The effect of prediction error on overt attention and learning in humans.

It has been suggested that attention modulates the speed at which cues come to predict contingent outcomes, and that attention changes with the prediction errors generated by cues. Evidence for this interaction in humans is inconsistent, with divergent findings depending on whether attention was measured with eye fixations or learning speed. We included both measures in our experiment.

Hunger and Satiety Peptides: Is There a Pattern to Classify Patients with Prader-Willi Syndrome?

Hyperphagia is one of the main problems of patients with Prader-Willi syndrome (PWS) to cope with everyday life. The underlying mechanisms are not yet well understood. Gut-brain hormones are an interrelated network that may be at least partially involved.

Neural correlates of fear conditioning and fear extinction and its association with cognitive-behavioral therapy outcome in adults with obsessive-compulsive disorder.

Recent neurobiological models of obsessive-compulsive disorder (OCD) have highlighted the potential role of abnormalities in fear learning processes. We compared brain activation -as assessed with whole-brain functional magnetic resonance imaging- during fear conditioning, fear extinction learning, and fear extinction recall in patients with OCD (n = 18) and healthy controls (n = 18). We also investigated whether brain activation during any of these processes was associated with exposure-based cognitive-behavioral therapy (CBT) outcome in patients.

Evidence for two attentional mechanisms during learning.

We sought to provide evidence for a combined effect of two attentional mechanisms during associative learning. Participants' eye movements were recorded as they predicted the outcomes following different pairs of cues. Across the trials of an initial stage, a relevant cue in each pair was consistently followed by one of two outcomes, while an irrelevant cue was equally followed by either of them.

Altered Gesture Imitation and Brain Anatomy in Adult Prader-Willi Syndrome Patients.

Objective: To explore motor praxis in adults with Prader-Willi syndrome (PWS) in comparison with a control group of people with intellectual disability (ID) and to examine the relationship with brain structural measurements.

Method: Thirty adult participants with PWS and 132 with ID of nongenetic etiology (matched by age, sex, and ID level) were assessed using a comprehensive evaluation of the praxis function, which included pantomime of tool use, imitation of meaningful and meaningless gestures, motor sequencing, and constructional praxis.

Results: Results support specific praxis difficulties in PWS, with worse performance in the imitation of motor actions and better performance in constructional praxis than ID peers.

A rise in prediction error increases attention to irrelevant cues.

We investigated whether a sudden rise in prediction error widens an individual's focus of attention by increasing ocular fixations on cues that otherwise tend to be ignored. To this end, we used a discrimination learning task including cues that were either relevant or irrelevant for predicting the outcomes. Half of participants experienced contingency reversal once they had learned to predict the outcomes (reversal group, n = 30).

Compulsions in Prader-Willi syndrome: occurrence and severity as a function of genetic subtype.

Introduction: Compulsions are among the most typical behaviors in Prader-Willi syndrome (PWS). The most frequent causes of PWS are deletion of the genes located in the segment 15q11-q13 of the paternal allele and maternal uniparental disomy of cromosome 15. The aim of the present work was to study compulsive behavior in a sample of adults with PWS and analyze potential differences as a function of the genetic cause/subtype.

High Incidence of Copy Number Variants in Adults with Intellectual Disability and Co-morbid Psychiatric Disorders.

A genetic analysis of unexplained mild-moderate intellectual disability and co-morbid psychiatric or behavioural disorders is not systematically conducted in adults. A cohort of 100 adult patients affected by both phenotypes were analysed in order to identify the presence of copy number variants (CNVs) responsible for their condition identifying a yield of 12.8% of pathogenic CNVs (19% when including clinically recognizable microdeletion syndromes).

Attentional Control and Fear Extinction in Subclinical Fear: An Exploratory Study.

Attentional control (AC) and fear extinction learning are known to be involved in pathological anxiety. In this study we explored whether individual differences in non-emotional AC were associated with individual differences in the magnitude and gradient of fear extinction (learning and recall). In 50 individuals with fear of spiders, we collected measures of non-emotional AC by means of self-report and by assessing the functioning of the major attention networks (executive control, orienting, and alerting).

Does fear extinction in the laboratory predict outcomes of exposure therapy? A treatment analog study.

Fear extinction models have a key role in our understanding of anxiety disorders and their treatment with exposure therapy. Here, we tested whether individual differences in fear extinction learning and fear extinction recall in the laboratory were associated with the outcomes of an exposure therapy analog (ETA). Fifty adults with fear of spiders participated in a two-day fear-learning paradigm assessing fear extinction learning and fear extinction recall, and then underwent a brief ETA.

Translation and validation of the Spanish version of the Health of the Nation Outcome Scales for People with Learning Disabilities (HoNOS-LD).

Introduction: The Health of the Nation Outcome Scales for People with Learning Disabilities (HoNOS-LD) is a brief instrument that assesses functioning in people with intellectual development disorder and mental health problems/behaviour disorders. The aim of the present study was to examine the evidence on the validity of the scores based on the Spanish version of the HoNOS-LD.

Material And Methods: The study included 111 participants that were assessed by the Spanish version of the HoNOS-LD and other questionnaires that measured different variables related to the scale.

Lack of Postprandial Peak in Brain-Derived Neurotrophic Factor in Adults with Prader-Willi Syndrome.

Context: Prader-Willi syndrome (PWS) is characterized by severe hyperphagia. Brain-derived neurotrophic factor (BDNF) and leptin are reciprocally involved in energy homeostasis.

Objectives: To analyze the role of BDNF and leptin in satiety in genetic subtypes of PWS.

Conditioned Fear Acquisition and Generalization in Generalized Anxiety Disorder.

Abnormal fear conditioning processes (including fear acquisition and conditioned fear-generalization) have been implicated in the pathogenesis of anxiety disorders. Previous research has shown that individuals with panic disorder present enhanced conditioned fear-generalization in comparison to healthy controls. Enhanced conditioned fear-generalization could also characterize generalized anxiety disorder (GAD), but research so far is inconclusive.

Testing the temporal stability of individual differences in the acquisition and generalization of fear.

We studied the temporal stability of individual differences in the acquisition and generalization of fear. Seventy-one participants were tested in two almost identical fear-acquisition and fear-generalization sessions (separated by 8 months). Acquisition and generalization were measured by the fear-potentiated startle, the skin conductance response, and online expectancies of the unconditioned stimulus.

Conditioned Subjective Responses to Socially Relevant Stimuli in Social Anxiety Disorder and Subclinical Social Anxiety.

Unlabelled: Although enhanced fear conditioning has been implicated in the origins of social anxiety disorder (SAD), laboratory evidence in support of this association is limited. Using a paradigm employing socially relevant unconditioned stimuli, we conducted two separate studies to asses fear conditioning in individuals with SAD and non-clinical individuals with high social anxiety (subclinical social anxiety [SSA]). They were compared with age-matched and gender-matched individuals with another anxiety disorder (panic disorder with agoraphobia) and healthy controls (Study 1) and with individuals with low social anxiety (Study 2).

No effect of trait anxiety on differential fear conditioning or fear generalization.

Previous studies have shown that individuals with anxiety disorders exhibit deficits in fear inhibition and excessive generalization of fear, but little data exist on individuals at risk from these disorders. The present study examined the role of trait anxiety in the acquisition and generalization of fear in 126 healthy participants selected on the basis of their trait-anxiety scores. Measures of conditioning included fear-potentiated startle, skin conductance response and online risk ratings for the unconditioned stimulus.

Acquisition and generalization of fear conditioning are not modulated by the BDNF-val66met polymorphism in humans.

Few studies have investigated the role of the BDNF-val66met polymorphism in fear conditioning in humans, and previous results have been inconsistent. In the present study, we examined whether the BDNF-val66met was associated with differences in the acquisition and generalization of fear during a differential conditioning paradigm in a large sample of participants (N = 141). Using three different indexes of fear learning (fear-potentiated startle, skin conductance response, and online risk ratings) no effects of the BDNF-val66met were found either on the acquisition or the generalization of conditioned fear.

Impact when receiving a diagnosis: additive and multiplicative effects between illness severity and perception of control.

Based on Lazarus' transactional model of stress, this study examined how the information provided in a medical diagnosis (the severity of the illness, the effectiveness of the treatment and the self-efficacy to follow this treatment) are combined to generate perception of stress. Twenty-seven scenarios were presented to 152 volunteer students and their level of perceived stress was recorded. Results revealed that the lack of efficacy of the treatment raises the perception of stress proportionally to the different degrees of illness severity, but having a low perceived ability to follow the treatment triggers high levels of stress, particularly when the diagnosis is serious.