Neurofeedback for alcohol addiction: Changes in resting state network activity✰.

Alcohol dependence continues to be a major global burden despite significant research progress and treatment development. The aim of this study was to investigate whether neurofeedback training can alter resting state fMRI activity in brain regions that play a crucial role in addiction disorders in patients with alcohol dependence. For this purpose, a total of 52 patients were recruited for the present study, randomized, and divided into an active and a sham group. Patients in the active group received three sessions of neurofeedback training. We compared the resting state data in the active group as part of the NF training on six measurement days. When comparing the results of the active group from neurofeedback day 3 with baseline 1, a significant reduction in activated voxels in the ventral attention network area was seen. This suggests that reduced activity over the course of therapy in subjects may lead to greater independence from external stimuli. Overall, a global decrease in activated voxels within all three analysed networks compared to baseline was observed in the study. The use of resting-state data as potential biomarkers, as activity changes within these networks, may be to help restore cognitive processes and alcohol abuse-related craving and emotions.

EEG-neurofeedback training and quality of life of institutionalized elderly women (a pilot study).

This pilot study attempted to study the applicability of neurofeedback for elderly persons living in nursing homes. We hypothesized an improve of cognitive functioning and the independence in daily life (IDL) of elderly people by using low beta (12-15HZ) EEG neurofeedback training (E-NFT). The participants (active E-NFT group, n=10; control group, n=6) were community living elderly women without dementia. Neurofeedback training was adjusted ten times within 9 weeks, with a training duration of 21 minutes by use of a single electrode, which was centrally placed on the skull surface. Executive functioning (measured with the Rey and fluency tasks), memory capacity (measured with the 15 words test), and IDL (measured with the Groningen Activity Restriction Scale) were measured before and after ten E-NFT sessions in nine weeks. No effects were found for IDL nor executive functioning. Interestingly, performance on the memory test improved in the experimental group, indicating a possible positive effect of E-NFT on memory in elderly women. This study demonstrates that E-NFT is applicable to older institutionalized women. The outcome of this pilot-study justifies the investigation of possible memory effects in future studies.

Short and long-term effects of sham-controlled prefrontal EEG-neurofeedback training in healthy subjects.

OBJECTIVE: In this study we evaluated long-term effects of frontal beta EEG-neurofeedback training (E-NFT) on healthy subjects. We hypothesized that E-NFT can change frontal beta activity in the long-term and that changes in frontal beta EEG activity are accompanied by altered cognitive performance. METHODS: 25 healthy subjects were included and randomly assigned to active or sham E-NFT. On average the subjects underwent 15 E-NFT training sessions with a training duration of 45 min. Resting-state EEG was recorded prior to E-NFT training (t1) and in a 3-year follow-up (t3). RESULTS: Compared to sham E-NFT, which was used for the control group, real E-NFT increased beta activity in a predictable way. This increase was maintained over a period of three years post training. However, E-NFT did not result in significantly improved cognitive performance. CONCLUSION: Based on our results, we conclude that EEG-NFT can selectively modify EEG beta activity both in short and long-term. SIGNIFICANCE: This is a sham controlled EEG neurofeedback study demonstrating long-term effects in resting state EEG.

[Neurobiology of obsessive-compulsive disorder]. / Neurobiologie der Zwangsstörung.

In the last few decades, neurobiological research has considerably improved the understanding of the pathophysiological basis of obsessive-compulsive disorder (OCD), indirectly contributing to the improvement of diverse therapy strategies. A number of functional imaging studies have indicated functional deficits in frontostriatal networks, which can be subsumed in an orbitofrontal model of obsessive-compulsive disorder. A dysfunction is postulated in parallel frontostriatal circuits, leading to an imbalance in direct and indirect feedback loops and a disinhibition of thalamocortical activity. Neurochemical studies have shown that OCD is linked to changes of the central modulatory transmitter system, especially, the serotonin and dopamine system, which probably contribute to a direct and indirect dysregulation in various neural networks. Pharmacologically, the elucidation of these serotonergic and dopaminergic alterations and their interactions are of special interest.

Single-trial coupling of the gamma-band response and the corresponding BOLD signal.

Oscillations in the gamma-band frequency range have been described to be more closely connected to hemodynamic changes as assessed with functional magnetic resonance imaging (fMRI) than other aspects of neuronal activity. In addition, gamma-band oscillations have attracted much interest during the last few years since they are thought to play a crucial role in many aspects of brain function related to perception and cognition. It was the aim of the present simultaneous EEG-fMRI study to identify brain regions specifically involved in the generation of the auditory gamma-band response (GBR) using single-trial coupling of EEG and fMRI. Ten healthy subjects participated in this study. Three different runs of an auditory choice reaction task with increasing difficulty were performed. Brain activity was recorded simultaneously with high density EEG (61 channels) and fMRI (1.5 T). BOLD correlates of the GBR have been predicted using the single-trial amplitude of the GBR. Reaction times (p<0.001), error rates (p<0.05) and self-ratings of task difficulty and effort demands (p<0.001) were related to the level of difficulty in the task. In addition, we found a significant influence of task difficulty on the amplitude of the GBR at Cz (p<0.05). Using single-trial coupling of EEG and fMRI GBR-specific activations were found only in the auditory cortex, the thalamus and the anterior cingulate cortex (ACC) in the most difficult run. Single-trial coupling might be a useful method in order to increase our knowledge about the functional neuroanatomy of "neural ensembles" coupled by 40 Hz oscillations.

The neural basis of the P300 potential. Focus on the time-course of the underlying cortical generators.

The locations and time-courses of the neural generators of the event-related P300 potential have been well described using intracranial recordings. However, this invasive method is not adequate for usage in healthy volunteers or psychiatric patients and not all brain regions can be covered well with this approach. With functional MRI, a non-invasive method with high spatial resolution, most of these locations could be found again. However, the time-course of these activations can only be roughly determined with this method, even if an event-related fMRI design has been chosen. Therefore, we have now tried to analyse the time-course of the activations using EEG data providing a better time resolution. We have used Low Resolution Electromagnetic Tomography (LORETA) in the analysis of P300 data (27 electrodes) of healthy volunteers (n = 50) in the time frame 230-480 ms and found mainly the same activations that have been described using intracranial recordings or fMRI, i. e. the inferior parietal lobe/temporo-parietal junction (TPJ), the supplementary motor cortex (SMA) and the anterior cingulate cortex (ACC), the superior temporal gyrus (STG), the insula and the dorsolateral prefrontal cortex. In these selected regions, an analysis of the activation time-courses has been performed.

Simultaneous ERP and event-related fMRI: focus on the time course of brain activity in target detection.

The event-related P300 potential has been widely used in neurophysiological research. It is usually evoked with an oddball paradigm. One main reason for its broad application in neurophysiological research is the fact that in several brain/mental diseases, such as Alzheimer's disease or schizophrenia, attenuations of the P300 amplitude and latency have been described. However, a precise correlation of the scalp data to the underlying brain regions was not possible, as the correct localization of the generators of scalp-measured electroencephalogram (EEG) data was limited, due to the low spatial resolution of EEG-data. With the availability of modern imaging technologies, functional Magnetic Resonance Imaging (fMRI) in particular, the underlying brain activations could be detected using an oddball task. Although the spatial resolution of fMRI is excellent, the time resolution is restricted. For a comprehensive understanding of the brain activity underlying the P300 paradigm, we have used a combination of EEG and fMRI to get a precise localization and a high-time resolution of the underlying brain activity.

Epidemiological, genetic, pharmacological, kinesiological, nuclear medical (IBZM-SPECT), standard and functional MRI studies on Parkinson's disease and related disorders and economic evaluation of Parkinson's disease therapy--clinical projects in the BMFT-research program Munich: "Parkinson's disease and other basal ganglia disorders".

The results of selected clinical research projects related to epidemiological, genetic, pharmacological, kinesiological, and neuroimaging aspects (SPECT, PET, MRI, functional MRI) of basal ganglia disorders such as Parkinson's disease, Progressive Supranuclear Palsy, Multiple System Atrophy and Wilson's disease are summarized. A retrospective pharmacoeconomic analysis of Parkinson's disease is presented. These studies are part of a nationwide research program of the German ministry of research and technology (BMFT) entitled "Parkinson's disease and other basal ganglia disorders" and were carried out at the Department of Neurology, LMU München.