Selye situated his work primarily within studies of traumatic shock and toxicology , although his research took place within a wide contemporary interest in adaptation in general . Concerns about the impact of social and technological change on human health and on the limits of adaptability were clearly shaped not only by increased knowledge of physiology but also by fears about increasing levels of mental stress , fatigue , and traumatic neurosis among industrial workers and returning soldiers .( 9 ) Notable among these who studied these psychosocial developments was Francis Crookshank ( 1873-1939 ) who observed in 1923 that :
“ The fact is that , at the present time , social change — industrial , economic , and the like — is everywhere modifying the conditions of life more rapidly than we care to admit ; — far more rapidly for the exercise of the natural powers of adaptation of the human race .” ( 10 , p . 248 )
Some authors say that it was Walter Cannon ’ s description of what he termed ' social homeostasis ' that actually provided the blueprint for Selye ’ s subsequent construction of a ' natural philosophy of life ', which was put forward to aid people in maintaining or restoring individual happiness and social stability . Cannon also coined the term ' fight or flight ' and , as an interesting side bar , discovered , along with other notable researchers of the time , that saline infusions could be used to treat shock .( 11 )
In the modern age , the importance of the autonomic nervous system is viewed not only in terms of the physical health of heart , vasculature , digestion etc . but also as a significant determinant of our personal subjectivities – our sense of who we are , how we feel and how we behave . Giving attention to these subjectivities – our sense of self - is a relatively new phenomenon in the global West . By way of contrast , in the global East explorations of the inner landscape of mind and body via meditation and yogic practices have been a central part of Hinduism and Buddhism for at least four thousand years . Borrowing a term from the renowned Harvard psychologist , William James , – who , incidentally , praised the ability of yoga to stabilise the nervous system and restore or unleash ' unused reservoirs of power ' in a presidential address to the American Philosophical Society in 1906 ( 12 ) – Alan Wallace calls this method of enquiry into personal experience ' radical empiricism '. Stillness in the mind and body can lead to higher knowledge ( insight ) as well as heightened states of consciousness that transcend the ' noise ' of everyday states of mind , or discursiveness .( 13 )
In the 1960s research into the ANS by Gellhorn led him to propose a neurophysiological explanation for these states of calmness and insight as being associated with a concordant increase in the activity of the parasympathetic branch of the ANS .( 14 ) Like Langley , he observed that the sympathetic nervous system ( SNS ) and parasympathetic nervous system ( PNS ) operated in a process of reciprocal inhibition whereby an increase in the activity in one branch would lead to a suppression of the other . Gellhorn observed that the ANS could become ' tuned ' in one direction or another and , rather than exhibit a sinusoidal wave of SNS and PNS activity throughout the day , the ANS would get stuck , usually in SNS arousal , and develop a new baseline there . Access to feelings of calmness and high levels of reflective thought is lost when the ANS is tuned in this way . Self-regulation and emotional well-being become increasingly difficult as the fight or flight processes associated with the SNS are in a constant state of ' on '.
The capacity of certain kinds of manual therapy to ' unstick ' this static condition was well illustrated in Cottingham ’ s study into the effects of the Rolfing method of myofascial treatment and structural alignment .( 15 ) His research made use of a Vagal Tone Monitor ( VTM ), used before , during and after Rolf style myofascial release . The VTM monitors fluctuations in the Respiratory Sinus Arrhythmia ( RSA ) to determine the outflow of the vagus nerve . The initial study demonstrated a reflexive spike in PNS activity during a procedure and a follow up study showed that the baseline of PNS activity could be shifted as a result of a series of ten Rolf-style myofascial release ( MFR ) soft-tissue treatments . Forty years on , this dynamic of tuning , and the associated loss of what Cottingham termed ' autonomic flexibility ', is now being taken up in the context of heart rate variability and its relationship to health , fitness and rehabilitation ( 15 ) ( see Figure 1 ).
Figure 1 . Changes In heart rate associated with breathing ( 15 )
Another important contribution from Gellhorn is his research that shows muscle tone and hypothalamic and emotional excitability are positively correlated . What does this mean in practical terms ? Basically , it shows that willed changes in muscle tone may be used to control emotions , although at the conclusion of the same article he acknowledged that this is difficult to achieve in situations that are arousing negative , or in other ways uncomfortable , states .( 16 )
Gellhorn ’ s research also looked at the ANS in terms of its integrations , or lack thereof , with the somatic systems . Ergotropic ( SNS ) and Trophotropic ( PNS ) tuning were investigated at the level of the cerebral cortex , along with the effects they had on hypothalamic temperature .( 14 ) His work was seminal and created a framework for the complex re-appreciation of the ANS that is at the heart of Polyvagal Theory .
20 | vol29 | no1 | JATMS