Intentional Control of Cortical Areas (ICCA)

It has been known since the 70ies that humans are able to use real-time information to alter brain function. Since recently, it is even possible to regulate cortical activation in specific brain areas using real-time fMRI. However, fMRI-neurofeedback suffers from some limitations, the high costs being only one of them. In addition, inherent delays of the BOLD hemodynamic response lead to delayed feedback, which could, in turn, protract the learning process. To provide an alternative method without these limitations, the proposed project aims to develop an EEG-based neurofeedback procedure that enables the intentional control of localised cortical activity. Healthy subjects will be trained to produce increased or decreased current density in the dorsolateral prefrontal cortex (DLPFC) as an exemplary region. To provide a reasonable spatial resolution, a real-time version of low-resolution electromagnetic tomography (LORETA) will be developed. After the development and implementation of the ICCA procedure in phase 1, phase 2 is devoted to training and evaluation by simultaneous recording of EEG and fMRI. This allows verifying that the activity changes which are voluntarily produced by the subjects indeed occur in the intended region, the DLPFC. Phase 3 serves to test the effect of training on cognitive performance in a reasoning task that is mediated by the DLPFC. Since ICCA allows investigating the effects of systematically enhanced or reduced activity in circumscribed neocortical brain areas, it has the potential to become a valuable tool for neuro-scientific research. Moreover, potential applications may extend to the facilitation of attention and working memory and to clinical therapy.

Neurofeedback is a well established measure in Psychotherapy and in Clinical- and Health-Psychology. However, its efficacy is established just empirically and not by specific models of action. It is established that most people achieve control on brain measures, e.g. a- power or a/ß-ratio, but how that comes about and where in the brain the essential process takes place and if that is equal/similar in different brains is completely unclear. It induced therefore particular interest when Ch. deCharms launched his report on neurofeedback of local brain activity using real time functional magnetic resonance imaging (rtfMRI). With this method it is at least assured that a particular preselected region is involved. Meanwhile about 15 reports on rtfMRI feedback have been published but barely such on practical applications. Since MRI is expensive and not widely accessible and scanners do not offer an attractive therapeutic setting this project aimed to develop and test a comparable EEG-based procedure. To achieve this goal a mathematical procedure (BEM-based SMS- LORETA; [http://arxiv.org/abs/1106.2679] 2011, [http://arxiv.org/pdf/0806.4845] 2008) has been developed that enables localizing all generators within the cerebral cortex for a given scalp potential distribution fast and automatically. Additionally a training-setting has been created where trainees are asked to work on cognitive or motor task and in parallel specific brain signals can be extracted. With Broca aphasia following stroke, for example, the left hemisphere language areas will be in the focus. During the training a series of action naming tasks will be presented where trainees have to find the adequate verb and speak it internally (covered action naming). Whenever during task execution a generator can be identified within the left hemisphere language areas based on the ongoing potential distribution visual feedback via computer monitor will be given according to the generator`s strength. Trainees are instructed to make this more frequently and stronger with ongoing training. The results of an experiment consisting of 13 training runs and 1 `transfer` run, containing 120 tasks each, clearly demonstrated that volunteers are able to accomplish that (Bauer, Pllana & Sailer, 2011). We call this procedure `Local Brain Activity (LBA-) Feedback` - which is the only one of its kind in the world right now that works on EEG-basis. The developed computer program has a graphic user interface and is flexible in a way that applications in various fields are possible from neuro-rehabilitation via psychotherapy and training of cognitive abilities.