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1.
BJPsych Open ; 9(5): e173, 2023 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-37781848

RESUMEN

BACKGROUND: The Autism Spectrum Quotient is a popular autism screening tool recommended for identifying potential cases of autism. However, many women with autism demonstrate a different presentation of traits to those currently captured by screening measures and assessment methods, such as the Autism Spectrum Quotient. AIMS: Different models of the Autism Spectrum Quotient have been proposed in the literature, utilising different items from the original 50-item scale. Within good-fitting models, the current study aimed to explore whether these items assess autistic traits similarly across men and women. METHOD: Seventeen Autism Spectrum Quotient models were identified from the literature. Using the responses of a large sample of adults from the UK general population (5246 women, 1830 men), confirmatory factor analysis was used to evaluate the fit of each model. Measurement invariance with respect to gender, adjusting for age, was explored in the 11 model frameworks that were found to have satisfactory fit to our data. RESULTS: It emerged that only two items were gender invariant (non-biased), whereas for the remaining items, the probability of endorsement was influenced by gender. In particular, women had a higher probability of endorsing items relating to social skills and communication. CONCLUSIONS: If the items of the Autism Spectrum Quotient indeed reflect autism-related traits, those items should be rephrased to ensure they do not present a gender-related bias. This is vital for ensuring more timely diagnoses and support for all people with autism.

3.
Cereb Cortex ; 33(9): 5436-5446, 2023 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-36368894

RESUMEN

Behavioral and cognitive flexibility allow adaptation to a changing environment. Most tasks used to investigate flexibility require switching reactively in response to deterministic task-response rules. In daily life, flexibility often involves a volitional decision to change behavior. This can be instigated by environmental signals, but these are frequently unreliable. We report results from a novel "change your mind" task, which assesses volitional switching under uncertainty without the need for rule-based learning. Participants completed a two-alternative choice task, and following spurious feedback, were presented with the same stimulus again. Subjects had the opportunity to repeat or change their response. Forty healthy participants completed the task while undergoing a functional magnetic resonance imaging scan. Participants predominantly repeated their choice but changed more when their first response was incorrect or when the feedback was negative. Greater activations for changing were found in the inferior frontal junction, anterior insula (AI), anterior cingulate, and dorsolateral prefrontal cortex. Changing responses were also accompanied by reduced connectivity from the AI and orbitofrontal cortices to the occipital cortex. Using multivariate pattern analysis of brain activity, we predicted with 77% reliability whether participants would change their mind. These findings extend our understanding of cognitive flexibility in daily life by assessing volitional decision-making.


Asunto(s)
Encéfalo , Conducta de Elección , Cognición , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Algoritmos , Encéfalo/citología , Encéfalo/fisiología , Mapeo Encefálico , Conducta de Elección/fisiología , Cognición/fisiología , Voluntarios Sanos , Imagen por Resonancia Magnética , Vías Nerviosas
4.
J Autism Dev Disord ; 53(8): 3118-3132, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35593995

RESUMEN

Female Phenotype Theory (FPT) suggests that autistic women often present with less obvious social impairments than autistic men. We examined the possibility of an exaggerated female phenotype among undiagnosed but probably autistic women. In two nationwide online surveys, we compared self-reported social functioning and mental health between diagnosed autistic women and women without diagnosis who scored ≥ 32 on the Autism Quotient. Compared to diagnosed autistic women, probably autistic women had higher empathy and general social functioning, and were more likely to have received a diagnosis of Borderline Personality Disorder. Autistic women had typically received more mental health diagnoses prior to their ASC diagnosis than autistic men. These findings shed light on the history of misdiagnosis experienced by many autistic women.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Humanos , Femenino , Trastorno Autístico/diagnóstico , Trastorno Autístico/psicología , Trastorno del Espectro Autista/diagnóstico , Trastorno del Espectro Autista/psicología , Interacción Social , Salud Mental , Empatía
5.
J Autism Dev Disord ; 52(8): 3413-3426, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34342806

RESUMEN

Camouflaging of autistic traits may make autism harder to diagnose. The current study evaluated the relations between camouflaging intent, first impressions, and age of autism diagnosis. Participants comprised autistic and non-autistic adults (n = 80, 50% female) who completed the Camouflaging of Autistic Traits Questionnaire. They were later video-recorded having a conversation with a person unaware of their diagnostic status. Ten-second clips from half these videos were later shown to 127 non-autistic peers, who rated their first impressions of each participant. Results showed that autistic participants were rated more poorly on first impressions, males were rated less favourably than females, and male raters were particularly harsh in their evaluations of autistic males. Camouflaging intent did not predict first impressions but better first impressions were linked with a later age of diagnosis.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Adulto , Trastorno Autístico/diagnóstico , Femenino , Humanos , Intención , Masculino , Grupo Paritario , Encuestas y Cuestionarios
6.
Artículo en Inglés | MEDLINE | ID: mdl-34508901

RESUMEN

BACKGROUND: Impaired response inhibition in individuals with cocaine use disorder (CUD) is hypothesized to depend on deficient noradrenergic signaling in corticostriatal networks. Remediation of noradrenergic neurotransmission with selective norepinephrine reuptake inhibitors such as atomoxetine may therefore have clinical utility to improve response inhibitory control in CUD. METHODS: We carried out a randomized, double-blind, placebo-controlled, crossover study with 26 participants with CUD and 28 control volunteers investigating the neural substrates of stop-signal inhibitory control. The effects of a single dose of atomoxetine (40 mg) were compared with placebo on stop-signal reaction time performance and functional network connectivity using dynamic causal modeling. RESULTS: We found that atomoxetine speeded Go response times in both control participants and those with CUD. Improvements in stopping efficiency on atomoxetine were conditional on baseline (placebo) stopping performance and were directly associated with increased inferior frontal gyrus activation. Further, stopping performance, task-based brain activation, and effective connectivity were similar in the 2 groups. Dynamic causal modeling of effective connectivity of multiple prefrontal and basal ganglia regions replicated and extended previous models of network function underlying inhibitory control to CUD and control volunteers and showed subtle effects of atomoxetine on prefrontal-basal ganglia interactions. CONCLUSIONS: These findings demonstrate that atomoxetine improves response inhibition in a baseline-dependent manner in control participants and in those with CUD. Our results emphasize inferior frontal cortex function as a future treatment target owing to its key role in improving response inhibition in CUD.


Asunto(s)
Inhibidores de Captación Adrenérgica , Cocaína , Humanos , Clorhidrato de Atomoxetina/farmacología , Clorhidrato de Atomoxetina/uso terapéutico , Inhibidores de Captación Adrenérgica/farmacología , Inhibidores de Captación Adrenérgica/uso terapéutico , Voluntarios Sanos , Estudios Cruzados , Inhibición Psicológica , Corteza Prefrontal , Cocaína/farmacología
7.
J Psychiatr Res ; 145: 167-174, 2021 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-34923357

RESUMEN

Hoarding Disorder (HD) is under recognised and under-treated. Though HD develops by early adulthood, patients present only later in life, resulting in research based largely on samples of predominantly older females. Whilst formerly associated with Obsessive-Compulsive Disorder (OCD), it is now recognised that individuals with HD often have inattention symptoms reminiscent of Attention Deficit/Hyperactivity Disorder (ADHD). Here, we investigated HD in adults with ADHD. Patients in an ADHD clinic (n = 88) reported on ADHD, HD and OCD-related symptoms, and compared with age, gender and education matched controls (n = 90). Findings were assessed independently in an online UK sample to verify replication using a dimensional approach (n = 220). Clinically significant hoarding symptoms were found in ∼20% versus 2% of ADHD and control groups, respectively, with those with hoarding being on average in their thirties and with approximately half being male. Greater hoarding severity was noted even in the remaining patients compared with controls (d = 0.89). Inattention was the only significant statistical predictor of hoarding severity in patients. Similarly, inattention, alongside depression and anxiety were the greatest predictors of hoarding in the independent sample where 3.2% identified as having clinically significant hoarding. Patients with ADHD had a high frequency of hoarding symptoms, which were specifically linked to inattention. HD should be routinely assessed in individuals with ADHD, as they do not typically disclose associated difficulties, despite these potentially leading to impaired everyday functioning. Research in HD should also investigate adults with ADHD, who are younger and with a greater prevalence of males than typical HD samples.

8.
Brain Sci ; 11(8)2021 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-34439598

RESUMEN

Response inhibition, whether reactive or proactive, is mostly investigated in a narrow cognitive framework. We argue that it be viewed within a broader frame than the action being inhibited, i.e., in the context of emotion and motivation of the individual at large. This is particularly important in the clinical domain, where the motivational strength of an action can be driven by threat avoidance or reward seeking. The cognitive response inhibition literature has focused on stopping reactively with responses in anticipation of clearly delineated external signals, or proactively in limited contexts, largely independent of clinical phenomena. Moreover, the focus has often been on stopping efficiency and its correlates rather than on inhibition failures. Currently, the cognitive and clinical perspectives are incommensurable. A broader context may explain the apparent paradox where individuals with disorders characterised by maladaptive action control have difficulty inhibiting their actions only in specific circumstances. Using Obsessive Compulsive Disorder as a case study, clinical theorising has focused largely on compulsions as failures of inhibition in relation to specific internal or external triggers. We propose that the concept of action tendencies may constitute a useful common denominator bridging research into motor, emotional, motivational, and contextual aspects of action control failure. The success of action control may depend on the interaction between the strength of action tendencies, the ability to withhold urges, and contextual factors.

9.
CNS Spectr ; 26(5): 457-458, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-32600488

RESUMEN

In the last 20 years, technology is increasingly integrated into daily life. Daily interactions with smart devices have become routine with much of our lives taking place in a digital environment. It is therefore not surprising that the manifestations of psychiatric disorders including Obsessive-Compulsive Disorder have changed in recent years reflecting this reality. Clinicians should be aware of the potential impact of such changes when considering symptom presentation and diagnosis.


Asunto(s)
Trastorno de Adicción a Internet/psicología , Trastorno Obsesivo Compulsivo/psicología , Humanos
10.
Aust N Z J Psychiatry ; 54(7): 719-731, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32364439

RESUMEN

BACKGROUND: The Research Domain Criteria seeks to bridge knowledge from neuroscience with clinical practice by promoting research into valid neurocognitive phenotypes and dimensions, irrespective of symptoms and diagnoses as currently conceptualized. While the Research Domain Criteria offers a vision of future research and practice, its 39 functional constructs need refinement to better target new phenotyping efforts. This study aimed to determine which Research Domain Criteria constructs are most relevant to understanding obsessive-compulsive and related disorders, based on a consensus between experts in the field of obsessive-compulsive and related disorders. METHODS: Based on a modified Delphi method, 46 experts were recruited from Australia, Africa, Asia, Europe and the Americas. Over three rounds, experts had the opportunity to review their opinion in light of feedback from the previous round, which included how their response compared to other experts and a summary of comments given. RESULTS: Thirty-four experts completed round one, of whom 28 (82%) completed round two and 24 (71%) completed round three. At the final round, four constructs were endorsed by ⩾75% of experts as 'primary constructs' and therefore central to understanding obsessive-compulsive and related disorders. Of these constructs, one came from the Positive Valence System (Habit), two from the Cognitive Control System (Response Selection/Inhibition and Performance Monitoring) and the final construct was an additional item suggested by experts (Compulsivity). CONCLUSION: This study identified four Research Domain Criteria constructs that, according to experts, cut across different obsessive-compulsive and related disorders. These constructs represent key areas for future investigation, and may have potential implications for clinical practice in terms of diagnostic processes and therapeutic management of obsessive-compulsive and related disorders.


Asunto(s)
Consenso , Técnica Delphi , Internacionalidad , Trastorno Obsesivo Compulsivo/diagnóstico , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
11.
Hum Brain Mapp ; 41(8): 2216-2228, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32150321

RESUMEN

Adequate control of impulsive urges to act is demanded in everyday life but is impaired in neuropsychiatric conditions such as stimulant use disorder. Despite intensive research it remains unclear whether failures in impulse control are caused by impaired suppression of behavior or by the over invigoration of behavior by stimuli associated with salient incentives such as drugs, food, and money. We investigated failures in impulse control using functional magnetic resonance imaging (fMRI) to map the neural correlates of premature (impulsive) responses during the anticipation phase of the Monetary Incentive Delay (MID) task in healthy controls (HC), stimulant-dependent individuals (SDIs), and their unaffected first-degree siblings (SIB). We combined task-based fMRI analyses with dynamic causal modeling to show that failures of impulse control were associated with interactions between cingulo-opercular and dorsal striatal networks regardless of group status and incentive type. We further report that group-specific incentive salience plays a critical role in modulating impulsivity in SDIs since drug-related incentives specifically increased premature responding and shifted task modulation away from the dorsal striatal network to the cingulo-opercular network. Our findings thus indicate that impulsive actions are elicited by salient personally-relevant incentive stimuli and those such slips of action recruit a distinct fronto-striatal network.


Asunto(s)
Mapeo Encefálico , Giro del Cíngulo/fisiología , Conducta Impulsiva/fisiología , Motivación/fisiología , Neostriado/fisiología , Red Nerviosa/fisiología , Personalidad/fisiología , Corteza Prefrontal/fisiología , Adulto , Anticipación Psicológica/fisiología , Estimulantes del Sistema Nervioso Central , Femenino , Giro del Cíngulo/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Neostriado/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagen , Corteza Prefrontal/diagnóstico por imagen , Hermanos , Trastornos Relacionados con Sustancias/diagnóstico por imagen , Trastornos Relacionados con Sustancias/fisiopatología , Adulto Joven
12.
PLoS One ; 15(1): e0225970, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31940308

RESUMEN

High levels of intolerance of uncertainty (IU) could contribute to abnormal decision making in uncertain situations. Patients with Obsessive Compulsive Disorder (OCD) often report high IU, indecisiveness and the need to seek greater certainty before making decisions. The Beads task is a commonly used task assessing the degree of information gathering prior to making a decision and so would be predicted to show impairments in OCD patients. Results to date have found mixed support for this, possibility due to methodological issues. Here, a group of OCD patients (n = 50) with no comorbidities was compared with age, gender, and verbal-IQ matched controls (n = 50) on the most commonly used version of the Beads task. An independent sample of healthy volunteers with high versus low OC symptoms, and high versus low IU were also assessed (n = 125). There was no evidence that patients with OCD differed from control volunteers in the degree of information gathering prior to making a decision. Medication status and age did not appear to mediate performance. Similarly, there were no association in healthy volunteers between task performance and OC or IU characteristics. Additional measures examining the degree of certainty initially showed support for greater uncertainty in patients, but this was due to deviations from task instructions in a subset of patients. We conclude that despite the large sample size and good matching between groups, the Beads task in its most widely used form is not a useful measure of IU or of information gathering in OCD. The results argue against a robust behavioural difference in OCD when compared to controls. Recommendations for future studies employing the task are discussed.


Asunto(s)
Toma de Decisiones , Trastorno Obsesivo Compulsivo/psicología , Incertidumbre , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas
13.
Elife ; 82019 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-31033438

RESUMEN

Response inhibition is essential for navigating everyday life. Its derailment is considered integral to numerous neurological and psychiatric disorders, and more generally, to a wide range of behavioral and health problems. Response-inhibition efficiency furthermore correlates with treatment outcome in some of these conditions. The stop-signal task is an essential tool to determine how quickly response inhibition is implemented. Despite its apparent simplicity, there are many features (ranging from task design to data analysis) that vary across studies in ways that can easily compromise the validity of the obtained results. Our goal is to facilitate a more accurate use of the stop-signal task. To this end, we provide 12 easy-to-implement consensus recommendations and point out the problems that can arise when they are not followed. Furthermore, we provide user-friendly open-source resources intended to inform statistical-power considerations, facilitate the correct implementation of the task, and assist in proper data analysis.


Asunto(s)
Consenso , Conducta Impulsiva/fisiología , Inhibición Psicológica , Desempeño Psicomotor/fisiología , Animales , Toma de Decisiones , Función Ejecutiva/fisiología , Humanos , Modelos Animales , Modelos Psicológicos , Pruebas Neuropsicológicas , Tiempo de Reacción
14.
Q J Exp Psychol (Hove) ; 71(10): 2052-2069, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29359639

RESUMEN

Excessive checking is reported in non-clinical populations and is a pervasive symptom in obsessive compulsive disorder (OCD). We implemented a free-operant task in humans, previously used in rats, wherein participants can "check" to reduce uncertainty. Participants can press an observing key to ascertain which of two main keys will, if pressed, currently lead to rewards. Over a series of experiments, we found that punishment robustly increased observing in non-clinical participants and that observing persisted long after punishment was removed. Moreover, participants appeared insensitive to the initial costs of checking, and a threefold increase in the effort required to observe served to deter participants only to a limited degree. We also assessed observing in OCD patients with no known comorbidities. The patients observed more than control participants and were abnormally insensitive to the introduction of punishment. These findings support the translational value of the task, with similar behaviours in humans and rodents. This paradigm may serve as a unifying platform, promoting interaction between different approaches to analyse adaptive and maladaptive certainty seeking behaviours. Specifically, we demonstrate how seemingly disparate theoretical and empirical approaches can be reconciled synergistically to promote a combined behavioural and cognitive account of certainty seeking.


Asunto(s)
Motivación/fisiología , Observación , Trastorno Obsesivo Compulsivo/fisiopatología , Trastorno Obsesivo Compulsivo/psicología , Adulto , Análisis de Varianza , Ansiedad/etiología , Femenino , Humanos , Masculino , Estimulación Luminosa , Desempeño Psicomotor/fisiología , Castigo , Recompensa , Autoinforme , Adulto Joven
15.
Psychol Med ; 48(11): 1900-1908, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29353562

RESUMEN

BACKGROUND: Youths with obsessive-compulsive disorder (OCD) experience severe distress and impaired functioning at school and at home. Critical cognitive domains for daily functioning and academic success are learning, memory, cognitive flexibility and goal-directed behavioural control. Performance in these important domains among teenagers with OCD was therefore investigated in this study. METHODS: A total of 36 youths with OCD and 36 healthy comparison subjects completed two memory tasks: Pattern Recognition Memory (PRM) and Paired Associates Learning (PAL); as well as the Intra-Extra Dimensional Set Shift (IED) task to quantitatively gauge learning as well as cognitive flexibility. A subset of 30 participants of each group also completed a Differential-Outcome Effect (DOE) task followed by a Slips-of-Action Task, designed to assess the balance of goal-directed and habitual behavioural control. RESULTS: Adolescent OCD patients showed a significant learning and memory impairment. Compared with healthy comparison subjects, they made more errors on PRM and PAL and in the first stages of IED involving discrimination and reversal learning. Patients were also slower to learn about contingencies in the DOE task and were less sensitive to outcome devaluation, suggesting an impairment in goal-directed control. CONCLUSIONS: This study advances the characterization of juvenile OCD. Patients demonstrated impairments in all learning and memory tasks. We also provide the first experimental evidence of impaired goal-directed control and lack of cognitive plasticity early in the development of OCD. The extent to which the impairments in these cognitive domains impact academic performance and symptom development warrants further investigation.


Asunto(s)
Disfunción Cognitiva/fisiopatología , Función Ejecutiva/fisiología , Aprendizaje/fisiología , Trastorno Obsesivo Compulsivo/fisiopatología , Adolescente , Adulto , Aprendizaje por Asociación/fisiología , Niño , Femenino , Humanos , Masculino , Reconocimiento Visual de Modelos/fisiología , Reconocimiento en Psicología/fisiología , Aprendizaje Inverso/fisiología , Adulto Joven
16.
Lancet Psychiatry ; 2(4): 357-62, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26360089

RESUMEN

Neuropsychiatric disorders typically manifest as problems with attentional biases, aberrant learning, dysfunctional reward systems, and an absence of top-down cognitive control by the prefrontal cortex. In view of the cost of common mental health disorders, in terms of distress to the individual and family in addition to the financial cost to society and governments, new developments for treatments that address cognitive dysfunction should be a priority so that all members of society can flourish. Cognitive enhancing drugs, such as cholinesterase inhibitors and methylphenidate, are used as treatments for the cognitive symptoms of Alzheimer's disease and attention deficit hyperactivity disorder. However, these drugs and others, including modafinil, are being increasingly used by healthy people for enhancement purposes. Importantly for ethical and safety reasons, the drivers for this increasing lifestyle use of so-called smart drugs by healthy people should be considered and discussions must occur about how to ensure present and future pharmacological cognitive enhancers are used for the benefit of society.


Asunto(s)
Compuestos de Bencidrilo/uso terapéutico , Inhibidores de la Colinesterasa/uso terapéutico , Trastornos del Conocimiento/tratamiento farmacológico , Cognición/efectos de los fármacos , Metilfenidato/uso terapéutico , Nootrópicos/uso terapéutico , Enfermedad de Alzheimer/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad , Compuestos de Bencidrilo/efectos adversos , Compuestos de Bencidrilo/farmacología , Inhibidores de la Colinesterasa/efectos adversos , Inhibidores de la Colinesterasa/farmacología , Humanos , Estilo de Vida , Metilfenidato/efectos adversos , Metilfenidato/farmacología , Modafinilo , Nootrópicos/efectos adversos , Nootrópicos/farmacología
17.
Brain Res ; 1628(Pt A): 117-29, 2015 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-25218611

RESUMEN

Disruptions to inhibitory control are believed to contribute to multiple aspects of drug abuse, from preexisting vulnerability in at-risk individuals, through escalation to dependence, to promotion of relapse in chronic users. Paradigms investigating the suppression of actions have been investigated in animal and human research on drug addiction. Rodent research has focused largely on impulsive behaviors, often gauged by premature responding, as a viable model highlighting the relevant role of dopamine and other neurotransmitters primarily in the striatum. Human research on action inhibition in stimulant dependence has highlighted impaired performance and largely prefrontal cortical abnormalities as part of a broader pattern of cognitive abnormalities. Animal and human research implicate inhibitory difficulties mediated by fronto-striatal circuitry both preceding and as a result of excessive stimulus use. In this regard, response-inhibition has proven a useful cognitive function to gauge the integrity of fronto-striatal systems and their role in contributing to impulsive and compulsive features of drug dependence.


Asunto(s)
Conducta Adictiva/fisiopatología , Cuerpo Estriado/fisiopatología , Lóbulo Frontal/fisiopatología , Inhibición Psicológica , Trastornos Relacionados con Sustancias/fisiopatología , Animales , Humanos , Vías Nerviosas/fisiopatología , Trastornos Relacionados con Sustancias/psicología
18.
Am J Psychiatry ; 172(3): 284-93, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25526600

RESUMEN

OBJECTIVE: The purpose of this study was to determine the neural correlates of excessive habit formation in obsessive-compulsive disorder (OCD). The authors aimed to test for neurobiological convergence with the known pathophysiology of OCD and to infer, based on abnormalities in brain activation, whether these habits arise from dysfunction in the goal-directed or habit system. METHOD: Thirty-seven OCD patients and 33 healthy comparison subjects learned to avoid shocks while undergoing a functional MRI scan. Following four blocks of training, the authors tested whether the avoidance response had become a habit by removing the threat of shock and measuring continued avoidance. Task-related differences in brain activity in three regions of interest (the caudate, the putamen, and the medial orbitofrontal cortex) were tested at a statistical threshold set at <0.05 (family-wise-error corrected). RESULTS: Excessive habit formation in OCD patients, which was associated with hyperactivation in the caudate, was observed. Activation in this region was also associated with subjective ratings of increased urge to perform habits. The OCD group, as a whole, showed hyperactivation in the medial orbitofrontal cortex during the acquisition of avoidance; however, this did not relate directly to habit formation. CONCLUSIONS: OCD patients exhibited excessive habits that were associated with hyperactivation in a key region implicated in the pathophysiology of OCD, the caudate nucleus. Previous studies indicate that this region is important for goal-directed behavior, suggesting that habit-forming biases in OCD may be a result of impairments in this system, rather than differences in the buildup of stimulus-response habits themselves.


Asunto(s)
Reacción de Prevención/fisiología , Núcleo Caudado , Trastorno Obsesivo Compulsivo , Corteza Prefrontal , Adulto , Núcleo Caudado/patología , Núcleo Caudado/fisiopatología , Femenino , Neuroimagen Funcional/métodos , Hábitos , Humanos , Masculino , Trastorno Obsesivo Compulsivo/patología , Trastorno Obsesivo Compulsivo/fisiopatología , Trastorno Obsesivo Compulsivo/psicología , Corteza Prefrontal/patología , Corteza Prefrontal/fisiopatología , Psicopatología , Putamen/patología , Putamen/fisiopatología , Proyectos de Investigación
19.
Hum Brain Mapp ; 35(10): 5141-52, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24819224

RESUMEN

Adult ADHD has been linked to impaired motor response inhibition and reduced associated activation in the right inferior frontal cortex (IFC). However, it is unclear whether abnormal inferior frontal activation in adult ADHD is specifically related to a response inhibition deficit or reflects a more general deficit in attentional processing. Using functional magnetic resonance imaging, we tested a group of 19 ADHD patients with no comorbidities and a group of 19 healthy control volunteers on a modified go/no-go task that has been shown previously to distinguish between cortical responses related to response inhibition and attentional shifting. Relative to the healthy controls, ADHD patients showed increased commission errors and reduced activation in inferior frontal cortex during response inhibition. Crucially, this reduced activation was observed when controlling for attentional processing, suggesting that hypoactivation in right IFC in ADHD is specifically related to impaired response inhibition. The results are consistent with the notion of a selective neurocognitive deficit in response inhibition in adult ADHD associated with abnormal functional activation in the prefrontal cortex, whilst ruling out likely group differences in attentional orienting, arousal and motivation.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/patología , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Lóbulo Frontal/fisiopatología , Lateralidad Funcional/fisiología , Inhibición Psicológica , Adulto , Análisis de Varianza , Mapeo Encefálico , Toma de Decisiones , Imagen Eco-Planar , Femenino , Lóbulo Frontal/irrigación sanguínea , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Oxígeno/sangre , Factores Sexuales , Adulto Joven
20.
Front Psychol ; 5: 204, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24659974

RESUMEN

There is disagreement regarding the role of perceived control in obsessive-compulsive disorder (OCD). The present study used a traditional illusion of control paradigm (Alloy and Abramson, 1979) to empirically test control estimation in OCD. Twenty-six OCD patients and 26 matched comparison subjects completed an illusion of control task wherein their goal was to attempt to exert control over a light bulb. The density of reinforcement (high, low) and the valence of trials (gain, loss) were experimentally manipulated within subjects. Unbeknownst to participants, the illumination of the light bulb was predetermined and irrespective of their behavior. OCD patients exhibited lower estimates of control compared with healthy comparison subjects. There were no interactions between group and outcome density or group and valence. We found that OCD patients endorse lower estimates of control than comparison subjects. This finding highlights a potential role for contingency learning in the disorder.

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