stimuli. The findings extend beyond recent research indicating that musical training can influence a wide range of auditory abilities, suggesting that it could also modulate a broader cognitive process, specifically spatial cognition. The demonstration that extensive multisensory training significantly enhances spatial cognition has relevance for rehabilitation in clinical settings.

Hand transplantation has been successful in restoring function in a select group of people, but the mechanisms by which the central nervous system integrates a new hand are unknown. We used event-related functional magnetic resonance imaging (fMRI) to assess brain activation related to actual and imagined hand movement, for a recipient (female, 60 years of age) of bilateral hand transplants. Investigation of a patient-specific network of sensorimotor cortical regions was conducted at a preoperative session, as well as at three assessments conducted over a 16-month, post-transplantation period. We detected significant activation for both actual and imagined hand movement, relative to a rest baseline, for both transplanted hands, at all three postoperative sessions. Activation was higher for actual movement than for imagined movement. Across the postoperative period, movement-related activation decreased in magnitude, relative to an imagined-movement baseline. Movement-related activation also became more focused, postoperatively, on hand-related brain regions, in contralateral sensorimotor cortex. Some movement-related brain activation was relatively stronger for the right hand, postoperatively, consistent with the fact that the patient had been right-handed, preoperatively. To our knowledge, this is the first hand-transplant recipient to exhibit more pronounced brain activation, post-transplantation, for actual movement relative to imagined movement. Overall, the findings suggest that, following hand transplantation, sensorimotor cortex returns to a more canonical functional organization, similar to that of healthy individuals.

The brain white matter microstructure of adult dyslexic readers is rarely studied, particularly in non-English speaking populations. This study investigated structural differences in white matter between Dyslexic and Control adults, all native Brazilian Portuguese speakers with a college-level education. We analyzed diffusion MRI data from 62 volunteers (26 with dyslexia and 36 controls), using deterministic and probabilistic approaches. Groups were matched for age, sex, handedness, and level of formal education. Deterministic analysis revealed significantly lower mean diffusivity and radial diffusivity in individuals with dyslexia in the posterior right hemisphere, particularly in core reading-related tracts such as the superior longitudinal fasciculus, inferior longitudinal fasciculus, and inferior fronto-occipital fasciculus. Probabilistic analysis showed widespread group differences in all diffusion measures investigated, including tracts not typically linked to dyslexia, and revealed alterations mainly in fractional anisotropy and radial diffusivity in posterior portions of tracts within the right hemisphere. Correlations between reading fluency and diffusion metrics revealed distinct neural behavioral patterns between groups, suggesting different neural mechanisms underlying reading abilities. These findings provide novel insights into white matter microstructure in dyslexia among Portuguese speakers and underscore the importance of cross-linguistic studies in reading disorders.

Adaptive mind-wandering is mostly future-oriented, and previous evidence suggests that self-reflection promotes future-oriented thought. This study investigates whether the activation of the Self (vs another person's) schema and of a representation of the future (vs present) time is followed by changes in the frequency and content of aware (self-caught) and unaware (probe-caught) mind-wandering. Four groups of healthy young adults viewed their current face (Present Self condition; N = 27) or aged face (Future Self condition; N = 28), or the current (Present Other condition; N = 29) or aged face of a famous person (Future Other condition; N = 27) and attributed personality traits to the individual they viewed. Participants then engaged in a Choice Reaction Time task with concomitant assessment of self-caught and probe-caught mind-wandering. We found that viewing an older compared to a younger face was associated with higher rates of aware mind-wandering, while viewing one's own compared to someone else's face was associated with higher rates of unaware mind-wandering, involving self-related and future-oriented thoughts. These findings show that both Self and Time schemata are associated with the frequency and content of off-task thought, with dissociable effects on aware and unaware forms of mind-wandering.

The term prosopagnosia was coined 78 years ago, in 1947. At that time few reports of a specific disorder of face recognition existed, the three most detailed being those of Wilbrand (1892), Hoff and Pötzl (1937), and Bodamer (1947). These laid the basis for much of our current thought about the manifestations of prosopagnosia, its associations, its structural basis, and theories about its functional mechanisms. However, since they were written in German and few current researchers are fluent in that language, these early works are relatively neglected today. In this review we discuss their highly detailed case descriptions, the prescient inductions they made from their clinical material, as well as their less successful speculations, with full translations provided as appendices. Familiarity with these older studies provides a perspective on the ongoing work in prosopagnosia.