The long-term vision
The envisioned long-term goal is to provide neuro-scientific knowledge, methods and technologies which allow wireless acquisition and interpretation of neuronal activity patterns related to specific cognitive states in real time. Furthermore, effective and detailed feeding of information into ongoing neuronal processing should be possible. The combination of “reading” and “writing” allows a highly differentiated interaction with the brain and will be used for the construction of cerebral visual and other sensory prostheses providing the user with a high quality of perception. The device should be medically safe with a life-time of several decades. The complete system includes hardware and software as well as neuro-scientific methods and basic knowledge of the interactions with the brain.
The knowledge and technologies which will emerge from our scientific goal will open up other research areas and applications like:
* Neuronal mechanisms of complex cognitive processes which are based on the interaction of multiple sub-systems of the brain.
* Pathophysiology of complex neurological and psychiatric disorders.
* Substantially improved control of neuronal prostheses which provide the user with a sensory feed-back ("sensing prosthetic hand")
* Fast and efficient communication with locked-in patients (stroke, ALS, etc.) through highly differentiated acquisition and interpretation of non-motor cognitive states such as selective attention
* Control of different types of auxiliary devices by severely disabled patients to recover personal autonomy
* Automatic detection of pathological brain states and intervention by dynamically adapted electrical stimulation (e.g. disrupting seizure activity)
* Closed-loop-systems for influencing pathological psychiatric states (e.g. anxiety disorders) or neurological states (e.g. Parkinson's disease).
* Automatic, on-demand local transfusion of neuro-pharmaceutical drugs depending on local brain states, for minimizing the volume of these substance and thus their side effects.
* Telemedical detection of acute medical hazards, like uprising seizure activity and other pathological conditions.
A hallmark of the technologies and methods, which will be developed in the course of our key objective, is their flexible adaptability to brain structure, recording task and stimulation requirement. Highly differentiated acquisition of neuronal activity in distributed processing networks will be achieved by weakly invasive electrode arrays which follow the curvature of the brain and therefore allow simultaneous, spatially specific recording from thousands of electrodes. Moreover, feeding-in of information with electrical or optogenetic methods will be possible. The carrier substrate of the electrode array will dissolve after implantation, leaving a bio-compatible mesh of electrodes. The electronics for signal acquisition, stimulation and wireless transmission of data and energy will be flat, error tolerant and low in component number; it will be integrated in the flip-side of the array.
In a complimentary approach, arrays of multi-contact needles will allow recording of action potentials and local field potentials in all layers of the cortical column as well as in brain areas which are not accessible with surface electrodes. At the same time, complex electrical and/or opto-genetical stimulation patterns can be applied with high spatio-temporal resolution. The needles are equipped with electronics; they almost completely submerge in the tissue, are atraumatic and do not trigger immune reactions.
Surface and needle arrays can be used in combination. They allow closed-loop applications, where recorded signals are used to generate stimulation patterns. Furthermore, the recorded data allow conclusions about dynamics and function of brain areas and processing pathways, thereby providing parameter constraints for biologically plausible neuronal models. These models will enable identification and quantification of (possibly pathological) neuronal activation patterns and current information processing. Moreover, the models are crucial for developing stimulation patterns which evoke quasi-natural activity patterns suitable for feeding in sensory information or generating specific network states.