Spectral analysis of electroencephalography changes after choking in judo (juji-jime).

Abstract

The present study was carried out to investigate possible electroencephalographic changes induced by choking in judo (shime-waza) by means of spectral analysis and brain mapping. Power spectral changes in Electroencephalography (EEG) were recorded in six experienced judoka who underwent a choking trial with a "shime-waza choking" technique called juji-jime. A significant increase of global field power in the delta- and theta-range occurred, while physiological alpha-power decreased. These changes in the low-frequency range reached a statistically significant level within a time span up to 20 s after choking, which was performed at an average choking time of 8 s. In no case did choking provoke neuropsychological symptoms. Yet, spectral EEG-analysis revealed subclinical changes of brain function. Choking in judo may induce subclinical electroencephalographic perturbations. The extent and duration can be objectified by means of spectral analysis of EEG data, global field power computation, and brain-mapping representation.