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The brain neuromodulatory systems consist of small regions in the brainstem, pontine nucleus, and basal forebrain that regulate cognitive behavior by releasing neurotransmitters. Ascending projections from the brainstem and basal forebrain regions spread these neurotransmitters to broad areas of the central nervous system within the frontal cortex, anterior cingulate, or hippocampus, signaling a range of neural pathways. The modulator effect executed in these brain areas, together with the interplay between the systems, is crucial for regulating and adjusting many cognitive and behavioral functions. Neurodegenerative disease processes frequently affect the normal functioning of these modulator circuitries, directly leading to or contributing to the appearance of cognitive and neuropsychiatric symptoms. Even though these neuromodulatory systems’ impairment and imbalance happen early, further efforts to understand better their neurobiological basis are warranted . Hence, this chapter aims to review the role of the neuromodulatory systems in behavior and cognition and how their dysfunction shapes the neurodegenerative dementia phenotype.
The human brain makes up just 2% of body mass but consumes closer to 20% of the body’s energy. Nonetheless, it is significantly more energy-efficient than most modern computers. Although these facts are well-known, models of cognitive capacities rarely account for metabolic factors. In this paper, we argue that metabolic considerations should be integrated into cognitive models. We distinguish two uses of metabolic considerations in modeling. First, metabolic considerations can be used to evaluate models. Evaluative metabolic considerations function as explanatory constraints. Metabolism limits which types of computation are possible in biological brains. Further, it structures and guides the flow of information in neural systems. Second, metabolic considerations can be used to generate new models. They provide: a starting point for inquiry into the relation between brain structure and information processing, a proof-of-concept that metabolic knowledge is relevant to cognitive modeling, and potential explanations of how a particular type of computation is implemented. Evaluative metabolic considerations allow researchers to prune and partition the space of possible models for a given cognitive capacity or neural system, while generative considerations populate that space with new models. Our account suggests cognitive models should be consistent with the brain’s metabolic limits, and modelers should assess how their models fit within these bounds. Our account offers fresh insights into the role of metabolism for cognitive models of mental effort, philosophical views of multiple realization and medium independence, and the comparison of biological and artificial computational systems.
Most children recover from mild traumatic brain injury (mTBI), but some experience persistent neurocognitive effects. Understanding is limited due to methodological differences and a lack of pre-injury data. The study aimed to assess changes in neurocognitive outcomes in children following mTBI compared to orthopedic injury (OI) and non-injured (NI) controls, while accounting for pre-injury functioning.
Method:
Data were drawn from the Adolescent Brain and Cognitive Development (ABCD) study, a prospective longitudinal cohort. The sample included children with mTBI between the 1-year and 2-year follow-ups (n = 83), identified by parent report of head injury with memory loss or loss of consciousness, compared to children who experienced OI within the same period (n = 231) and an NI control group (n = 218). Changes in neurocognitive outcomes from baseline to the 2-year follow-up between groups (mTBI vs. OI; mTBI vs. NI) were estimated using linear mixed-effects models, accounting for demographic, behavioral, genetic, and white matter microstructural covariates.
Results:
At baseline prior to injury, the mTBI group demonstrated better performance on picture vocabulary and crystallized composite scores than the OI group. At post-injury, after adjusting for pre-injury baseline differences, children who sustained an mTBI were no different in any measure of neurocognitive outcomes compared to OI and NI controls.
Conclusions:
The findings highlight the importance of accounting for pre-injury differences when evaluating neurocognitive outcomes following pediatric mTBI. Neurocognitive differences within a year post-injury may be more related to pre-existing individual factors rather than the injury itself, underscoring the need for a comprehensive approach in studying pediatric mTBI.
Major depressive disorder (MDD) is a heterogeneous with underlying mechanisms that are insufficiently studied. We aimed to identify functional connectivity (FC)-based subtypes of MDD and investigate their biological mechanisms.
Methods
Consensus clustering of FC patterns was applied to a population of 829 MDD patients from the REST-Meta-MDD database, with validity assessed across multiple dimensions, including atlas replication, cross-validated classification, and drug-naïve subgroup analysis. Regression models were used to quantify FC alterations in each MDD subgroup compared with 770 healthy controls, and to analyze spatial associations between FC alterations and publicly available gene transcriptomic and neurotransmitter receptor/transporter density databases.
Results
Two stable MDD subtypes emerged: hypoconnectivity (n = 527) and hyperconnectivity (n = 299), which had both shared and distinct regions with remarkable FC alterations (i.e. epicenters) in the default mode network.
There were several common enriched genes (e.g. axon/brain development, synaptic transmission/organization, etc.) related to FC alterations in both subtypes. However, glial cell and neuronal differentiation genes were specifically enriched in the hypoconnectivity and hyperconnectivity subtypes, respectively.
Both subtypes showed spatial associations between FC alterations and serotonin receptor/transporter density. In the hypoconnectivity subtype, FC alterations correlated with GABA and acetylcholine receptor densities, while norepinephrine transporter and glutamate receptor densities were linked to the hyperconnectivity subtype.
Conclusions
Our findings suggested the presence of two neuroimaging subtypes of MDD characterized by hypoconnectivity or hyperconnectivity, demonstrating robust reproducibility. The two subtypes had both shared and distinct genetic mechanisms and neurotransmitter receptor/transporter profiles, suggesting potential clinical implications for this heterogeneous disorder.
To investigate potential contributors to mental fatigue after aneurysmal subarachnoid hemorrhage (aSAH) and angiographically negative subarachnoid hemorrhage (anSAH), with a focus on information processing speed, attentional control, and psychological distress.
Method:
This observational study included 101 patients (70 aSAH, 31 anSAH) and 86 controls. Neuropsychological assessments and questionnaires were conducted five months post-SAH. Mental and physical fatigue were assessed with the Dutch Multifactor Fatigue Scale, information processing speed and attentional control with the Trail Making Test and Vienna Test System Reaction Time and Determination Test, and psychological distress with the Hospital Anxiety and Depression Scale.
Results:
Patients reported significantly higher mental and physical fatigue than controls (p < .001) and information processing speed and attentional control were significantly lower (p < .05), with no differences between aSAH and anSAH groups. Severe mental fatigue was present in 55.7% of patients with aSAH and 61.3% of patients with anSAH, significantly exceeding the prevalence of severe physical fatigue (p < .05). Higher mental fatigue correlated with worse attentional control in aSAH and with lower information processing speed in anSAH. Both mental and physical fatigue correlated with psychological distress, particularly after anSAH.
Conclusions:
The factors related to mental fatigue appear to differ based on the type of SAH, potentially involving problems in information processing speed and attentional control, psychological distress, or both. This study emphasizes the need for individualized rehabilitation strategies addressing both cognitive and psychological factors in managing mental fatigue after SAH.
Negative symptoms in schizophrenia, particularly motivational deficits, pose significant challenges to treatment and recovery. Despite their profound impact on functional outcomes, these symptoms remain poorly understood and inadequately addressed by current interventions.
Aims
The CHANSS (Characterising Negative Symptoms in Schizophrenia) study aims to dissect the cognitive mechanisms underlying motivational impairments by focusing on three interconnected domains: executive cognition, motivational cognition and meta-cognition.
Method
This large, international, cross-sectional study recruits a heterogeneous sample of patients across illness stages – from first-episode psychosis to treatment-resistant schizophrenia – and uses a comprehensive cognitive battery, clinical scales, self-report measures and computerised cognitive tasks. Four novel tasks assess key processes in motivated behaviour: option generation, reward-based decision-making, risk sensitivity and performance self-evaluation. By incorporating control for secondary influences like depression, psychosis, sedation and illness chronicity, the study seeks to identify distinct cognitive and behavioural subtypes within motivational dysfunction.
Results
CHANSS tests the hypothesis that specific patient profiles exhibit predominant impairments in one or more cognitive domains, which may differentially affect goal-directed behaviour. The study’s design allows exploration of hierarchical relationships between cognitive processes, such as how neurocognitive deficits may cascade to impair motivation and self-evaluation.
Conclusions
Ultimately, CHANSS aims to advance mechanistic understanding of motivational deficits in schizophrenia and pave the way for personalised, targeted interventions. Its findings may inform future clinical trials and contribute to a shift away from one-size-fits-all approaches towards more effective, stratified treatment strategies in schizophrenia.
While prior studies have analyzed Skin Picking Disorder as a unitary condition, little research has been done examining clinical and neurocognitive characteristics of specific subtypes. The objective of this study is to analyze differences in impulsivity, emotional regulation, symptom severity, cognitive performance, and the presence of comorbid psychiatric conditions between focused and automatic subtypes of Skin Picking Disorder.
Methods
83 adults aged 18–65 with skin picking disorder were enrolled at the University of Chicago and separated into 4 skin picking subtype groups based on high or low levels of focused and automatic picking scores on the Milwaukee Inventory for the Dimension of Adult Skin Picking. The 4 subtype groups were separated using K-means clustering. Each group completed the same clinical and neurocognitive assessments. ANOVA or Chi-Squared tests were used to analyze differences in assessment outcomes.
Results
Higher focused picking scores were significantly associated with greater symptom severity and impairment. Differences in levels of automatic/focused picking were not associated with impulsivity, emotional/behavior regulations, or neurocognitive outcomes.
Conclusions
The findings suggest that focused skin pickers are likely to have more impairment due to their behavior compared to automatic or mixed pickers; however, overall, the groups did not differ in clinical or neurocognitive measures. Thus, it is unclear whether focused and automatic picking are particularly useful clinically in subtyping skin picking disorder.
This Element deals with the relationship between cognition, understood as the process of acquiring and developing knowledge, and diverse types of conspiracy theories, or short, 'CTs'. Section 1 lays the groundwork for the analysis by determining four components of narrative argumentative framing in CTs, of which the first three are constitutive for all CTs, with a fourth representing the 'optional' collective action-guiding “scenario” component. Section 2 exemplifies manifestations of these components by discussing contemporary and historical 'hoax' and 'asserting' CTs and 'empowering' CTs. Section 3 takes a cognitive-evolutionist and pragmatic view at the conditions for the 'success' of CT scenarios. In conclusion. Section 4 formulates lessons for countering the effects of socially detrimental CTs by deconstructing them and by obstructing their dissemination.
Subtle behavioral and cognitive symptoms precede schizophrenia (SCZ) and appear in individuals with elevated risk based on polygenic risk scores (SCZ-PRS) and family history of psychosis (SCZ-FH). However, most SCZ-PRS studies focus on European ancestry youth, limiting generalizability. Furthermore, it remains unclear whether SCZ-FH reflects common-variant polygenic risk or broader SCZ liability.
Methods
Using baseline data from the Adolescent Brain Cognitive Development (ABCD) study, we investigated associations of SCZ-FH and SCZ-PRS with cognitive, behavioral, and emotional measures from NIH-Toolbox, Child Behavior Checklist (CBCL), and Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS) for 9,636 children (mean age = 9.92 yrs, 47.4% female), specifically, 5,636 European, 2,093 African, and 1,477 Admixed American ancestry individuals.
Results
SCZ-FH was associated with SCZ-PRS (b = 0.05, FDR-p = 0.02) and subthreshold psychotic symptoms (b = 0.46, FDR-p = 0.01) in European youth, higher CBCL scores (b range = 0.36–0.6, FDR-p < 0.001), and higher odds of multiple internalizing and externalizing disorders (OR = 1.10–1.22, FDR-p < 0.001) across ancestries. SCZ-PRS was associated with lower cognition across ancestries (b = −0.43, FDR-p = 0.02), higher CBCL total problems, anxious/depressed, rule-breaking and aggressive behaviors in European youth (b range = 0.16–0.33, FDR-p < 0.04), and depressive disorders in Admixed American youth (OR = 1.37, FDR-p = 0.02). Results remained consistent when SCZ-PRS and SCZ-FH were jointly modeled. Some SCZ-FH associations weakened when income-to-needs was accounted for, suggesting that SCZ-FH may capture both genetic and environmental influences.
Conclusions
SCZ-FH showed associations with broad psychopathology, while SCZ-PRS was associated with cognition and specific symptoms in European youth. Findings highlight their complementary role in SCZ risk assessment and the need to improve PRS utility across ancestries.
Evolutionary theory and especially evolutionary psychology have been recruited to explain and justify women’s constrained social roles and the restrictions historically placed upon them in mass societies. This chapter, on scientific grounds, challenges three myths allegedly emerging from empirical research: the myth of female intellectual inferiority, the myth of female domesticity, and the myth of female natural monogamy. While there are anatomical, physiological, and psychological differences between men and women, reflecting their different reproductive strategies, the overuse of the principle of comparative advantage has resulted in the subjection and exploitation of women in nearly all known societies.
Few studies examine the relationship between physical activity, multiple physical fitness domains (cardiorespiratory fitness, strength, speed), and cognition. Our objective was to investigate the association between physical activity and executive function in middle-aged and older adults and examine whether modifiable physical fitness components explain the relationship between physical activity and cognition.
Method:
Self-reported moderate-to-vigorous physical activity and objective measures of cardiorespiratory fitness (2-minute walk test), strength (grip strength), speed (4-meter walk test), and executive function were collected from 623 adults within the Human Connectome Project–Aging (ages 36 – 100 years; mean = 59.2 years; 57.8% female). Relative importance metrics, multiple regression, and conditional process analysis were used to examine relationships of age, physical activity, and physical fitness with executive function.
Results:
Greater physical fitness was related to better executive function performance (β = 0.28, p < .001). Physical activity was not associated with executive function (β = −0.04, p = .16). There was an indirect relationship between physical activity and executive function through physical fitness (ab = 0.02, 95% CI: 0.004 – 0.04). This association was explained primarily by the indirect association of cardiorespiratory fitness with physical activity and executive function. The indirect association of cardiorespiratory fitness with physical activity and executive function was significant in older study participants (mean (59 years) and + 1 SD (74 years)), but not younger (−1 SD (44 years)), although between-group comparisons were not significant.
Conclusions:
These data highlight potential differential associations with cognition when considering physical activity and physical fitness, and the importance of considering multiple domains of physical fitness in relation to physical activity and cognitive performance.
This systematic review and meta-analysis aimed to review existing measures of subjective cognition during menopause and to estimate the correlation between subjective and objective cognition in perimenopausal and postmenopausal women.
Method:
Eligible studies reported scores for at least one subjective and objective measure of cognition for perimenopausal or postmenopausal women. EMBASE, Medline, and PsycINFO were searched for eligible studies on November 22nd 2024. The risk of bias in individual studies was evaluated using a modified QUADAS-2 form. The results of the review were summarized in narrative form. Studies that reported correlations between subjective and objective cognition were synthesized using a multilevel meta-analysis.
Results:
The sample included 5629 participants over 24 studies, including 295 perimenopausal women, 5086 postmenopausal women, and 248 women across mixed peri- and post-menopausal samples. Twelve measures of subjective cognition were used across studies. Six studies were included in the meta-analysis. A small significant correlation was observed between subjective cognition and objective measures of learning efficiency (r = .12; CI = .02 to .23). Correlations across other cognitive domains were non-significant.
Conclusions:
Our findings suggest subjective cognition may be associated with performance on measures of learning efficiency, offering a starting point for further research on menopausal brain fog. The present findings highlight the need for a reliable measure of subjective cognitive symptoms associated with menopause. Additionally, a better characterization of the neuropsychological profile of menopausal brain fog is needed to progress research in this field and ultimately improve clinical support for women experiencing these symptoms.
Healthy sleep contributes to better cognitive functioning in children. This study sought to investigate the role of pre-injury sleep disturbance as a predictor or moderator of cognitive functioning across 6 months post-injury in children with mild traumatic brain injury (mTBI) or orthopedic injury (OI).
Method:
Participants were 143 children with mTBI and 74 with OI, aged 8 – 16 years, prospectively recruited from the Emergency Departments of two children’s hospitals in Ohio, USA. Parents rated their children’s pre-injury sleep retrospectively using the Sleep Disorders Inventory for Students. Children completed the National Institutes of Health (NIH) Toolbox Cognition Battery at 10 days and 3 and 6 months post-injury.
Results:
Group differences in both overall performance and reaction time on the Flanker Inhibitory Control and Attention Test varied significantly as a function of the level of pre-injury sleep disturbance as well as time since injury. At the 10 day visit, among children with worse pre-injury sleep, mTBI was associated with slower reaction times relative to OI. Among children with worse pre-injury sleep, those with mTBI improved over time while those with OI did not. Main effects of pre-injury sleep and time since injury were found for several other NIH Toolbox subtests, with poorer performance associated with worse pre-injury sleep and early vs. later timepoints.
Conclusions:
These results suggest that pre-existing sleep disturbances and mTBI are jointly associated with poorer executive functioning post-injury. Interventions to improve sleep might help mitigate the effects of mTBI on children’s cognitive functioning.
Research indicates that demographic (e.g., age, education) and sociocultural (e.g., acculturation) factors can impact neuropsychological test performance among ethnoculturally diverse adults. Some studies suggest that greater acculturation to the United States (U.S.) is associated with better neurocognitive functioning, though no meta-analysis to date has examined this relationship. This review provides a comprehensive synthesis of the literature and determines the magnitude of the relationship between acculturation and neuropsychological test performance.
Method:
A literature search explored all published articles through January 1, 2024, using three databases (i.e., PubMED/MEDLINE, PsycInfo, PsycNET). Data to calculate study effect sizes (i.e., Fisher’s z) were extracted from in-text results, tables, and figures.
Results:
Findings (k = 18 included in quantitative analyses) revealed a small to medium (r = 0.29, partial r = 0.20, p < .01), statistically significant relationship between higher U.S. acculturation and better neuropsychological test performance. Moderation analyses indicated that language of testing emerged as a significant moderator, testing in English yielded larger effect sizes compared to testing in other languages (B = 0.29, p < .05).
Discussion:
Neuropsychological test performance is significantly associated with U.S. acculturation, and results suggest that the magnitude may vary depending on study methodologies and samples (e.g., ethnocultural group, U.S. born vs. immigrant) examined. The current review also provides recommendations for incorporating acculturation assessment into clinical practice and highlights the need to examine the clinical utility of acculturation tools in conjunction with neuropsychological tests to assist in clinical decision-making with ethnoculturally diverse populations.
This Element describes the development of a Theory of Mind, or mentalizing, in infancy and early childhood. Theory of Mind is a key social cognitive ability that permits children to predict and explain human behaviors by attributing mental states to other people. Understanding mental states gradually progresses from basic desires to false beliefs. The Element reviews the proximal and distal cognitive and social determinants that facilitate early Theory of Mind development. Discoveries in neuroscience contribute to understanding the ontogeny of Theory of Mind. This Element presents an overview of the main theoretical accounts of Theory of Mind development and offers suggestions for future research.
The book’s introduction explains the history of thought experiments in philosophy. It also describes Hans Christian Ørsted’s interactions with Kierkegaard and his influence on Kierkegaard’s concept of Tankeexperiment. The introduction outlines the ways in which thought experiments make thoughts meaningful by providing immediate presentations.
This chapter distinguishes the work of thought experiments in exemplifying concepts from their role in aiding cognition of regulative ideas. Contemporary interest in thought experiments as a “method of cases” treats thought experiments as providing instances or exemplars. For regulative ideas as Kant understands them, however, no observable instances or exemplars are possible. Nevertheless, thought experiments can direct attention toward regulative ideas negatively (by distinguishing them from what is observable) or positively by indicating a direction for extrapolation or ongoing inquiry. These positive uses are forms of cognition. The distinction between regulative and constitutive concepts matters for thought experiments that deal with regulative ideas such as the self – for example, for thought experiments about personal identity, where a number of objections to the use of thought experiments have been raised. I argue in this chapter that some of these objections can be answered by distinguishing regulative from constitutive concepts.
This chapter proposes that thought experiments are a cognitive apparatus and situates this view among contemporary accounts of thought experiment. I set forward the project of the book, which is to (1) propose a new account of thought experiments as a method and (2) trace the historical foundations of the term and concept of “thought experiment” from Kant through Ørsted to Kierkegaard. I define “cognition” [Erkenntnis] for Kant as a synthesis of concepts with intuitions and propose that Kierkegaard, like Kant and Ørsted, views thought experiments as useful for achieving cognitions. I introduce the term Tanke-experiment in Kierkegaard and suggest why it has been little emphasized by Kierkegaard scholars and remains widely unacknowledged in contemporary descriptions of the history of thought experiment.
The conclusion outlines key points in the book. On a Kantian-Kierkegaardian account, thought experiments lead to presentations that justify calling a thought experiment an experience, though not an empirical or sensory one. Without a sensible object, we can nevertheless have givenness, or presence, but not existence. Cognition, for that reason, is not necessarily truthful: although object-directed, cognition on its own does not justify belief in any particular object’s existence. My conclusion that thought experiments provide cognition rather than knowledge echoes Michael Stuart’s claim that thought experiments increase understanding. Cognition is a common basis for knowledge in Kant, but it is not the same thing as knowledge. The conclusion also draws implications for how we understand faith (religious belief) in Kierkegaard and how thought experiments make sense of the complexity of reality.
Rationalist accounts of thought experiment in epistemology offer an alternative to the more predominantly empiricist approaches in philosophy of science. In this chapter, I will pose a Kantian critique of recent rationalist accounts of intellectual intuition. Some epistemologists have recently argued that intellectual intuitions can provide prima facie justification for judgments. In this chapter, I highlight some promising elements of recent rationalist accounts, especially the proposal that there can be nonsensory presentations analogous to empirical perceptions. If they are right, then thought experiments can provide new experiential content even without empirical confirmation. However, I also draw attention to Kant’s objections to the possibility of purely intellectual intuitions.