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1.
Behav Ther ; 54(1): 1-13, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36608967

RESUMO

Although studies have identified differences between fear and disgust conditioning, much less is known about the generalization of conditioned disgust. This is an important gap in the literature given that overgeneralization of conditioned disgust to neutral stimuli may have clinical implications. To address this knowledge gap, female participants (n = 80) completed a Pavlovian conditioning procedure in which one neutral food item (conditioned stimulus; CS+) was followed by disgusting videos of individuals vomiting (unconditioned stimulus; US) and another neutral food item (CS-) was not reinforced with the disgusting video. Following this acquisition phase, there was an extinction phase in which both CSs were presented unreinforced. Importantly, participants also evaluated generalization stimuli (GS+, GS-) that resembled, but were distinct from, the CS after each conditioning phase. As predicted, the CS+ was rated as significantly more disgusting and fear inducing than the CS- after acquisition and this pattern persisted after extinction. However, disgust ratings of the CS+ after acquisition were significantly larger than fear ratings. Participants also rated the GS+ as significantly more disgusting, but not fear inducing, than the GS- after acquisition. However, this effect was not observed after extinction. Disgust proneness did predict a greater increase in disgust and fear ratings of the CS+ relative to the CS- after acquisition and extinction. In contrast, trait anxiety predicted only higher fear ratings to the CS+ relative to the CS- after acquisition and extinction. Disgust proneness nor trait anxiety predicted the greater increase in disgust to the GS+ relative to the GS- after acquisition. These findings suggest that while conditioned disgust can generalize, individual difference variables that predict generalization remain unclear. The implications of these findings for disorders of disgust are discussed.


Assuntos
Asco , Humanos , Feminino , Individualidade , Extinção Psicológica , Condicionamento Clássico , Transtornos de Ansiedade
2.
Sci Rep ; 13(1): 631, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36635491

RESUMO

Visual search is a ubiquitous activity in real-world environments. Yet, traditionally, visual search is investigated in tightly controlled paradigms, where head-restricted participants locate a minimalistic target in a cluttered array that is presented on a computer screen. Do traditional visual search tasks predict performance in naturalistic settings, where participants actively explore complex, real-world scenes? Here, we leverage advances in virtual reality technology to test the degree to which classic and naturalistic search are limited by a common factor, set size, and the degree to which individual differences in classic search behavior predict naturalistic search behavior in a large sample of individuals (N = 75). In a naturalistic search task, participants looked for an object within their environment via a combination of head-turns and eye-movements using a head-mounted display. Then, in a classic search task, participants searched for a target within a simple array of colored letters using only eye-movements. In each task, we found that participants' search performance was impacted by increases in set size-the number of items in the visual display. Critically, we observed that participants' efficiency in classic search tasks-the degree to which set size slowed performance-indeed predicted efficiency in real-world scenes. These results demonstrate that classic, computer-based visual search tasks are excellent models of active, real-world search behavior.


Assuntos
Atenção , Realidade Virtual , Humanos , Individualidade , Movimentos Oculares , Meio Ambiente , Percepção Visual
3.
Sci Rep ; 13(1): 675, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36635384

RESUMO

Somatosensory experience is an important component of emotion, playing a prominent role in many traditional emotion theories. Nonetheless, and despite the extensive literature on the influence of individual differences in emotional processing, the relation between personality traits and emotion-related somatosensation has received little attention. Here, we addressed this question in a large sample of healthy individuals through the "bodily maps of emotion" behavioural paradigm, in which participants indicated the location and extent of their body sensations for the 6 basic and 4 additional social emotions (contempt, envy, pride, shame). We found that emotional somatosensation in specific body areas, including the heart, the stomach, and the head, was related to specific personality factors, particularly antisocial attitudes and impulsivity. Moreover, the similarity of individual participants' maps to the group-average was likewise negatively correlated with antisocial tendencies. Overall, our results suggest that differences in individuals' sensitivity to somatosensation from different body areas, as well as the typicality of their topographical patterns, may partly underlie variation in higher-order social and affective traits.


Assuntos
Transtorno da Personalidade Antissocial , Emoções , Comportamento Impulsivo , Individualidade , Humanos , Fenótipo , Sensação
4.
Accid Anal Prev ; 182: 106955, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36630858

RESUMO

Drivers have spare visual capacity in driving, and often this capacity is used for engaging in secondary in-car tasks. Previous research has suggested that the spare visual capacity could be estimated with the occlusion method. However, the relationship between drivers' occlusion times and in-car glance duration preferences has not been sufficiently investigated for granting occlusion times the role of an estimate of spare visual capacity. We conducted a driving simulator experiment (N = 30) and investigated if there is an association between drivers' occlusion times and in-car glance durations in a given driving scenario. Furthermore, we explored which factors and variables could explain the strength of the association. The findings suggest an association between occlusion time preferences and in-car glance durations in visually and cognitively low demanding unstructured tasks but that this association is lost if the in-car task is more demanding. The findings might be explained by the inability to utilize peripheral vision for lane-keeping when conducting in-car tasks and/or by in-car task structures that override drivers' preferences for the in-car glance durations. It seems that the occlusion technique could be utilized as an estimate of drivers' spare visual capacity in research - but with caution. It is strongly recommended to use occlusion times in combination with driving performance metrics. There is less spare visual capacity if this capacity is used for secondary tasks that interfere with the driver's ability to utilize peripheral vision for driving or preferences for the in-car glance durations. However, we suggest that the occlusion method can be a valid method to control for inter-individual differences in in-car glance duration preferences when investigating the visual distraction potential of, for instance, in-vehicle infotainment systems.


Assuntos
Atenção , Condução de Veículo , Humanos , Automóveis , Acidentes de Trânsito/prevenção & controle , Individualidade
5.
Br J Soc Psychol ; 62 Suppl 1: 1-20, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36637066

RESUMO

This article introduces the special issue 'Towards a Social Psychology of Precarity' that develops an orienting lens for social psychologists' engagement with the concept. As guest editors of the special issue, we provide a thematic overview of how 'precarity' is being conceptualized throughout the social sciences, before distilling the nine contributions to the special issue. In so doing, we trace the ways in which social psychologists are (dis)engaging with the concept of precarity, yet too, explore how precarity constitutes, and is embedded within, the discipline itself. Resisting disciplinary decadence, we collectively explore what a social psychology of precarity could be, and view working with/in precarity as fundamental to addressing broader calls for the social responsiveness of the discipline. The contributing papers, which are methodologically pluralistic and provide rich conceptualisations of precarity, challenge reductionist individualist understandings of suffering and coping and extend social science theorizations on precarity. They also highlight the ways in which social psychology remains complicit in perpetuating different forms of precarity, for both communities and academics. We propose future directions for the social psychological study of precarity through four reflexive questions that we encourage scholars to engage with so that we may both work with/in, and intervene against, 'the precarious'.


Assuntos
Adaptação Psicológica , Psicologia Social , Humanos , Individualidade
6.
PeerJ ; 11: e14598, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36710873

RESUMO

Gut microbiota studies often rely on a single sample taken per individual, representing a snapshot in time. However, we know that gut microbiota composition in many animals exhibits intra-individual variation over the course of days to months. Such temporal variations can be a confounding factor in studies seeking to compare the gut microbiota of different wild populations, or to assess the impact of medical/veterinary interventions. To date, little is known about the variability of the koala (Phascolarctos cinereus) gut microbiota through time. Here, we characterise the gut microbiota from faecal samples collected at eight timepoints over a month for a captive population of South Australian koalas (n individuals = 7), and monthly over 7 months for a wild population of New South Wales koalas (n individuals = 5). Using 16S rRNA gene sequencing, we found that microbial diversity was stable over the course of days to months. Each koala had a distinct faecal microbiota composition which in the captive koalas was stable across days. The wild koalas showed more variation across months, although each individual still maintained a distinct microbial composition. Per koala, an average of 57 (±16) amplicon sequence variants (ASVs) were detected across all time points; these ASVs accounted for an average of 97% (±1.9%) of the faecal microbial community per koala. The koala faecal microbiota exhibits stability over the course of days to months. Such knowledge will be useful for future studies comparing koala populations and developing microbiota interventions for this regionally endangered marsupial.


Assuntos
Microbiota , Phascolarctidae , Animais , Phascolarctidae/genética , Individualidade , RNA Ribossômico 16S/genética , Austrália
7.
Proc Natl Acad Sci U S A ; 120(4): e2202262120, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36669108

RESUMO

The coordinate frames for color and motion are often defined by three dimensions (e.g., responses from the three types of human cone photoreceptors for color and the three dimensions of space for motion). Does this common dimensionality lead to similar perceptual representations? Here we show that the organizational principles for the representation of hue and motion direction are instead profoundly different. We compared observers' judgments of hue and motion direction using functionally equivalent stimulus metrics, behavioral tasks, and computational analyses, and used the pattern of individual differences to decode the underlying representational structure for these features. Hue judgments were assessed using a standard "hue-scaling" task (i.e., judging the proportion of red/green and blue/yellow in each hue). Motion judgments were measured using a "motion-scaling" task (i.e., judging the proportion of left/right and up/down motion in moving dots). Analyses of the interobserver variability in hue scaling revealed multiple independent factors limited to different local regions of color space. This is inconsistent with the influences across a broad range of hues predicted by conventional color-opponent models. In contrast, variations in motion scaling were characterized by more global factors plausibly related to variation in the relative weightings of the cardinal spatial axes. These results suggest that although the coordinate frames for specifying color and motion share a common dimensional structure, the perceptual coding principles for hue and motion direction are distinct. These differences might reflect a distinction between the computational strategies required for the visual analysis of spatial vs. nonspatial attributes of the world.


Assuntos
Percepção de Cores , Individualidade , Humanos , Percepção de Cores/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Benchmarking , Peso Corporal , Cor , Estimulação Luminosa/métodos
8.
PLoS One ; 18(1): e0280072, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36630441

RESUMO

We introduce a novel approach to assess habitual comparison processes, while distinguishing between different types of comparison standards. Several comparison theories (e.g., social) suggest that self-evaluations use different standards to inform self-perception and are associated with wellbeing and personality. We developed the Comparison Standards Scale for Appearance (CSS-A) to examine self-reported engagement with social, temporal, criteria-based, dimensional, and counterfactual comparisons for upward and downward standards in relation to appearance. The scale was completed by three hundred participants online alongside measures of appearance schemas, social comparison evaluations, depression, anxiety, stress, self-esteem, physical self-concept, narcissism, and perfectionism. The CSS-A was found to reliably assess individual differences in upward and downward comparison frequency and affective impact for multiple comparison standards. In line with theory, CSS-A upward comparisons were more frequent than downward comparisons and coincided with negative (versus positive) affective impact. Comparison intensity (i.e., comparison frequency × discrepancy) predicted negative and positive affective impact for upward and downward comparisons, respectively. This relationship was partially mediated by appearance concern for upward comparisons (a composite of appearance schemas and physical self-concept), yet moderated by negativity for downward comparisons (a composite of depression, anxiety, stress, and self-esteem). We offer a framework for measuring the comparison process that warrants further research on underlying comparison processes, for which the CSS(-A) and experience sampling methods should serve as useful tools.


Assuntos
Individualidade , Autoimagem , Humanos , Autoavaliação (Psicologia) , Transtornos da Personalidade , Padrões de Referência
9.
Sci Rep ; 13(1): 1419, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36697448

RESUMO

Humans form complex societies in which we routinely engage in social decision-making regarding the allocation of resources among ourselves and others. One dimension that characterizes social decision-making in particular is whether to prioritize self-interest or respect for others-proself or prosocial. What causes this individual difference in social value orientation? Recent developments in the social dual-process theory argue that social decision-making is characterized by its underlying domain-general learning systems: the model-free and model-based systems. In line with this "learning" approach, we propose and experimentally test the hypothesis that differences in social preferences stem from which learning system is dominant in an individual. Here, we used a non-social state transition task that allowed us to assess the balance between model-free/model-based learning and investigate its relation to the social value orientations. The results showed that proselfs depended more on model-based learning, whereas prosocials depended more on model-free learning. Reward amount and reaction time analyses showed that proselfs learned the task structure earlier in the session than prosocials, reflecting their difference in model-based/model-free learning dependence. These findings support the learning hypothesis on what makes differences in social preferences and have implications for understanding the mechanisms of prosocial behavior.


Assuntos
Relações Interpessoais , Comportamento Social , Humanos , Tomada de Decisões , Individualidade , Aprendizagem
10.
Sci Rep ; 13(1): 1680, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36717571

RESUMO

Studies have demonstrated systematic individual differences in the degree of semantic reliance (SR) when reading aloud exception words in adult skilled readers. However, the origins of individual differences in reading remain unclear. Using a connectionist model of reading, this study investigated whether oral vocabulary knowledge may affect the degree of SR as a potential source of individual differences in reading. Variety in oral vocabulary knowledge was simulated by training the model to learn the mappings between spoken and meaning word forms with different vocabulary sizes and quantities of exposure to these vocabularies. The model's SR in the reading aloud task was computed. The result demonstrated that the model with varying amounts of oral exposure and vocabulary sizes had different levels of SR. Critically, SR was able to predict the performance of the model on reading aloud and nonword reading, which assimilated behavioural reading patterns. Further analysis revealed that SR was largely associated with the interaction between oral vocabulary exposure and oral vocabulary size. When the amount of exposure was limited, SR significantly increased with vocabulary sizes but decreased then with vocabulary sizes. Overall, the simulation results provide the first computational evidence of the direct link between oral vocabulary knowledge and the degree of SR as a source of individual differences in reading.


Assuntos
Leitura , Vocabulário , Individualidade , Semântica , Aprendizagem
11.
PeerJ ; 11: e14821, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36718455

RESUMO

Background: Although researchers have begun to consider metacognitive insight during face matching, little is known about the underlying mechanism. Here, I investigated whether objective ability, as well as self-assessed ability, were able to predict metacognitive performance, that is, the ability to differentiate correct and incorrect responses in terms of confidence. In addition, I considered whether a training intervention resulted in improvements to both face matching performance and metacognitive insight. Methods: In this experiment (N = 220), participants completed a face matching task, with either a diagnostic feature training course or a control course presented at the halfway point. In addition, a second face matching task, as well as a self-report questionnaire regarding ability, were completed to provide measures of objective and self-assessed ability respectively. Results: Higher self-assessed ability with faces, as well as higher objective ability with face matching, predicted better metacognitive performance, i.e., greater confidence in correct, in comparison with incorrect, responses. This pattern of results was evident both when objective ability was measured through performance on the same task used to measure metacognitive insight and when a different task was used. Finally, the training intervention failed to produce improvements in face matching performance and showed no evidence of altering metacognitive ability. Discussion: The current work begins to address the mechanism underlying individual differences in metacognitive insight during face matching. Although support was provided for a competence-based account, where better face matchers showed greater performance on the task and were more successful in monitoring their performance, further work might focus on decoupling task performance and competence in order to more conclusively explain why some people are more insightful than others.


Assuntos
Metacognição , Humanos , Metacognição/fisiologia , Individualidade , Análise e Desempenho de Tarefas
12.
Neurosci Biobehav Rev ; 144: 104996, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36526032

RESUMO

Social evolution and the dynamics of social interactions have previously been studied under the frameworks of quantitative genetics and behavioural ecology. In quantitative genetics, indirect genetic effects of social partners on the socially plastic phenotypes of focal individuals typically lack crucial detail already included in treatments of social plasticity in behavioural ecology. Specifically, whilst focal individuals (e.g. receivers) may show variation in their 'responsiveness' to the social environment, individual social partners (e.g. signallers) may have a differential 'impact' on focal phenotypes. Here we propose an integrative framework, that highlights the distinction between responsiveness versus impact in indirect genetic effects for a range of behavioural traits. We describe impact and responsiveness using a reaction norm approach and provide statistical models for the assessment of these effects of focal and social partner identity in different types of social interactions. By providing such a framework, we hope to stimulate future quantitative research investigating the causes and consequences of social interactions on phenotypic evolution.


Assuntos
Individualidade , Comportamento Social , Animais , Comportamento Animal , Fenótipo , Meio Social , Evolução Biológica
13.
Cognition ; 232: 105333, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36508992

RESUMO

Matching identity in images of unfamiliar faces is difficult: Images of the same person can look different and images of different people can look similar. Recent studies have capitalized on individual differences in the ability to distinguish match (same ID) vs. mismatch (different IDs) face pairs to inform models of face recognition. We addressed two significant gaps in the literature by examining the stability of individual differences in both sensitivity to identity and response bias. In Study 1, 210 participants completed a battery of four tasks in each of two sessions separated by one week. Tasks varied in protocol (same/different, lineup, sorting) and stimulus characteristics (low vs. high within-person variability in appearance). In Study 2, 148 participants completed a battery of three tasks in a single session. Stimuli were presented simultaneously on some trials and sequentially on others, introducing short-term memory demands. Principal components analysis revealed two components that were stable across time and tasks: sensitivity to identity and bias. Analyses of response times suggest that individual differences in bias reflect decision-making processes. We discuss the implications of our findings in applied settings and for models of face recognition.


Assuntos
Reconhecimento Facial , Reconhecimento Psicológico , Humanos , Reconhecimento Psicológico/fisiologia , Individualidade , Face , Reconhecimento Facial/fisiologia , Memória de Curto Prazo
15.
J Affect Disord ; 320: 178-195, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36174784

RESUMO

BACKGROUND: Affective neuroscience (AN) theory assumes the existence of seven basic emotional systems (i.e., SEEKING, ANGER, FEAR, CARE, LUST, SADNESS, PLAY) that are common to all mammals and evolutionarily determined to be tools for survival and, in general, for fitness. Based on the AN approach, the Affective Neuroscience Personality Scales (ANPS) questionnaire was developed to examine individual differences in the defined basic emotional systems. The current systematic review aims to examine the use of ANPS in clinical contexts attempting to define those behavioral elements associated with underlying stable personality traits. METHODS: The systematic review was conducted following the PRISMA statements. PubMed and PsycInfo were used for research literature from March 2003 to November 2021. RESULTS: Forty-four studies including ANPS were identified from 1763 studies reviewed. Sixteen studies met the inclusion criteria. LIMITATIONS: The review comprised some papers with incomplete psychological assessments (e.g., lack of other measures in addition to the ANPS) and missing information (e.g., on the [sub]samples), which may affect the generalizability of findings. CONCLUSION: Specific endophenotypes and/or patterns of emotional/motivational systems were found for several mental disorders. Specifically, endophenotypes emerged for the Depressive and Autism Spectrum Disorders, Borderline and Avoidant Personality Disorders, type I and II Bipolar Disorders, and the Obsessive-Compulsive Disorder. The endophenotypes can provide useful reflective elements for both psychodiagnosis and intervention. Overall, the current study may represent an attempt to contribute to the understanding of the basic emotional systems involved in the psychopathological manifestations identified by AN.


Assuntos
Emoções , Transtornos da Personalidade , Humanos , Transtornos da Personalidade/diagnóstico , Transtornos da Personalidade/psicologia , Transtorno Ciclotímico , Individualidade , Ira , Personalidade
16.
Synapse ; 77(1): e22253, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36121749

RESUMO

Anorexia nervosa (AN) is a mental illness with the highest rates of mortality and relapse, and no approved pharmacological treatment. Using an animal model of AN, called activity-based anorexia (ABA), we showed earlier that a single intraperitoneal injection of ketamine at a dose of 30 mg/kg (30mgKET), but not 3 mg/kg (3mgKET), has a long-lasting effect upon adolescent females of ameliorating anorexia-like symptoms through the following changes: enhanced food consumption and body weight; reduced running and anxiety-like behavior. However, there were also individual differences in the drug's efficacy. We hypothesized that individual differences in ketamine's ameliorative effects involve drebrin A, an F-actin-binding protein known to be required for the activity-dependent trafficking of NMDA receptors (NMDARs). We tested this hypothesis by electron microscopic quantifications of drebrin A immunoreactivity at excitatory synapses of pyramidal neurons (PN) and GABAergic interneurons (GABA-IN) in deep layer 1 of prefrontal cortex (PFC) of these mice. Results reveal that (1) the areal density of excitatory synapses on GABA-IN is greater for the 30mgKET group than the 3mgKET group; (2) the proportion of drebrin A+ excitatory synapses is greater for both PN and GABA-IN of 30mgKET than 3mgKET group. Correlation analyses with behavioral measurements revealed that (3) 30mgKET's protection is associated with reduced levels of drebrin A in the cytoplasm of GABA-IN and higher levels at extrasynaptic membranous sites of PN and GABA-IN; (5) altogether pointing to 30mgKET-induced homeostatic plasticity that engages drebrin A at excitatory synapses of both PN and GABA-IN.


Assuntos
Anorexia Nervosa , Ketamina , Camundongos , Feminino , Animais , Ketamina/farmacologia , Anorexia Nervosa/tratamento farmacológico , Anorexia Nervosa/metabolismo , Anorexia/tratamento farmacológico , Anorexia/metabolismo , Individualidade , Sinapses/metabolismo , Modelos Animais de Doenças , Córtex Pré-Frontal/metabolismo , Citoplasma/metabolismo , Ácido gama-Aminobutírico/metabolismo
17.
J Vis ; 22(13): 3, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36458961

RESUMO

Human face recognition is robust even under conditions of extreme lighting and in situations where there is high noise and uncertainty. Mooney faces are a canonical example of this: Mooney faces are two-tone shadow-defined images that are readily and holistically recognized despite lacking easily segmented face features. Face perception in such impoverished situations-and Mooney face perception in particular-is often thought to be supported by comparing encountered faces to stored templates. Here, we used a classification image approach to measure the templates that observers use to recognize Mooney faces. Visualizing these templates reveals the regions and structures of the image that best predict individual observer recognition, and they reflect the underlying internal representation of faces. Using this approach, we tested whether there are classification images that are consistent from session to session, whether the classification images are observer-specific, and whether they allow for pattern completion of holistic representations even in the absence of an underlying signal. We found that classification images of Mooney faces were indeed non-random (i.e., consistent session from session) within each observer, but they were different between observers. This result is in line with previously proposed existence of face templates that support face recognition, and further suggests that these templates may be unique to each observer and could drive idiosyncratic individual differences in holistic face recognition. Moreover, we found classification images that reflected information within the blank regions of the original Mooney faces, suggesting that observers may fill in missing information using idiosyncratic internal information about faces.


Assuntos
Reconhecimento Facial , Individualidade , Humanos , Reconhecimento Psicológico , Iluminação , Incerteza
18.
Sci Rep ; 12(1): 20754, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456622

RESUMO

Transcranial direct current stimulation (tDCS) has the potential to modulate cognitive training in healthy aging; however, results from various studies have been inconsistent. We hypothesized that inter-individual differences in baseline brain state may contribute to the varied results. We aimed to explore whether baseline resting-state dynamic functional connectivity (rs-dFC) and/or conventional resting-state static functional connectivity (rs-sFC) may be related to the magnitude of cognitive aftereffects of tDCS. To achieve this aim, we used data from our double-blind randomized sham-controlled cross-over tDCS trial in 25 healthy seniors in which bifrontal tDCS combined with cognitive training had induced significant behavioral aftereffects. We performed a backward regression analysis including rs-sFC/rs-dFC measures to explain the variability in the magnitude of tDCS-induced improvements in visual object-matching task (VOMT) accuracy. Rs-dFC analysis revealed four rs-dFC states. The occurrence rate of a rs-dFC state 4, characterized by a high correlation between the left fronto-parietal control network and the language network, was significantly associated with tDCS-induced VOMT accuracy changes. The rs-sFC measure was not significantly associated with the cognitive outcome. We show that flexibility of the brain state representing readiness for top-down control of object identification implicated in the studied task is linked to the tDCS-enhanced task accuracy.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Humanos , Individualidade , Progressão da Doença , Encéfalo , Cognição
19.
Proc Biol Sci ; 289(1989): 20222036, 2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36541170

RESUMO

The remarkable similarities in cognitive performance between teleosts and mammals suggest that the underlying cognitive mechanisms might also be similar in these two groups. We tested this hypothesis by assessing the effects of the brain-derived neurotrophic factor (BDNF), which is critical for mammalian cognitive functioning, on fish's cognitive abilities. We found that individual differences in zebrafish's learning abilities were positively correlated with bdnf expression. Moreover, a CRISPR/Cas9 mutant zebrafish line that lacks the BDNF gene (bdnf-/-) showed remarkable learning deficits. Half of the mutants failed a colour discrimination task, whereas the remaining mutants learned the task slowly, taking three times longer than control bdnf+/+ zebrafish. The mutants also took twice as long to acquire a T-maze task compared to control zebrafish and showed difficulties exerting inhibitory control. An analysis of habituation learning revealed that cognitive impairment in mutants emerges early during development, but could be rescued with a synthetic BDNF agonist. Overall, our study indicates that BDNF has a similar activational effect on cognitive performance in zebrafish and in mammals, supporting the idea that its function is conserved in vertebrates.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Peixe-Zebra , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Peixe-Zebra/genética , Individualidade , Cognição , Mamíferos/metabolismo
20.
Nature ; 612(7941): 739-747, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36517598

RESUMO

Exercise exerts a wide range of beneficial effects for healthy physiology1. However, the mechanisms regulating an individual's motivation to engage in physical activity remain incompletely understood. An important factor stimulating the engagement in both competitive and recreational exercise is the motivating pleasure derived from prolonged physical activity, which is triggered by exercise-induced neurochemical changes in the brain. Here, we report on the discovery of a gut-brain connection in mice that enhances exercise performance by augmenting dopamine signalling during physical activity. We find that microbiome-dependent production of endocannabinoid metabolites in the gut stimulates the activity of TRPV1-expressing sensory neurons and thereby elevates dopamine levels in the ventral striatum during exercise. Stimulation of this pathway improves running performance, whereas microbiome depletion, peripheral endocannabinoid receptor inhibition, ablation of spinal afferent neurons or dopamine blockade abrogate exercise capacity. These findings indicate that the rewarding properties of exercise are influenced by gut-derived interoceptive circuits and provide a microbiome-dependent explanation for interindividual variability in exercise performance. Our study also suggests that interoceptomimetic molecules that stimulate the transmission of gut-derived signals to the brain may enhance the motivation for exercise.


Assuntos
Eixo Encéfalo-Intestino , Dopamina , Exercício Físico , Microbioma Gastrointestinal , Motivação , Corrida , Animais , Camundongos , Encéfalo/citologia , Encéfalo/metabolismo , Dopamina/metabolismo , Endocanabinoides/antagonistas & inibidores , Endocanabinoides/metabolismo , Células Receptoras Sensoriais/metabolismo , Eixo Encéfalo-Intestino/fisiologia , Microbioma Gastrointestinal/fisiologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/psicologia , Modelos Animais , Humanos , Estriado Ventral/citologia , Estriado Ventral/metabolismo , Corrida/fisiologia , Corrida/psicologia , Recompensa , Individualidade
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