The Reticular Activating System

The reticular activating system (RAS) is a network of neurons located in the brain stem that project anteriorly to the hypothalamus to mediate behavior, as well as both posteriorly to the thalamus and directly to the cortex for activation of awake, desynchronized cortical EEG patterns.  From: Textbook of Clinical Neurology (Third Edition), 2007

The reticular activating system spans an extensive portion of the brainstem. Most of the neurons comprising the midbrain reticular formation lie dorsal and lateral to the red nuclei. Complex interactions between multiple neurotransmitters modulate the action of the reticular activating system with both cholinergic and adrenergic neurotransmission having key roles. The reticular activating system's fundamental role is regulating arousal and sleep−wake transitions. The ascending reticular activating system projects to the intralaminar nuclei of the thalami, which projects diffusely to the cerebral cortex. The ascending projections of the reticular activating system enhance the attentive state of the cortex and facilitate conscious perception of sensory stimuli. Additionally, the collective role of the brainstem reticular formation is to regulate autonomic function, muscle reflexes, and tone. From:  Encyclopedia of the Neurological Sciences (second edition)

According to The Pacific Institute, the reticular activating system regulates mental motivation and the subconscious movement towards a goal or a destination through not just positive affirmation but actually believing that you deserve the goal...  I know this for a fact because I was sent to a 3 day class by my employer that was being taught by employees of The Pacific Institute.