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An implemented predictive coding model of lexico-semantic processing explains the dynamics of univariate and multivariate activity within the left ventromedial temporal lobe during reading comprehension.
During language comprehension, the larger neural response to unexpected versus expected inputs is often taken as evidence for predictive coding-a specific computational architecture and optimization algorithm proposed to approximate probabilistic inference in the brain. However, other predictive processing frameworks can also account for this effect, leaving the unique claims of predictive coding untested. In this study, we used MEG to examine both univariate and multivariate neural activity in response to expected and unexpected inputs during word-by-word reading comprehension. We further simulated this activity using an implemented predictive coding model that infers the meaning of words from their orthographic form. Consistent with previous findings, the univariate analysis showed that, between 300 and 500 ms, unexpected words produced a larger evoked response than expected words within a left ventromedial temporal region that supports the mapping of orthographic word-forms onto lexical and conceptual representations. Our model explained this larger evoked response as the enhanced lexico-semantic prediction error produced when prior top-down predictions failed to suppress activity within lexical and semantic "error units". Critically, our simulations showed that despite producing minimal prediction error, expected inputs nonetheless reinstated top-down predictions within the model's lexical and semantic "state" units. Two types of multivariate analyses provided evidence for this functional distinction between state and error units within the ventromedial temporal region. First, within each trial, the same individual voxels that produced a larger response to unexpected inputs between 300 and 500 ms produced unique temporal patterns to expected inputs that resembled the patterns produced within a pre-activation time window. Second, across trials, and again within the same 300-500 ms time window and left ventromedial temporal region, pairs of expected words produced spatial patterns that were more similar to one another than the spatial patterns produced by pairs of expected and unexpected words, regardless of specific item. Together, these findings provide compelling evidence that the left ventromedial temporal lobe employs predictive coding to infer the meaning of incoming words from their orthographic form during reading comprehension.
“We are here too”: Experiences and perceived support needs of adolescent siblings of Paediatric oncology inpatients
AbstractBackgroundAdolescent siblings of children and young people (CYP) with cancer are at increased risk of psychosocial difficulties, yet many remain overlooked and unsupported. This project aimed to explore the experiences and perceived needs of adolescent siblings of paediatric oncology inpatients to inform service improvement recommendations for sibling support.MethodsSemi‐structured interviews were conducted with 10 siblings of CYP previously admitted to a paediatric oncology ward. Interviews were transcribed verbatim and analysed using reflexive thematic analysis. The findings were reviewed in consultation with staff and used to identify pragmatic/feasible recommendations for improving sibling support, organized using the three‐tier ‘Pediatric Psychosocial Preventative Health Model’ (PPPHM; Families, Systems & Health, 2006, 24, 381).ResultsAn overarching narrative of siblings wanting to feel part of the cancer journey was found, including their family's experience on the ward, with three key themes: (i) “what about me?”: overlooked and unseen, (ii) “always changing, never knowing”: the challenge of uncertainty and (iii) “let me be part of it all”: togetherness, communication and connection. These findings informed sibling support recommendations. Such recommendations included providing psychosocial screening, resources and opportunities for family time/communication and developmentally appropriate information to all siblings (universal support), monitoring psychosocial difficulties, siblings having someone to talk to and fostering family and peer connection for siblings requiring additional support (targeted support) and offering one‐to‐one psychological support and family therapy for persistent and/or escalating distress (clinical/treatment support).ConclusionsBased on the experiences of siblings, a range of sibling support recommendations have been identified. Implementation and evaluation of these recommendations are warranted.
Credit and blame for AI-generated content: Effects of personalization in four countries.
Generative artificial intelligence (AI) raises ethical questions concerning moral and legal responsibility-specifically, the attributions of credit and blame for AI-generated content. For example, if a human invests minimal skill or effort to produce a beneficial output with an AI tool, can the human still take credit? How does the answer change if the AI has been personalized (i.e., fine-tuned) on previous outputs produced without AI assistance by the same human? We conducted a preregistered experiment with representative sampling (N = 1802) repeated in four countries (United States, United Kingdom, China, and Singapore). We investigated laypeople's attributions of credit and blame to human users for producing beneficial or harmful outputs with a standard large language model (LLM), a personalized LLM, or no AI assistance (control condition). Participants generally attributed more credit to human users of personalized versus standard LLMs for beneficial outputs, whereas LLM type did not significantly affect blame attributions for harmful outputs, with a partial exception among Chinese participants. In addition, UK participants attributed more blame for using any type of LLM versus no LLM. Practical, ethical, and policy implications of these findings are discussed.
Bilingual Toddlers' Vocabulary Growth Interacts with Existing Knowledge and Cross-Linguistic Similarity.
We explored whether bilingual toddlers make use of semantic and phonological overlap between their languages to learn new words. We analysed cross-sectional and longitudinal CDI data on the words understood and produced by 1.0 to 3.0-year-old bilingual toddlers with English and one additional language. Cognates were more likely to be understood and produced compared to non-cognates. Cognate effects were modulated by whether the toddler knew the translation equivalent in the other language, highlighting that young learners are sensitive to the similarities across their languages. Additionally, exploratory analyses suggest that children with smaller vocabularies rely more on translation equivalents to support the acquisition of difficult words. Children with larger vocabulary sizes exhibited no preference for translation equivalents in comprehension, and a preference for new concepts in production. The rapid acceleration of vocabulary growth in the second year of life may explain this developmental change in translation equivalent preference.
Psychiatric symptoms in COVID-19-positive individuals in the general population: Trajectories of depression, anxiety, and insomnia.
The present study investigates differences in the trajectories of anxiety, depression, and sleep problems among infected versus non-infected case-controlled individuals. Patients who tested positive for COVID-19 were selected from a representative sample in Norway (N > 10,000). In total, 126 of these individuals were infected during the project period, and this group was analyzed at T5 (May 2021). Of these positive cases, those who had completed both PHQ-9 and GAD-7 at all three measurement points were selected for longitudinal analysis using multilevel modeling. There was a significant difference at T5 between those who had tested positive for COVID-19 and matched controls. Anxiety and depression were reduced among those who tested positive, but there were no differences in trajectory when compared to matched controls. Limitations include the use of self-report measures and the assessment of symptoms at a time when strict virus mitigation protocols were in place. The present findings indicate that individuals who test positive for COVID-19 exhibit higher levels of depressive symptoms after restrictions are lifted. However, comparison of anxiety and depression symptom trajectories with matched controls reveals that both groups exhibited stable or slightly decreased symptoms.
Going ‘meta’: a systematic review of metacognition and functional neurological disorder
In functional neurological disorder (FND), there is a fundamental disconnect between an apparently intact nervous system and the individuals’ ability to consistently perform motor actions, perceive sensory signals and/or access effective cognition. Metacognition, the capacity to self-evaluate cognitive performance, appears highly relevant to FND pathophysiology. Poor metacognition is a potential mechanism via which abnormal models of self and the state of the world could arise and persist unchecked. There is therefore a justified enthusiasm that studies of metacognition may give substance to FND’s intangible nature. However, many assume an impairment in metacognition even though experimental studies are still in their infancy. This systematic review provides an analytical checkpoint of the evidence after the first five years of experimental work. We firstly summarize current methods for testing metacognition, prerequisite knowledge that allows readers to independently evaluate the evidence. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we then screened the 21 articles on this topic and review the experimental data of the eight studies that specifically tested metacognition in subjects with FND. Questionnaire metrics used to estimate global metacognition and general confidence in FND revealed a mixed picture of low or normal confidence. Of the five studies that used performance-controlled metrics, the gold-standard to estimate local metacognition in FND, four found metacognition to be equivalent to healthy controls and one paper supported impaired metacognition. We consequently try and broaden the debate and discuss alternative headline scenarios. We review how positive studies may offer insight and debate whether null studies could represent false negatives. However, since most studies find equivalent metacognition to controls, we also discuss whether metacognition could be intact and how this could inform mechanistic models of FND and have potential clinical utility. In summary, this review highlights signal of interest within the data, exposes current limitations and flags the many open questions.
Behavioural changes in frontotemporal dementia and their cognitive and neuroanatomical correlates.
Behavioural changes are a central feature of frontotemporal dementia (FTD); they occur in both behavioural-variant (bvFTD) and semantic dementia (SD)/semantic-variant primary progressive aphasia subtypes. In this study, we addressed two current clinical knowledge gaps; (i) are there qualitative or clear distinctions between behavioural profiles in bvFTD and SD, and (ii) what are the precise roles of the prefrontal cortex and anterior temporal lobes in supporting social behaviour? Resolving these conundrums is crucial for improving diagnostic accuracy and for the development of targeted interventions to treat challenging behaviours in FTD. Informant questionnaires to assess behavioural changes included the Cambridge Behavioural Inventory-Revised and two targeted measures of apathy and impulsivity. Participants completed a detailed neuropsychological battery to permit investigation of the relationship between cognitive status (including social-semantic knowledge, general semantic knowledge and executive function) with behaviour change in FTD. To explore changes in regional grey matter volume, a subset of patients had structural MRI. Diagnosis-based group comparisons were supplemented by a transdiagnostic approach which encompassed the spectrum of bvFTD, SD and "mixed" or intermediate cases. Such an approach is sensitive to the systematic graded variation in FTD and allows the neurobiological underpinnings of behaviour change to be explored across an FTD spectrum. We found a wide range of behavioural changes across FTD. Although quantitatively more severe on average in bvFTD, as expected, the item-level analyses found no evidence for qualitative differences in behavioural profiles or "behavioural double dissociations" between bvFTD and SD. Comparisons of self and informant ratings revealed strong discrepancies in the perspective of the caregiver versus patient. Logistic regression revealed that neuropsychological measures had better discriminative accuracy for bvFTD versus SD than caregiver-reported behavioural measures. A principal component analysis of all informant questionnaire domains extracted three components, interpreted as reflecting: (1) apathy, (2) challenging behaviours and (3) activities of daily living. More severe apathy in both FTD subtypes was associated with (a) increased levels of impaired executive function and (b) anterior cingulate cortex atrophy. Questionnaire ratings of impaired behaviour did not correlate with either anterior temporal lobe atrophy or degraded social-semantic knowledge. Together, these findings highlight the presence of a wide range of behavioural changes in both bvFTD and SD, which vary by degree rather than quality. We recommend a transdiagnostic approach for future studies of the neuropsychological and neuroanatomical underpinnings of behavioural deficits in FTD.
Parenting Experiences in the Context of Parental Bipolar Disorder: A Systematic Review and Meta-Synthesis of the Qualitative Literature
Abstract Parental bipolar disorder (BD) is associated with an increased risk of mental health problems in children. Despite the urgent need for clear guidance on how best to support parents with BD, current research lacks a unified analysis of the challenges and needs faced by these parents and their children. This review aims to explore the impact of BD on experiences of parent–child interactions or relationships to inform effective policies and interventions. Following a preregistered PROSPERO protocol, we searched Medline, Embase, PsycINFO, SCOPUS, and CINAHL for qualitative studies on parents with BD and their children (under 19 years) published since 1994. Each study was independently screened and jointly assessed for quality using the Critical Appraisal Skills Program. Our thematic synthesis entailed coding in NVivo, followed by collaborative theme generation on the Miro platform. We reviewed 19 studies, of which 9 studies reported on parents, 8 on children, and 2 on both parents and children. Our analysis generated four themes: (1) "The multifaceted landscape of parenting with BD," which outlines how mood swings affect parenting in diverse ways; (2) "The evolving dynamic of child-parent relationship amidst parental BD," including how children adapt and grow in understanding and responsibility in response to their parent’s BD; (3) "The dual nature of childcare for parents with BD," which explores how childcare impacts parents’ emotions and motivations, bringing both uplifting and challenging effects; (4) "Navigating parental challenges in the context of BD," highlighting the importance of open communication, self-reflection, and timely, unbiased support to mitigate challenges associated with parental BD. This qualitative synthesis focuses specifically on the parenting experiences of families affected by parental BD. It highlights the complex, dynamic impact of BD on parenting behaviors and children’s coping mechanisms, calling for tailored therapeutic interventions that benefit both parents and children. The scope of our study is limited by factors such as a predominance of Western perspectives and an underrepresentation of fathers’ experiences, highlighting the need for more diverse research in this area.
Effects of noise and metabolic cost on cortical task representations.
Cognitive flexibility requires both the encoding of task-relevant and the ignoring of task-irrelevant stimuli. While the neural coding of task-relevant stimuli is increasingly well understood, the mechanisms for ignoring task-irrelevant stimuli remain poorly understood. Here, we study how task performance and biological constraints jointly determine the coding of relevant and irrelevant stimuli in neural circuits. Using mathematical analyses and task-optimized recurrent neural networks, we show that neural circuits can exhibit a range of representational geometries depending on the strength of neural noise and metabolic cost. By comparing these results with recordings from primate prefrontal cortex (PFC) over the course of learning, we show that neural activity in PFC changes in line with a minimal representational strategy. Specifically, our analyses reveal that the suppression of dynamically irrelevant stimuli is achieved by activity-silent, sub-threshold dynamics. Our results provide a normative explanation as to why PFC implements an adaptive, minimal representational strategy.