Adults and children who have Sensory Processing Disorder (SPD) have been shown to have a depressed Reticular Activating System (RAS) when a Positron Emission Tomography (PET) scan is done (A PET scan is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body).
Consider the functions of a flight deck on an aircraft carrier. Aircraft come and go, receiving direction as to where it is they are going. The types of aircraft that take direction from this important landing strip vary and are vast. If the flight deck gives misdirection, the aircraft is not safe and could be lost in an ocean or disintegrate on contact. Therefore, in order to avoid disintegration, the existence of integration is necessary. Similar to the aircraft carrier, our brain has a place of integration for the information that comes and goes.
The reticular formation is a network of neurons within the brainstem that acts as a place of integration (Sherwood, 1997). Just like the flight deck of an aircraft carrier, the reticular formation has many functions taking place at any given time. When the reticular formation is not functioning properly, input and output is not reaching its proper destination.
This group of neurons, that is the reticular formation, has extensive connections to many different areas of the brain (Siegel, 1979a). They extend from the medulla to the forebrain and are found throughout the brainstem wherever specific neural tracts or nuclei do not exist (Best, n.d.). This network is responsible for receiving and integrating synaptic input (Sherwood, 1997). There are two components of the reticular formation, ascending and descending. The ascending reticular formation is referred to as the reticular activating system (RAS) (McCaffrey, 1998).
While the RAS entertains reference more often, the descending reticular formation also has an important role as it is involved with the spinal cord. Posture, equilibrium and autonomic nervous system activity are all functions in which the descending reticular formation has a role (McCaffrey, 1998). The descending reticular formation also receives information from the hypothalamus and takes part in motor movement (1998, Kalat, 2007 Seigel, 1979b). Coughing, chewing and swallowing are reflexive behaviors in which the descending reticular formation has a part (1998). The reticular formation shows immense activity with specific head and body movements making the vestibular system a powerful sensory system (Seigel, 1979a).
The RAS is foundational in so many functions. In order for the RAS to function properly, it relies upon neurochemicals from the brainstem (Hadley, n.d.). The neurochemicals that the RAS rely on are dopamine, norephrine and serotonin. Dopamine being mostly involved in activation or motoric functions, norephrine being essential for arousal or orienting and perceptual processing and serotonin having a broad tonic and inhibitory purpose (n.d.). The motivational systems, specific focused attention, memory functions, and the affect system all rely heavily on the organization of the RAS (n.d.).
Arousal is a very notable function of the RAS. The RAS works with the chemicals of the brainstem, norephrine, and output to the cerebral cortex creating arousal and attention, stimulating wakefulness (Kalat, 2007, Molavi, 1997). Thus, having a primary affect on sleep and waking cycles. The RAS has been studied in depth as it relates to sleep and more specifically to REM sleep. The intent to isolate the set of neurons responsible for REM sleep was frustrated when the studies showed how interrelated several different systems were in the production of REM sleep (Seigel, 1979b). The studies did show that two of the aspects of REM sleep and other levels of sleep that the reticular formation was involved in were eye movement and motor output (1979b). Motor output being present during the waking cycle and in startle response (1979b).
An infant utilizes the RAS for the most basic survival such as respiration, temperature, sleep and wake cycles (Williams, & Shellenberger, 1996). For learning, a child requires arousal in order to attend, concentrate and complete tasks (1996). A more in depth function is self-regulation, which requires involvement from the brainstem, RAS, formulation, hypothalamus, thalamus, autonomic nervous system, cerebellum, limbic system, cortex and all sensory systems (1996). Self-regulation entails the ability to attain, maintain and change levels of arousal in accordance to the situation (1996).
1) First
a) Automatic functions
i) Temperature
ii) Blood pressure
iii) Respiration
iv) Sleep/wake cycles
v) Ingestion/digestion/elimination
vi) Integrated function of nervous, endocrine and immune systems
b) Muscle/cortical tone
c) State maintenance
d) Monitoring for survival
2) Second
a) Suck/swallow/breathe synchrony
b) Selective attention
c) Visual searching, monitoring and directing
d) Adaptive movement
e) Vocalization in patterns
f) Ability to achieve, maintain and change situation appropriate states
3) Third
a) Intention
b) Sustained attention
c) Working memory
d) Choice of a goal
e) Anticipatory planning
f) Planning
g) Formulation of strategies
h) Execution of strategies
i) Evaluation of strategies
j) Self-monitoring
k) Problem solving
l) Voluntary, goal directed behavior
m) Language for organization
n) Recognition of need for state change/maintenance
o) Organization of spaces, time, tasks, environments (Williams, & Sherberger, 1996)
Turning on the brain is a job for the RAS (ADD/ADHD, n.d.). The ability of an individual's RAS to function properly determines whether they will be impulsive, hyperactive, highly motivated or if they will be able to learn and remember (n.d.). Processing information is not possible without this system and is only possible to the extent in which it is functioning properly or efficiently. A person that has an overactive RAS could be easily startled, hyper vigilant, may need to self stimulate by rocking or touching something, and may talk incessantly (n.d.). An under active RAS leads to difficulty learning, absent-mindedness, lack of self-control and at its extreme, coma (n.d.) found on the other end of the spectrum.
With an awareness of how the RAS functions, it is instrumental in self-improvement. The RAS is preprogrammed for fight or flight instinct and is often responsible for the fear that holds a person back when anticipating a negative outcome (Davies, n.d.). Davies suggests a formula to overcome this fear of anticipated pain when dealing with personal success, "Specific Declarations + Accountability = Elite Performance" (n.d.). Davies recommends a decision about what you want by answering the question "why bother" and then decide what actions you will take to achieve the goal and more specifically what you will do in the next seven days to achieve the goal (n.d.). Then take part in two levels of accountability, check in, preferably with another person and determine if you did what you planned and a painful consequence if you did not follow through (n.d.). The painful consequence stimulates motivation for the desired outcome, putting the RAS to work for your own benefit.
This method can be taken one-step further by putting the goal into writing. When a person takes the time to write a goal down, they are stimulating the RAS and making the written goal a piece of important information that the RAS will pay attention to (Thinkarete.com, n.d.). That goal becomes a focus of the brain and solutions will be more apparent because the person has it readily available, similar to noticing how many vehicles like your own are on the road (n.d.). A vehicle similar to your own is noticeable because you are aware of it, it's a piece of important information.
Dr. Josephine Moore, Ph.D., OTR, has the four A's of the reticular formation: asleep, awake, alert, and attend (Williams, & Shellenberger, 1996). She also points out the RAS as a regulator for cell threshold and a generator of rhythm for the nervous system including circadian rhythm (1996).
The Individualized Sensory Program offered by Vortex Sensory Rehabilitation Center, LLC has obtained a variety of results and improvement of quality of life. For a man with Asperger's, nerves awakened in his skin allowing him to feel himself shave, colors became vivid and distinct, flat affect was lost, humor understood. For an autistic child, giggles and grins appeared where none had been before, touch was bearable making hugs and kisses possible, and anxiety was relieved. A man with a traumatic brain injury regained use of a hand and arm, was able to open both of his eyes, and finally had regulated sleep patterns. A grieving widow was able to process the death of her husband and regain the enjoyment in her life. A victim of a stroke was able to regain the ability to read and comprehend information from her favorite books and regain energy that was lost with the stroke. Common to many people of differing diagnoses was the ability to focus, diminished anxiety and stress levels, comprehension of language and better coping mechanisms.
It is all about the flight deck. When the air control is coordinated, the runway is in good repair, and all of the input and output is integrated properly, the flight deck runs safely and appropriately. If the reticular formation, ascending and descending, integrate appropriately and the input and output takes the most efficient path, overall attention, arousal, motivation, etc. takes place. When the runway is bumpy or the controller is untrained, processing slows and sometimes comes to a complete stop in order to accommodate the inefficiencies. The brain will accommodate in any way it can and sometimes it means the slowing of processing, resulting in difficulty learning and comprehending as well as slowing or hyperactivity in other sensory or nervous systems.