Vagus somatosensory evoked potentials are delayed in Alzheimer's disease, but not in major depression.

In Alzheimer's disease (AD), the degeneration of brainstem nuclei is different from major depression (MD). Thus, vagus somatosensory evoked potentials (VSEP) proposed for the functional assessment of brainstem nuclei should show prolonged latencies in AD but not in MD. In 55 AD patients, 57 MD patients and two age-matched control groups evoked potentials were recorded upon stimulation of the auricular branch of the vagus nerve.

Dopamine transporter (DAT1) and dopamine receptor D4 (DRD4) genotypes differentially impact on electrophysiological correlates of error processing.

Recent studies as well as theoretical models of error processing assign fundamental importance to the brain's dopaminergic system. Research about how the electrophysiological correlates of error processing--the error-related negativity (ERN) and the error positivity (Pe)--are influenced by variations of common dopaminergic genes, however, is still relatively scarce. In the present study, we therefore investigated whether polymorphisms in the DAT1 gene and in the DRD4 gene, respectively, lead to interindividual differences in these error processing correlates.

Electroconvulsive therapy resolves cortical inhibition and manneristic omissions in a chronic catatonic patient.

We investigated a patient with severe catatonic schizophrenia (manneristic catatonia according to Karl Leonhard) treated with electroconvulsive therapy (ECT) after pharmacological approaches did not result in any clinical improvement. Before and after nine ECT sessions a double-pulse transcranial magnetic stimulation (TMS) paradigm was used to measure intracortical inhibition (ICI) which has been shown to be reduced in a significant proportion of patients with schizophrenia. Although the patient showed no remission regarding some psychomotor aspects after ECT, we found an increase in ICI and a remarkable clinical improvement of catatonic omissions which might be due to changes in the GABAergic system.

The effect of ADHD symptoms on performance monitoring in a non-clinical population.

Recent studies suggested deficits in error processing in patients with Attention Deficit Hyperactivity Disorder (ADHD), but some inconsistencies are still present. Using the ADHD screening questionnaire, the Adult ADHD Self-Report Scale, we investigated the association between the amount of inattention and hyperactivity/impulsivity symptoms in a non-clinical population of healthy students (n=56) and the neural correlates of error processing measured with event-related potentials. We found reduced amplitudes of error-positivity (Pe) with increasing symptoms of inattention, but no correlation with error-related negativity.

Neural correlates of performance monitoring in adult patients with attention deficit hyperactivity disorder (ADHD).

Introduction: In this study, the neural correlates of error processing in adult patients with attention deficit hyperactivity disorder (ADHD) are to be investigated for the first time. Recent studies in children with ADHD suggested, with some inconsistencies, deficits in error processing. Based on an analogue study with students, we hypothesized that ADHD patients show reduced amplitudes in the event-related potential (ERP) of the Pe (error positivity) but normal amplitudes of the ERN (error-related negativity) after incorrect responses.