EEG record of brain activity and wave patterns from a sleeping boy.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/75041855@N00">Jemaleddin Cole</a> from Glen Burnie, USA
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jemaleddin/137252626/">EEG with sleeping boy</a>