Nathan Crone | PubMed Health

PubMed2005

Analysis of multichannel biomedical data.

Nowadays, there is a common practice in biomedical research to perform multiple time series recordings. In the first part of this paper, basic information about analysis of such multichannel biomedical data is given. A short overview of important differences between single-channel, two-channel and multichannel data sets is presented and various coherence functions are reported. Causal relations between channels are investigated by means of the Directed Transfer Function (DTF) and its dynamic version, the Short-Time Directed Transfer Function (SDTF). The introduced formalism was used to analyze 12-channel human electrocorticogram (ECoG) records. Preliminary results of a study of causal dependence in beta and gamma frequency bands in two patients performing a motor task are reported. Specific characteristics in activity propagation consistent for both subjects for different rhythms were found.

Algorithms↗

PubMed2000

Right Hemisphere Language Dominance in a Right-Handed Patient with Late-Onset Seizures.

Right hemisphere language dominance is rare in right-handed individuals and usually the result of language transfer associated with early left hemisphere pathology. We studied a 33-year-old right-handed man, with a normal MRI scan, who developed left frontal lobe seizures at age 15 years. Language lateralization testing by intracarotid amobarbital injection and dichotic listening showed the patient to be strongly right hemisphere language dominant. The clinical features of this patient do not fit the profile of pathology-induced language transfer, but instead suggest that he was right hemisphere language dominant before developing seizures. This case underscores the importance of language lateralization testing in patients who are candidates for seizure surgery, even if they are strongly right-handed and have late-onset seizures, features usually associated with left hemisphere language dominance. One implication is that the incidence of right hemisphere language dominance in the right-handed population may be underestimated.

Journal Article↗