Spindles in Sleep and Awake State

The project searches for a better insight into the relationship of spindles and spindle-like activity in sleep and in awake state. In sleep, spindles are predominantly seen in stage 2 having a frequency of 12-14Hz. In awake state, synchronization patterns with a frequency of 10-14Hz can be observed. Interactions in specific (relay cells) and reticular neurons of the Thalamus are supposed to play a role in the generation of both patterns. Both induced phenomena, spindles and spindle-like activity, might share the same functional role, namely the blocking of thalamocortical information transfer. Since the frequency range overlaps, it is of interest to study both phenomena with special emphasis on common features. Basic parameters (frequency, duration,...) of automatically detected sleep spindles out of whole-night polysomnograms are measured with time-frequency analysis methods. These data are used to generate a spindle prototype. To clarify the relationship of spindles and spindle-like activity, EEG data will be recorded from 15 healthy subjects in two experiments involving awake and sleeping states. In these experiments periodic visual or tactile stimulation will be applied for some hours to induce a state of drowsiness and light sleep. The recorded spindling patterns will be compared to the sleep spindle prototype with respect to their features. In two further experiments motor and verbal tasks known to produce synchronization pattern...(this text has been cut automatically)