ABSTRACT
The human brain is a remarkable thing. Research has highlighted the central importance to arousal of the reticular activating system (RAS), a cellular circuit, arising in the brainstem and electrochemically increasing cortical activity, and thereby modulating attentional processing. Yerkes and Dodson described an inverted U-shaped function in which low levels of arousal and excessive levels of arousal were associated with reduced attention performance. Children with a diagnosis of attention deficit hyperactivity disorder (ADHD) can have problems in maintaining their attention during school activities. They examined the relative effects of preferred music, disliked music, improvised music entrained to respiration, white noise, and silence on participants' behavioral responses, electroencephalogram (EEG) activity, heart rate variability, and respiration. Future scale clinical trials answers how best to integrate transcranial direct current stimulation (tDCS) with existing therapy and whether persisting effects generalize. Further work is required to develop and evaluate behavioral, biofeedback, pharmaceutical, and possibly non-invasive brain stimulation techniques to enhance alertness.
