Quantification of cognitive-induced brain activity: an efficient method for online applications.

Electrical brain responses during performance of cognitive tasks contain not only evoked, but also induced activity reflecting different processes. These activities are often partially overlapped in time and frequency, so that they are even more difficult to be separated in single-trial. Therefore, online applications based on induced brain activity require specific online processing methods to separate both activities efficiently. Here we propose a module-based methodology for the online extraction and quantification of induced brain activity during cognitive-related tasks. Further, the role of electrode montages and the minimization of the evoked activity are examined in both simulated and real data as part of the optimization process.

Neurobrucellosis with thalamic infarction: a case report.

Brucellosis is prevalent in North and East Africa, the Middle East, South and Central Asia, South and Central America and the Mediterranean countries of Europe. In 5% of cases it may lead to central nervous system manifestation presenting most often as a meningitis or meningoencephalitis. Here we report and discuss a case of neurobrucellosis with meningitis with cranial nerves neuritis. A 56-year-old German male was admitted with bilateral abducens nerve palsy, amblyacousia and intractable headaches. An enzyme-linked immunosorbent assay (ELISA) revealed antibodies against Brucella in serum and cerebrospinal fluid (CSF). Additionally, our patient suffered from an infarction of the left thalamus. In conclusion, in cases of unresponsive meningitis or meningoencephalitis and history of travel in endemic regions, neurobrucellosis should be considered. If initial microbiological tests fail, complementary investigations such as ELISA are indicated to detect Brucella species in serum and/or CSF.

Threshold adaptation for mean value based operant conditioning.

Biofeedback and a variety of brain-computer-interface methods imply as very first stages the obtainment of control of selected signals e.g. the related generating psycho-physiological processes. The basic mechanism in the learning phase is the operant conditioning, which represent a complex behavioral method consisting of several components. One of the most important components is the setting and adjustment of thresholds for the triggering of corresponding rewarding options. An adaptive threshold optimization method, for the training based on average values is presented. The procedure is derivated from the sequential test from Wald. The application of the sequential tests in the learning/training process allows a threshold adaptation corresponding to the abilities of the particular person and to the learning success.