"Neural efficiency" of athletes' brain for upright standing: a high-resolution EEG study.

"Neural efficiency" hypothesis posits that neural activity is reduced in experts. Here we tested the hypothesis that compared with non-athletes, elite athletes are characterized by a reduction of cortical activation during an engaging upright standing. EEG (56 channels; Be-plus Eb-Neuro and stabilogram (RGM) data were simultaneously recorded in 10 elite karate, 10 elite fencing athletes, and 12 non-athletes during a simple bipodalic (standard Romberg) and a more engaging monopodalic upright standing. Balance was indexed by body "sway area". The EEG data were spatially enhanced by surface Laplacian estimation. Cortical activity was indexed by task-related power decrease (TRPD) of EEG alpha power (8-12Hz) during monopodalic referenced to bipodalic condition. The body "sway area" was larger during the monopodalic than bipodalic upright standing in all groups. Low-frequency alpha TRPD (about 8-10Hz) was lower in amplitude in the karate and fencing athletes than in the non-athletes at left central, right central, middle parietal, and right parietal areas (p<0.01). Similarly, the amplitude of high-frequency alpha TRPD (10-12Hz) was lower in the karate and fencing athletes than in the non-athletes at right frontal, left central, right central, and middle parietal areas (p<0.03). These results suggest that during monopodalic referenced to less engaging bipodalic condition, the power decrease (i.e. the desynchronization) of cortical activity at alpha rhythms is largely reduced in elite athletes than in non-athletes, in line with the "neural efficiency" hypothesis. The present study extends our understanding of the physiological mechanisms at the basis of the "neural efficiency" for engaging upright standing in elite athletes.

Auditory evoked potential abnormalities in cluster headache.

Mid-latency and long-latency auditory evoked responses were investigated in 27 patients with cluster headache who had a mean age of 38.7+/-9.7 years and who were free of pain at the time of testing. Twenty-five age-matched healthy persons served as controls. Latencies and amplitudes of corresponding responses (N100, P200, and P300) were measured. The parameters were calculated at Pz for the P300 and Cz electrodes for the N100 and P200. Multiple analysis of variance revealed a significant overall effect of group (P=0.011). P200 amplitude was significantly smaller in cluster headache patients (P=0.0002). No differences were found for N100 or P300. These data suggest a hitherto unrecognized defect in the information processing pathways, in the early attentive phase represented by the P200 component.