The results confirm that the subjective reality areas of both subjects with their varied worlds of experience also produce different neuronal events in the cortex under the objective conditions of the experimental design. The information content of the signal from the outside, as well as the inside world, is determined by prior subjective knowledge. The data clearly demonstrated that subjects were able to concentrate on the known technical elements of the dance and were able to reproduce the complete dance in their imagination with the sequences intact in movement order and timing. Second, mental fatigue occurring after a series of eight mental rehearsals of a choreographed dance is clearly documented by both EEG and EMG results. The mental representation of motor activity affects all cortical areas, although the executor portion of the motor control loop is not activated. Increased concentration on the mental rehearsal resulted in increased ß- frequency activity and neural activation, leading to changes in the corresponding physiological changes in the cardiorespiratory and EMG responses. Increasing mental load results in increased fatigue and inability to maintain high levels of concentration while the cardiorespiratory responses decrease. The current series of investigations confirm that the demands placed on mental activity do not occur in isolation but are multifaceted and very complex. Cognitive loading provides the opportunity to study these demands which are affected by a combination of factors, including fatigue, prior experience, motor patterns, social context, and emotional state.

Department of Sport Science Otto von Guericke Univerity Magdeburg

Brno, 8.-9. listopadu 2007