Increased fronto-striatal reward prediction errors moderate decision making in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) has been linked to functional abnormalities in fronto-striatal networks as well as impairments in decision making and learning. Little is known about the neurocognitive mechanisms causing these decision-making and learning deficits in OCD, and how they relate to dysfunction in fronto-striatal networks. METHOD: We investigated neural mechanisms of decision making in OCD patients, including early and late onset of disorder, in terms of reward prediction errors (RPEs) using functional magnetic resonance imaging. RPEs index a mismatch between expected and received outcomes, encoded by the dopaminergic system, and are known to drive learning and decision making in humans and animals. We used reinforcement learning models and RPE signals to infer the learning mechanisms and to compare behavioural parameters and neural RPE responses of the OCD patients with those of healthy matched controls. RESULTS: Patients with OCD showed significantly increased RPE responses in the anterior cingulate cortex (ACC) and the putamen compared with controls. OCD patients also had a significantly lower perseveration parameter than controls. CONCLUSIONS: Enhanced RPE signals in the ACC and putamen extend previous findings of fronto-striatal deficits in OCD. These abnormally strong RPEs suggest a hyper-responsive learning network in patients with OCD, which might explain their indecisiveness and intolerance of uncertainty.

Familiality of neural preparation and response control in childhood attention deficit-hyperactivity disorder.

BACKGROUND: Patients with attention deficit-hyperactivity disorder (ADHD) exhibit difficulties in multiple attentional functions. Although high heritability rates suggest a strong genetic impact, aetiological pathways from genes and environmental factors to the ADHD phenotype are not well understood. Tracking the time course of deviant task processing using event-related electrophysiological brain activity should characterize the impact of familiality on the sequence of cognitive functions from preparation to response control in ADHD. Method Preparation and response control were assessed using behavioural and electrophysiological parameters of two versions of a cued continuous performance test with varying attentional load in boys with ADHD combined type (n = 97), their non-affected siblings (n = 27) and control children without a family history of ADHD (n = 43). RESULTS: Children with ADHD and non-affected siblings showed more variable performance and made more omission errors than controls. The preparatory Cue-P3 and contingent negative variation (CNV) following cues were reduced in both ADHD children and their non-affected siblings compared with controls. The NoGo-P3 was diminished in ADHD compared with controls whilst non-affected siblings were located intermediate but did not differ from both other groups. No clear familiality effects were found for the Go-P3. Better task performance was further associated with higher CNV and P3 amplitudes. CONCLUSIONS: Impairments in performance and electrophysiological parameters reflecting preparatory processes and to some extend also for inhibitory response control, especially under high attentional load, appeared to be familially driven in ADHD and may thus constitute functionally relevant endophenotypes for the disorder.

Differential EMG biofeedback for children with ADHD: a control method for neurofeedback training with a case illustration.

The objective of the present paper was to develop a differential electromyographic biofeedback (EMG-BF) training for children with attention-deficit/hyperactivity disorder (ADHD) matching multiple neurofeedback training protocols in order to serve as a valid control training. This differential EMG-BF training method feeds back activity from arm muscles involved in fine motor skills such as writing and grip force control. Tonic EMG-BF training (activation and deactivation blocks, involving bimanual motor tasks) matches the training of EEG frequency bands, while phasic EMG-BF training (short activation and deactivation trials) was developed as an equivalent to the training of slow cortical potentials. A case description of a child who learned to improve motor regulation in most task conditions and showed a clinically relevant reduction of behavioral ADHD symptoms illustrates the training course and outcome. Differential EMG-BF training is feasible and provides well-matched control conditions for neurofeedback training in ADHD research. Future studies should investigate its value as a specific intervention for children diagnosed with ADHD and comorbid sensorimotor problems.

[The school child with ADHD]. / Das Schulkind mit ADHS.

Attention Deficit/Hyperactivity Disorder (ADHD) is one of the most frequent psychiatric disorders at school age. The core symptoms of hyperactivity, impulsivity and inattention emerge before the age of seven and are associated with severe impairment of the child's everyday functioning (family, school, leisure time). Seventy percent of the affected children show at least one comorbid psychiatric condition or learning disorder/academic impairment. ADHD is one of the most widely investigated disorders in child and adolescent psychiatry. A multitude of imaging (fMRI) and genetic studies comparing children with ADHD and typically developing children have provided clear evidence for the neurobiological foundation of ADHD. Nevertheless, environmental, familial and academic factors play an important role with regard to the persistence and severity of the disorder. Treatment should be preferentially multimodal, with interventions targeting the child, the parents, and, if possible, the teacher. Society with its specific requirements and constraints, and also school, are not well adjusted for children that are different, hyperactive and easily distracted. However, many of these children also have resources. When fascinated by a task, they may show persistence and commitment.

Decision-making on an explicit risk-taking task in preadolescents with attention-deficit/hyperactivity disorder.

Inappropriate risk-taking and disadvantageous decision-making have been described as major behavioural characteristics of patients with attention-deficit/hyperactivity disorder (ADHD). However these behaviours are difficult to measure in laboratory contexts and recent studies have yielded inconsistent results which might be related to task characteristics. The present study adopted the Game of Dice Task, a test procedure in which risks are made explicit and the load on working memory is minimal. As a result, preadolescents with ADHD (N = 23) made significantly more risky choices and suffered major losses of money compared to normal controls (N = 24) but only when they played the game a second time. Differences in risk-taking correlated significantly with hyperactivity as rated by parents and with inhibitory control, but not with working memory performance. The results are discussed in the context of current theories of ADHD.

[An integrated concept for vocational rehabilitation of brain injured patients--a catamnestic study of occupational outcome 1 to 2 years later]. / Ein integriertes Konzept zur beruflichen Wiedereingliederung von hirnverletzten Patienten--eine Katamnesestudie zum beruflichen Outcome 1 bis 2 Jahre später.

Presented is a vocational reintegration concept for clients following craniocerebral trauma and other acquired brain damage. Close dovetailing of vocational and therapeutic measures is advocated, as it is mostly the neuropsychological disorders or problems in behaviour and emotional experience that stand in the way of returning to work. A work experience and adjustment setting holds particularly great potential for addressing these difficulties in a day-to-day life-related, remedial manner. Another focus is follow-up care of those clients who have returned to competitive employment. These clients are called on regularly at their workplace by programme vocational guidance/vocational assessment staff; necessary adaptations are carried out, difficulties dealt with, and possible solutions sought jointly with the employer. A catamnestic study was undertaken to verify how many of the clients included in the programme had achieved long-term resettlement. It was found that the great majority of those who had returned to their former job, have retained their employment some one to two years later, with most of them working at a lower level than before the event. Clients unable to return to their former employer had mostly been pensioned despite the presence of partial working capacity.

Acute respiratory diseases/influenza sentinel 2000/2001.

A sentinel surveillance system of the public health service for acute respiratory diseases (ARD), especially influenza, has been realized in the Free State of Saxony of Germany for 25 years. The epidemiological sentinel is based on weekly registration of morbidity and mathematical-statistical calculations. For a microbiological sentinel, a fast diagnosis by nucleic acid amplification techniques and improvements of sample management in connection with the rapid transmission of results have been introduced. In the present report, the ARD/influenza sentinel is demonstrated for the season 2000/2001. The sentinel system provides scientific and practical information for a prophylactic and therapeutic control program. Economic significance has been proved by verifiable numerical data derived from several epidemiological and microbiological investigations. The realized system has been considered superior to the influenza surveillance scheme of the Arbeitsgemeinschaft Influenza (AGI, Marburg, Germany) for all Germany and another system of a pharmaceutical company which is under construction.