Ereignis-korrelierte lokale feldpotenziale und wavelet-frequenzspektren zur identifizierung von handlungskontrollprozessen im nucleus accumbens

The use of intracranial recordings during the implantation of electrodes for deep brain stimulation offers the opportunity to detect the neural basics of the target structures' cognitive functions with a high spatial and temporal resolution. Here we present the local field potentials from inside the nucleus accumbens (NAcc) of a patient suffering from OCD. We used an Eriksen-Flanker paradigm for investigating action monitoring processes related to the NAcc. A main aspect of action monitoring is the detection and correction of errors. By recording from two distinct sites during the surgery, one directly from inside the shell of the NAcc and the other 5 mm above, we were able to show a specific involvement of the NAcc in the processing of action errors. By using correlative procedures we could also show that this error-specific signal occurs first in the NAcc and then at the surface of the skull. This relationship is mainly caused by variations in the θ band. Furthermore, during correct responses increases in the power of the β band occurred. These findings will be interpreted in terms of the reinforcement learning theory of action monitoring by Holroyd and Coles (2002).