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1.
Biol Psychiatry Glob Open Sci ; 4(1): 326-335, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38298803

RESUMEN

Background: The nature of cognitive flexibility deficits in obsessive-compulsive disorder (OCD), which historically have been tested with probabilistic reversal learning tasks, remains elusive. Here, a novel deterministic reversal task and inclusion of unmedicated patients in the study sample illuminated the role of fixed versus uncertain rules/contingencies and of serotonergic medication. Additionally, our understanding of probabilistic reversal was enhanced through theoretical computational modeling of cognitive flexibility in OCD. Methods: We recruited 49 patients with OCD, 21 of whom were unmedicated, and 43 healthy control participants matched for age, IQ, and gender. Participants were tested on 2 tasks: a novel visuomotor deterministic reversal learning task with 3 reversals (feedback rewarding/punishing/neutral) measuring accuracy/perseveration and a 2-choice visual probabilistic reversal learning task with uncertain feedback and a single reversal measuring win-stay and lose-shift. Bayesian computational modeling provided measures of learning rate, reinforcement sensitivity, and stimulus stickiness. Results: Unmedicated patients with OCD were impaired on the deterministic reversal task under punishment only at the first and third reversals compared with both control participants and medicated patients with OCD, who had no deficit. Perseverative errors were correlated with OCD severity. On the probabilistic reversal task, unmedicated patients were only impaired at reversal, whereas medicated patients were impaired at both the learning and reversal stages. Computational modeling showed that the overall change was reduced feedback sensitivity in both OCD groups. Conclusions: Both perseveration and increased shifting can be observed in OCD, depending on test conditions including the predictability of reinforcement. Perseveration was related to clinical severity and remediated by serotonergic medication.

2.
Sci Rep ; 13(1): 5534, 2023 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-37015952

RESUMEN

Humans exhibit distinct risk preferences when facing choices involving potential gains and losses. These preferences are believed to be subject to neuromodulatory influence, particularly from dopamine and serotonin. As neuromodulators manifest circadian rhythms, this suggests decision making under risk might be affected by time of day. Here, in a large subject sample collected using a smartphone application, we found that risky options with potential losses were increasingly chosen over the course of the day. We observed this result in both a within-subjects design (N = 2599) comparing risky options chosen earlier and later in the day in the same individuals, and in a between-subjects design (N = 26,720) showing our effect generalizes across ages and genders. Using computational modelling, we show this diurnal change in risk preference reflects a decrease in sensitivity to increasing losses, but no change was observed in the relative impacts of gains and losses on choice (i.e., loss aversion). Thus, our findings reveal a striking diurnal modulation in human decision making, a pattern with potential importance for real-life decisions that include voting, medical decisions, and financial investments.


Asunto(s)
Toma de Decisiones , Asunción de Riesgos , Humanos , Masculino , Femenino , Dopamina , Inversiones en Salud , Simulación por Computador
3.
Transl Psychiatry ; 12(1): 271, 2022 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-35820995

RESUMEN

Disruptions of self-regulation are a hallmark of numerous psychiatric disorders. Here, we examine the relationship between transdiagnostic dimensions of psychopathology and changes in self-regulation in the early phase of the COVID-19 pandemic. We used a data-driven approach on a large number of cognitive tasks and self-reported surveys in training datasets. Then, we derived measures of self-regulation and psychiatric functioning in an independent population sample (N = 102) tested both before and after the onset of the COVID-19 pandemic, when the restrictions in place represented a threat to mental health and forced people to flexibly adjust to modifications of daily routines. We found independent relationships between transdiagnostic dimensions of psychopathology and longitudinal alterations in specific domains of self-regulation defined using a diffusion decision model. Compared to the period preceding the onset of the pandemic, a symptom dimension related to anxiety and depression was characterized by a more cautious behavior, indexed by the need to accumulate more evidence before making a decision. Instead, social withdrawal related to faster non-decision processes. Self-reported measures of self-regulation predicted variance in psychiatric symptoms both concurrently and prospectively, revealing the psychological dimensions relevant for separate transdiagnostic dimensions of psychiatry, but tasks did not. Taken together, our results are suggestive of potential cognitive vulnerabilities in the domain of self-regulation in people with underlying psychiatric difficulties in face of real-life stressors. More generally, they also suggest that the study of cognition needs to take into account the dynamic nature of real-world events as well as within-subject variability over time.


Asunto(s)
COVID-19 , Trastornos Mentales , Autocontrol , Ansiedad/psicología , Humanos , Trastornos Mentales/epidemiología , Pandemias
4.
J Child Psychol Psychiatry ; 63(12): 1591-1601, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35537441

RESUMEN

BACKGROUND: Computational research had determined that adults with obsessive-compulsive disorder (OCD) display heightened action updating in response to noise in the environment and neglect metacognitive information (such as confidence) when making decisions. These features are proposed to underlie patients' compulsions despite the knowledge they are irrational. Nonetheless, it is unclear whether this extends to adolescents with OCD as research in this population is lacking. Thus, this study aimed to investigate the interplay between action and confidence in adolescents with OCD. METHODS: Twenty-seven adolescents with OCD and 46 controls completed a predictive-inference task, designed to probe how subjects' actions and confidence ratings fluctuate in response to unexpected outcomes. We investigated how subjects update actions in response to prediction errors (indexing mismatches between expectations and outcomes) and used parameters from a Bayesian model to predict how confidence and action evolve over time. Confidence-action association strength was assessed using a regression model. We also investigated the effects of serotonergic medication. RESULTS: Adolescents with OCD showed significantly increased learning rates, particularly following small prediction errors. Results were driven primarily by unmedicated patients. Confidence ratings appeared equivalent between groups, although model-based analysis revealed that patients' confidence was less affected by prediction errors compared to controls. Patients and controls did not differ in the extent to which they updated actions and confidence in tandem. CONCLUSIONS: Adolescents with OCD showed enhanced action adjustments, especially in the face of small prediction errors, consistent with previous research establishing 'just-right' compulsions, enhanced error-related negativity, and greater decision uncertainty in paediatric-OCD. These tendencies were ameliorated in patients receiving serotonergic medication, emphasising the importance of early intervention in preventing disorder-related cognitive deficits. Confidence ratings were equivalent between young patients and controls, mirroring findings in adult OCD research.


Asunto(s)
Trastorno Obsesivo Compulsivo , Adulto , Humanos , Adolescente , Niño , Teorema de Bayes , Trastorno Obsesivo Compulsivo/epidemiología , Conducta Compulsiva , Toma de Decisiones/fisiología , Aprendizaje
5.
Curr Top Behav Neurosci ; 49: 97-124, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33751501

RESUMEN

In this chapter, I address the concept of endophenotypes for obsessive-compulsive disorder (OCD). Endophenotypes are objective and heritable quantitative traits hypothesized to be more biologically tractable than distal clinical phenotypes. This approach has been adopted to gain a better understanding of psychiatric conditions in general. It is theorized that endophenotypes will particularly assist in clarifying both the diagnostic status and aetiological origins of complex neuropsychiatric conditions such as OCD. At the cognitive level, separable constructs of relevance for OCD have been identified. The prevailing model for OCD assumes the development of abnormalities within fronto-striatal neural circuits leading to impairment of executive functions and their neuropsychological subcomponents. Here, I address whether this model can guide towards the identification of endophenotypes for this condition and discuss possible implications.


Asunto(s)
Endofenotipos , Trastorno Obsesivo Compulsivo , Cuerpo Estriado , Función Ejecutiva , Humanos , Pruebas Neuropsicológicas , Trastorno Obsesivo Compulsivo/genética
6.
Curr Top Behav Neurosci ; 49: 125-145, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33547598

RESUMEN

Cognitive inflexibility is suggested by the hallmark symptoms of obsessive-compulsive disorder (OCD), namely the occurrence of repetitive thoughts and/or behaviours that persist despite being functionally impairing and egodystonic to the individual. As well as being implied by the top-level symptoms, cognitive inflexibility in OCD, and some related conditions, has also been objectively quantified in case-control studies using computerised cognitive tasks. This chapter begins by considering the objective measurement of different aspects of cognitive flexibility using neuropsychological paradigms, with a focus on neural and neurochemical substrates. It moves on to conduct a systematic review and meta-analysis of findings from a widely deployed flexibility task: the Intra-Dimensional/Extra-Dimensional Set-Shift Task (IDED). By pooling data from 11 studies (335 OCD patients and 311 controls), we show that Extra-Dimensional (ED) shift deficits are a robust and reproducible finding (effect size medium-large) in OCD across the literature, and that this deficit is not attributable to group differences in age or IQ. The OCD ED deficit is then discussed in terms of dysfunction of fronto-striatal pathways (as exemplified, for example, by functional connectivity data), and the putative role of different neurotransmitters. We consider evidence that impaired ED shifting constitutes a candidate vulnerability marker (or 'endophenotype') for OCD. The available literature is then surveyed as to ED findings in other obsessive-compulsive (OC) related disorders (e.g. hoarding, body-dysmorphic disorder, and trichotillomania), as well as in non-OC disorders (schizophrenia and anxiety symptoms in general). Lastly, we consider more recent, emerging developments in the quantification of compulsivity using cognitive tasks and questionnaires, as well as key directions for future research, including the need to refine compulsivity and its composite cognitive processes.


Asunto(s)
Atención , Trastorno Obsesivo Compulsivo , Ansiedad , Cognición , Cuerpo Estriado , Humanos
7.
Biol Psychiatry ; 89(10): 970-979, 2021 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-33581835

RESUMEN

BACKGROUND: The balance between goal-directed behavior and habits has been hypothesized to be biased toward the latter in individuals with cocaine use disorder (CUD), suggesting possible neurochemical changes in the putamen, which may contribute to their compulsive behavior. METHODS: We assessed habitual behavior in 48 patients with CUD and 42 healthy control participants using a contingency degradation paradigm and the Creature of Habit Scale. In a subgroup of this sample (CUD: n = 21; control participants: n = 22), we also measured glutamate and glutamine concentrations in the left putamen using ultra-high-field (7T) magnetic resonance spectroscopy. We hypothesized that increased habitual tendencies in patients with CUD would be associated with abnormal glutamatergic metabolites in the putamen. RESULTS: Compared with their non-drug-using peers, patients with CUD exhibited greater habitual tendencies during contingency degradation, which correlated with increased levels of self-reported daily habits. We further identified a significant reduction in glutamate concentration and glutamate turnover (glutamate-to-glutamine ratio) in the putamen in patients with CUD, which was significantly related to the level of self-reported daily habits. CONCLUSIONS: Patients with CUD exhibit enhanced habitual behavior, as assessed both by questionnaire and by a laboratory paradigm of contingency degradation. This automatic habitual tendency is related to a reduced glutamate turnover in the putamen, suggesting a dysregulation of habits caused by chronic cocaine use.


Asunto(s)
Trastornos Relacionados con Cocaína , Cocaína , Ácido Glutámico , Hábitos , Humanos , Imagen por Resonancia Magnética , Putamen
8.
Proc Natl Acad Sci U S A ; 117(41): 25911-25922, 2020 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-32989168

RESUMEN

A characteristic of adaptive behavior is its goal-directed nature. An ability to act in a goal-directed manner is progressively refined during development, but this refinement can be impacted by the emergence of psychiatric disorders. Disorders of compulsivity have been framed computationally as a deficit in model-based control, and have been linked also to abnormal frontostriatal connectivity. However, the developmental trajectory of model-based control, including an interplay between its maturation and an emergence of compulsivity, has not been characterized. Availing of a large sample of healthy adolescents (n = 569) aged 14 to 24 y, we show behaviorally that over the course of adolescence there is a within-person increase in model-based control, and this is more pronounced in younger participants. Using a bivariate latent change score model, we provide evidence that the presence of higher compulsivity traits is associated with an atypical profile of this developmental maturation in model-based control. Resting-state fMRI data from a subset of the behaviorally assessed subjects (n = 230) revealed that compulsivity is associated with a less pronounced change of within-subject developmental remodeling of functional connectivity, specifically between the striatum and a frontoparietal network. Thus, in an otherwise clinically healthy population sample, in early development, individual differences in compulsivity are linked to the developmental trajectory of model-based control and a remodeling of frontostriatal connectivity.


Asunto(s)
Desarrollo del Adolescente , Conducta Compulsiva/psicología , Adolescente , Adulto , Conducta Compulsiva/diagnóstico por imagen , Conducta Compulsiva/fisiopatología , Cuerpo Estriado/diagnóstico por imagen , Femenino , Objetivos , Humanos , Imagen por Resonancia Magnética , Masculino , Adulto Joven
9.
Proc Natl Acad Sci U S A ; 117(6): 3248-3253, 2020 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-31992644

RESUMEN

Adolescent changes in human brain function are not entirely understood. Here, we used multiecho functional MRI (fMRI) to measure developmental change in functional connectivity (FC) of resting-state oscillations between pairs of 330 cortical regions and 16 subcortical regions in 298 healthy adolescents scanned 520 times. Participants were aged 14 to 26 y and were scanned on 1 to 3 occasions at least 6 mo apart. We found 2 distinct modes of age-related change in FC: "conservative" and "disruptive." Conservative development was characteristic of primary cortex, which was strongly connected at 14 y and became even more connected in the period from 14 to 26 y. Disruptive development was characteristic of association cortex and subcortical regions, where connectivity was remodeled: connections that were weak at 14 y became stronger during adolescence, and connections that were strong at 14 y became weaker. These modes of development were quantified using the maturational index (MI), estimated as Spearman's correlation between edgewise baseline FC (at 14 y, [Formula: see text]) and adolescent change in FC ([Formula: see text]), at each region. Disruptive systems (with negative MI) were activated by social cognition and autobiographical memory tasks in prior fMRI data and significantly colocated with prior maps of aerobic glycolysis (AG), AG-related gene expression, postnatal cortical surface expansion, and adolescent shrinkage of cortical thickness. The presence of these 2 modes of development was robust to numerous sensitivity analyses. We conclude that human brain organization is disrupted during adolescence by remodeling of FC between association cortical and subcortical areas.


Asunto(s)
Desarrollo del Adolescente/fisiología , Encéfalo/crecimiento & desarrollo , Red Nerviosa/crecimiento & desarrollo , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Conectoma , Femenino , Movimientos de la Cabeza/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Red Nerviosa/diagnóstico por imagen , Adulto Joven
10.
Sci Rep ; 9(1): 11536, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-31395894

RESUMEN

Understanding how variations in dimensions of psychometrics, IQ and demographics relate to changes in brain connectivity during the critical developmental period of adolescence and early adulthood is a major challenge. This has particular relevance for mental health disorders where a failure to understand these links might hinder the development of better diagnostic approaches and therapeutics. Here, we investigated this question in 306 adolescents and young adults (14-24 y, 25 clinically depressed) using a multivariate statistical framework, based on canonical correlation analysis (CCA). By linking individual functional brain connectivity profiles to self-report questionnaires, IQ and demographic data we identified two distinct modes of covariation. The first mode mapped onto an externalization/internalization axis and showed a strong association with sex. The second mode mapped onto a well-being/distress axis independent of sex. Interestingly, both modes showed an association with age. Crucially, the changes in functional brain connectivity associated with changes in these phenotypes showed marked developmental effects. The findings point to a role for the default mode, frontoparietal and limbic networks in psychopathology and depression.


Asunto(s)
Encéfalo/diagnóstico por imagen , Depresión/diagnóstico por imagen , Trastornos Mentales/diagnóstico por imagen , Psicometría , Adolescente , Adulto , Encéfalo/fisiopatología , Mapeo Encefálico/métodos , Depresión/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos Mentales/fisiopatología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiopatología , Descanso/fisiología , Adulto Joven
11.
Neuron ; 102(1): 27-47, 2019 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-30946823

RESUMEN

Obsessive-compulsive disorder is a severe and disabling psychiatric disorder that presents several challenges for neuroscience. Recent advances in its genetic and developmental causation, as well as its neuropsychological basis, are reviewed. Hypotheses concerning an imbalance between goal-directed and habitual behavior together with neural correlates in cortico-striatal circuitry are evaluated and contrasted with metacognitive theories. Treatments for obsessive-compulsive disorder (OCD) tend to be of mixed efficacy but include psychological, pharmacological, and surgical approaches, the underlying mechanisms of which are still under debate. Overall, the prospects for new animal models and an integrated understanding of the pathophysiology of OCD are considered in the context of dimensional psychiatry.


Asunto(s)
Encéfalo/diagnóstico por imagen , Conducta Compulsiva/psicología , Trastorno Obsesivo Compulsivo/genética , Animales , Ansiedad/psicología , Trastornos de Ansiedad , Terapia Cognitivo-Conductual , Modelos Animales de Enfermedad , Antagonistas de Dopamina/uso terapéutico , Adicción a la Comida/psicología , Neuroimagen Funcional , Juego de Azar/psicología , Predisposición Genética a la Enfermedad , Giro del Cíngulo/cirugía , Humanos , Terapia Implosiva , Imagen por Resonancia Magnética , Procedimientos Neuroquirúrgicos , Trastorno Obsesivo Compulsivo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/psicología , Trastorno Obsesivo Compulsivo/terapia , Fenotipo , Tomografía de Emisión de Positrones , Inhibidores Selectivos de la Recaptación de Serotonina/uso terapéutico , Trastornos Relacionados con Sustancias/psicología
12.
Neuropsychologia ; 128: 282-289, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-29355648

RESUMEN

Detecting causal relationships between actions and their outcomes is fundamental to guiding goal-directed behaviour. The ventromedial prefrontal cortex (vmPFC) has been extensively implicated in computing these environmental contingencies, via animal lesion models and human neuroimaging. However, whether the vmPFC is critical for contingency learning, and whether it can occur without subjective awareness of those contingencies, has not been established. To address this, we measured response adaption to contingency and subjective awareness of action-outcome relationships in individuals with vmPFC lesions and healthy elderly subjects. We showed that in both vmPFC damage and ageing, successful behavioural adaptation to variations in action-outcome contingencies was maintained, but subjective awareness of these contingencies was reduced. These results highlight two contexts where performance and awareness have been dissociated, and show that learning response-outcome contingencies to guide behaviour can occur without subjective awareness. Preserved responding in the vmPFC group suggests that this region is not critical for computing action-outcome contingencies to guide behaviour. In contrast, our findings highlight a critical role for the vmPFC in supporting awareness, or metacognitive ability, during learning. We further advance the hypothesis that responding to changing environmental contingencies, whilst simultaneously maintaining conscious awareness of those statistical regularities, is a form of dual-tasking that is impaired in ageing due to reduced prefrontal function.


Asunto(s)
Concienciación/fisiología , Causalidad , Envejecimiento Saludable/fisiología , Corteza Prefrontal/patología , Adaptación Psicológica , Anciano , Envejecimiento/psicología , Mapeo Encefálico , Cognición , Femenino , Objetivos , Humanos , Aprendizaje , Masculino , Persona de Mediana Edad , Adulto Joven
13.
Artículo en Inglés | MEDLINE | ID: mdl-30545754

RESUMEN

BACKGROUND: In obsessive-compulsive disorder (OCD), actions persist despite being inappropriate to the situation and without relationship to the overall goal. Dysfunctional beliefs have traditionally been postulated to underlie this condition. More recently, OCD has been characterized in terms of an imbalance between the goal-directed and the habit systems. To test these competing hypotheses, we used a novel experimental task designed to test subjective action-outcome knowledge of the effectiveness of actions (i.e., instrumental contingency), together with the balance between goal-directed and habitual responding. METHODS: Twenty-seven patients with OCD and 27 healthy control subjects were tested on a novel task involving the degradation of an action-outcome contingency. Sensitivity to instrumental contingency and the extent to which explicitly reported action-outcome knowledge guided behavior were probed by measuring response rate and subjectively reported judgments. RESULTS: Patients with OCD responded more than healthy control subjects in situations in which an action was less causally related to obtaining an outcome. However, patients showed intact explicit action-outcome knowledge, as assessed by self-report. In patients, the relationship between causality judgment and responding was altered; therefore, their actions were dissociated from explicit action-outcome knowledge. CONCLUSIONS: These findings indicate reduced sensitivity to instrumental contingency in OCD, reinforcing the notion of a deficient goal-directed system in this disorder. By showing a dissociation between subjectively reported action-outcome knowledge and behavior, the data provide experimental evidence for the ego-dystonic nature of OCD.


Asunto(s)
Objetivos , Hábitos , Juicio , Aprendizaje , Trastorno Obsesivo Compulsivo/psicología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Desempeño Psicomotor
14.
Artículo en Inglés | MEDLINE | ID: mdl-29914992

RESUMEN

We rarely use abstract and concrete concepts in isolation but rather embedded within a linguistic context. To examine the modulatory impact of the linguistic context on conceptual processing, we isolated the case of sentential negation polarity, in which an interaction occurs between the syntactic operator not and conceptual information in the negation's scope. Previous studies suggested that sentential negation of concrete action-related concepts modulates activation in the fronto-parieto-temporal action representation network. In this functional magnetic resonance imaging study, we examined the influence of negation on a wider spectrum of meanings, by factorially manipulating sentence polarity (affirmative, negative) and fine-grained abstract (mental state, emotion, mathematics) and concrete (related to mouth, hand, leg actions) conceptual categories. We adopted a multivariate pattern analysis approach, and tested the accuracy of a machine learning classifier in discriminating brain activation patterns associated to the factorial manipulation. Searchlight analysis was used to localize the discriminating patterns. Overall, the neural processing of affirmative and negative sentences with either an abstract or concrete content could be accurately predicted by means of multivariate classification. We suggest that sentential negation polarity modulates brain activation in distributed representational semantic networks, through the functional mediation of syntactic and cognitive control systems.This article is part of the theme issue 'Varieties of abstract concepts: development, use and representation in the brain'.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Comprensión , Formación de Concepto , Semántica , Adolescente , Adulto , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Italia , Imagen por Resonancia Magnética , Masculino , Análisis Multivariante , Pesimismo , Adulto Joven
15.
Int J Neuropsychopharmacol ; 21(1): 42-58, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29036632

RESUMEN

Compulsions are repetitive, stereotyped thoughts and behaviors designed to reduce harm. Growing evidence suggests that the neurocognitive mechanisms mediating behavioral inhibition (motor inhibition, cognitive inflexibility) reversal learning and habit formation (shift from goal-directed to habitual responding) contribute toward compulsive activity in a broad range of disorders. In obsessive compulsive disorder, distributed network perturbation appears focused around the prefrontal cortex, caudate, putamen, and associated neuro-circuitry. Obsessive compulsive disorder-related attentional set-shifting deficits correlated with reduced resting state functional connectivity between the dorsal caudate and the ventrolateral prefrontal cortex on neuroimaging. In contrast, experimental provocation of obsessive compulsive disorder symptoms reduced neural activation in brain regions implicated in goal-directed behavioral control (ventromedial prefrontal cortex, caudate) with concordant increased activation in regions implicated in habit learning (presupplementary motor area, putamen). The ventromedial prefrontal cortex plays a multifaceted role, integrating affective evaluative processes, flexible behavior, and fear learning. Findings from a neuroimaging study of Pavlovian fear reversal, in which obsessive compulsive disorder patients failed to flexibly update fear responses despite normal initial fear conditioning, suggest there is an absence of ventromedial prefrontal cortex safety signaling in obsessive compulsive disorder, which potentially undermines explicit contingency knowledge and may help to explain the link between cognitive inflexibility, fear, and anxiety processing in compulsive disorders such as obsessive compulsive disorder.


Asunto(s)
Mapeo Encefálico , Trastornos del Conocimiento/etiología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Vías Nerviosas/patología , Trastorno Obsesivo Compulsivo , Humanos , Neuroimagen , Trastorno Obsesivo Compulsivo/complicaciones , Trastorno Obsesivo Compulsivo/diagnóstico por imagen , Trastorno Obsesivo Compulsivo/patología , Trastorno Obsesivo Compulsivo/terapia
16.
Artículo en Inglés | MEDLINE | ID: mdl-29167834

RESUMEN

BACKGROUND: The symptoms of obsessive-compulsive disorder (OCD) have been postulated to result from impaired executive functioning and excessive habit formation at the expense of goal-directed control and have been objectively demonstrated using neuropsychological tests in such patients. This study tested whether there is functional hypoactivation as well as dysconnectivity of discrete frontostriatal pathways during goal-directed planning in patients with OCD and in their unaffected first-degree relatives. METHODS: In total, 21 comorbidity-free patients with OCD, 19 clinically asymptomatic first-degree relatives of these patients, and 20 control participants were tested on a functional magnetic resonance optimized version of the Tower of London task. Group differences in brain activation during goal-directed planning were measured together with associated frontostriatal functional connectivity. RESULTS: Patients with OCD and their clinically asymptomatic relatives manifested hypoactivation of the right dorsolateral prefrontal cortex during goal-directed planning coupled with reduced functional connectivity between this cortical region and the basal ganglia (putamen). CONCLUSIONS: Hypoactivation of cortical regions associated with goal-directed planning and associated frontostriatal dysconnectivity represent a candidate endophenotype for OCD. These findings accord with abnormalities in neural networks supporting the balance between goal-directed and habitual behavior, with implications for recent neuropsychological theories of OCD and the major neurobiological model for this disorder.

17.
Neuron ; 96(2): 348-354.e4, 2017 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-28965997

RESUMEN

Confidence and actions are normally tightly interwoven-if I am sure that it is going to rain, I will take an umbrella-therefore, it is difficult to understand their interplay. Stimulated by the ego-dystonic nature of obsessive-compulsive disorder (OCD), where compulsive actions are recognized as disproportionate, we hypothesized that action and confidence might be independently updated during learning. Participants completed a predictive-inference task designed to identify how action and confidence evolve in response to surprising changes in the environment. While OCD patients (like controls) correctly updated their confidence according to changes in the environment, their actions (unlike those of controls) mostly disregarded this knowledge. Therefore, OCD patients develop an accurate, internal model of the environment but fail to use it to guide behavior. Results demonstrated a novel dissociation between confidence and action, suggesting a cognitive architecture whereby confidence estimates can accurately track the statistic of the environment independently from performance.


Asunto(s)
Toma de Decisiones/fisiología , Aprendizaje/fisiología , Trastorno Obsesivo Compulsivo/psicología , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Adulto , Conducta Compulsiva/fisiopatología , Conducta Compulsiva/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastorno Obsesivo Compulsivo/fisiopatología
18.
Neuroimage ; 155: 169-176, 2017 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-28438665

RESUMEN

An Intention Processing Network (IPN), involving the medial prefrontal cortex, precuneus, bilateral posterior superior temporal sulcus, and temporoparietal junctions, plays a fundamental role in comprehending intentions underlying action goals. In a previous fMRI study, we showed that, depending on the linguistic or extralinguistic (gestural) modality used to convey the intention, the IPN is complemented by activation of additional brain areas, reflecting distinct modality-specific input gateways to the IPN. These areas involve, for the linguistic modality, the left inferior frontal gyrus (LIFG), and for the extralinguistic modality, the right inferior frontal gyrus (RIFG). Here, we tested the modality-specific gateway hypothesis, by using DCM to measure inter-regional functional integration dynamics between the IPN and LIFG/RIFG gateways. We found strong evidence of a well-defined effective connectivity architecture mediating the functional integration between the IPN and the inferior frontal cortices. The connectivity dynamics indicate a modality-specific propagation of stimulus information from LIFG to IPN for the linguistic modality, and from RIFG to IPN for the extralinguistic modality. Thus, we suggest a functional model in which the modality-specific gateways mediate the structural and semantic decoding of the stimuli, and allow for the modality-specific communicative information to be integrated in Theory of Mind inferences elaborated through the IPN.


Asunto(s)
Encéfalo/fisiología , Comunicación , Intención , Modelos Neurológicos , Teoría de la Mente/fisiología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/fisiología , Adulto Joven
19.
World J Biol Psychiatry ; 18(3): 162-214, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27419272

RESUMEN

OBJECTIVE: Biomarkers are defined as anatomical, biochemical or physiological traits that are specific to certain disorders or syndromes. The objective of this paper is to summarise the current knowledge of biomarkers for anxiety disorders, obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD). METHODS: Findings in biomarker research were reviewed by a task force of international experts in the field, consisting of members of the World Federation of Societies for Biological Psychiatry Task Force on Biological Markers and of the European College of Neuropsychopharmacology Anxiety Disorders Research Network. RESULTS: The present article (Part II) summarises findings on potential biomarkers in neurochemistry (neurotransmitters such as serotonin, norepinephrine, dopamine or GABA, neuropeptides such as cholecystokinin, neurokinins, atrial natriuretic peptide, or oxytocin, the HPA axis, neurotrophic factors such as NGF and BDNF, immunology and CO2 hypersensitivity), neurophysiology (EEG, heart rate variability) and neurocognition. The accompanying paper (Part I) focuses on neuroimaging and genetics. CONCLUSIONS: Although at present, none of the putative biomarkers is sufficient and specific as a diagnostic tool, an abundance of high quality research has accumulated that should improve our understanding of the neurobiological causes of anxiety disorders, OCD and PTSD.


Asunto(s)
Trastornos de Ansiedad/diagnóstico , Biomarcadores , Trastorno Obsesivo Compulsivo/diagnóstico , Trastornos por Estrés Postraumático/diagnóstico , Comités Consultivos , Psiquiatría Biológica , Consenso , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Sociedades Médicas
20.
Biol Psychiatry ; 81(8): 708-717, 2017 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-27769568

RESUMEN

BACKGROUND: A recent hypothesis has suggested that core deficits in goal-directed behavior in obsessive-compulsive disorder (OCD) are caused by impaired frontostriatal function. We tested this hypothesis in OCD patients and control subjects by relating measures of goal-directed planning and cognitive flexibility to underlying resting-state functional connectivity. METHODS: Multiecho resting-state acquisition, combined with micromovement correction by blood oxygen level-dependent sensitive independent component analysis, was used to obtain in vivo measures of functional connectivity in 44 OCD patients and 43 healthy comparison subjects. We measured cognitive flexibility (attentional set-shifting) and goal-directed performance (planning of sequential response sequences) by means of well-validated, standardized behavioral cognitive paradigms. Functional connectivity strength of striatal seed regions was related to cognitive flexibility and goal-directed performance. To gain insights into fundamental network alterations, graph theoretical models of brain networks were derived. RESULTS: Reduced functional connectivity between the caudate and the ventrolateral prefrontal cortex was selectively associated with reduced cognitive flexibility. In contrast, goal-directed performance was selectively related to reduced functional connectivity between the putamen and the dorsolateral prefrontal cortex in OCD patients, as well as to symptom severity. Whole-brain data-driven graph theoretical analysis disclosed that striatal regions constitute a cohesive module of the community structure of the functional connectome in OCD patients as nodes within the basal ganglia and cerebellum were more strongly connected to one another than in healthy control subjects. CONCLUSIONS: These data extend major neuropsychological models of OCD by providing a direct link between intrinsically abnormal functional connectivity within dissociable frontostriatal circuits and those cognitive processes underlying OCD symptoms.


Asunto(s)
Cognición/fisiología , Cuerpo Estriado/fisiopatología , Función Ejecutiva/fisiología , Objetivos , Trastorno Obsesivo Compulsivo/fisiopatología , Corteza Prefrontal/fisiopatología , Adulto , Atención/fisiología , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Vías Nerviosas/fisiopatología , Índice de Severidad de la Enfermedad
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