Systematic Desensitization – A Brief Synopsis

Abstract:  Systematic desensitization is a form of therapy based on classical and operant conditioning used primarily to help individuals cope with phobias, as well as a number of other problematic behaviors that cause distress to the individuals.  Since a phobia is learned, it is believed that “un-learning,” or counterconditioning, the phobia is possible.  Conditioning was first discovered by Ivan Pavlov in his famous dog salivation experiments.  Pavlov’s ideas were expounded upon by psychologists John Watson, Mary Cover Jones, and Joseph Wolpe years later.  This allowed for the development of the counter-conditioning techniques of systematic desensitization and graduated exposure therapy to alleviate anxiety related to phobias in individuals who had learned to fear certain objects or situations.  Today, these techniques are effective and used in a variety of ways to treat phobias and other behavioral problems.  The conditioning techniques are still being explored and developed by researchers, and it will be interesting to see what future directions will be taken in further development of phobia and behavioral treatment.

                                                                                                                                                                                 

Systematic desensitization is a form of therapy used primarily to help individuals cope with phobias, as well as a number of other problematic behaviors that cause distress to individuals.  Graduated exposure therapy, a form of systematic desensitization (at times used synonymously), is the most common type of behavioral treatment used by many therapists to treat anxiety disorders (Kircanski, Mortazavi, Castriotta, Baker, Mystkowski, Yi, & Craske, 2011; Powell, Honey & Symbaluk, 2013, p. 206).  Systematic desensitization is also considered a form of counterconditioning, and has been used to help individuals adjust their thinking about the feared object or situation and learn more acceptable, “rational” responses.  This therapeutic technique is based on principles of classical and operant conditioning, and it works especially well when paired with cognitive behavioral therapy (CBT) (Triscari, Faraci, D’Angelo, Urso, & Catalisano, 2011)).

From a behavioral perspective, a phobia is a maladaptive behavior in which a pattern of avoidance is developed around a perceived threat.  Phobias are learned in that a previously neutral stimulus, e.g., a dog, paired with a negative experience, e.g., being bitten or witnessing someone else being attacked by a dog, transforms the neutral stimulus into a conditioned stimulus wherein any time a person encounters the conditioned stimulus, they will experience fear.  Because the person fears a certain object or situation, they begin to avoid coming into contact with it, which reinforces the phobic behavior.

Since a phobia is learned, it is believed that “un-learning,” or counterconditioning, the phobia is possible.  A person with a phobia will experience extreme anxiety or a panic attack when exposed to the specific object or situation that is feared (Sue, Sue & Sue, p. 126).  Phobias are conditioned responses that reinforced by persistent avoidance of the feared object (p. 130).  An individual suffering from a phobia has paired a stimulus with a negative response, and overgeneralizes a fear response to that stimulus.  The Diagnostic and Statistical Manual of Mental Disorders (DSM) lists three subcategories of phobias, which are agoraphobia, social phobias, and specific phobias.  Though there is debate among mental health professionals regarding the etiology of phobias, most can agree that systematic desensitization is one of the most effective treatments for phobias, regardless of cause (Powell, et al., p. 201; Lang & Lazovik, 1963).  Flooding therapy is considered effective, however, it is more controversial in that if not utilized properly, it could cause medical complications due to stress and exacerbate fears further (Powell, et al., p. 206).  For treatment of phobias, systematic desensitization is preferred by some due to its gentler approach.

Systematic desensitization is, specifically, the pairing of muscle relaxation with the feared stimulus over time in ascending difficulty, until the anxiety towards the feared stimulus is reduced (Sue, et al., p. 132).  It is based on principles of classical conditioning in that it allows an individual to pair a more rewarding feeling, or positive reinforcement, with a stimulus that is regarded as negative, which eventually changes the way the individual views the negative stimulus.  Because it is a gradual progression across a hierarchy, involving many steps, it is seen as a corrective learning experience (Kircanski, et al., 2012).  It was popularized by Joseph Wolpe, a researcher in graduate school, who hypothesized that exposure to phobic stimulus paired with muscle relaxation techniques could help eliminate phobias, as a form of counterconditioning (Powell, et al., p. 202).  Wolpe derived many of his techniques and ideas from the work of Mary Cover Jones, who performed some of the earliest empirical studies on desensitization as a cure for phobias (Jones, 1924).  However, Jones was not the first to study the conditioning and counter-conditioning of phobias.

The first empirical study conducted to test phobia conditioning and extinction was carried out by John Watson in 1920 (Beck, Levinson & Irons, 2009; Watson & Rayner, 1920).  This experiment involved conditioning an 8-month old boy (“Little Albert”) to fear a neutral stimulus, i.e., a laboratory rat, by pairing the unpleasant sound of striking a suspended steel bar whenever the boy touched the rat (1920).  Soon thereafter, the boy began to show signs of fear and distress whenever the rat was present, demonstrating that he had been conditioned to fear the previously neutral stimulus (1920).  The boy’s fear eventually was generalized to the extent he would cry or move away whenever presented with anything resembling the small, white rodent, i.e., fur coats, rabbits, dogs.  Watson believed that “directly conditioned emotional responses as well as those [generalized] persist, although with a certain loss in the intensity of the reaction, for a longer period than one month.”  (Watson & Rayner, 1920)  Before Watson could counter-condition the induced phobia, Little Albert was removed from his immediate access.  He hypothesized that Little Albert’s fears would persist indefinitely, unless he was counter-conditioned (1920).  Two of the methods he had proposed for counter-conditioning included flooding, as in “Constantly confronting the child with those stimuli which called out the responses in the hopes that habituation would come in corresponding to ‘fatigue’ of reflex,” and systematic desensitization, “By trying to ‘recondition’ by feeding the subject candy or other food just as the animal is shown” (1920).

The techniques developed by Watson, Jones and Wolpe were derived from basic classical conditioning techniques that were made famous by physiologist Ivan Pavlov’s conditioning experiments.  Pavlov extensively studied the physiology of digestion and circulation systems of animals, but later noticed that dogs would salivate whenever a bell was rung before food was presented and explored the connection between the psyche and physiology (Samoilov, 2007).  In 1899, he noted that “in the psychology of salivatory glands discovered by us, we see all the elements of what is called the activity of the soul — feelings, desires, the thoughts about the qualities of the oral content” (as cited by Samoilov, 2007).  Pavlov challenged the views of his peers (and his wife) at the time that there was no connection between physiology and psychology, and set up the experiments that became an important step in the advancement of psychology.

At the time, Pavlov did not consider psychology an “exact science” and insisted on using physiological terminology.  Eventually he and his staff integrated psychological terminology into their work, coining new terms such as “conditional” (learned responses) and “unconditional reflexes” (natural responses) (2007).  These came to become principles of classical conditioning.  This contribution to the study of psychology paved the way for scientists and psychologists to expound on Pavlov’s theories, thus developing the conditioning and counterconditioning techniques that are used today, known as variants of systematic desensitization and exposure therapy.

Because of Pavlov’s initiative in connecting physiology and empirical scientific methods with psychology, important discoveries were made.  When further studies were conducted on “conditional reflexes and structural lesions in central nervous system […] it was concluded that under natural conditions, temporal relationships are established between the centers with the highest degree of plasticity” (2007).  The brain’s plasticity in relation to conditioning was evidence of the direct connection between psychology and physiology in that that learning happens physiologically, and can be observed physically in the brain.  If not for Pavlov, this correlation might not have been made at that time, and the field of psychology might not have been taken as seriously by scientists such as Wolpe.

In the decades following Wolpe’s work, some researchers had derived principles from Watson’s, Jones’s, and Wolpe’s experiments, pairing various elements along with systematic desensitization techniques to reduce fear.  In the 1960’s, some researchers used the traditional methods of pairing the feared object with deep muscle relaxation,[i] but additionally applied hypnotism to induce a calmer state (Lang, et al. 1963).  The researchers had 24 participants with a snake phobia create an “anxiety hierarchy” wherein various situations involving snakes were rated from least frightening to most frightening (1963).  The participants were then trained in deep muscle relaxation, which they were to practice at home routinely.  Once the participants were trained, they began 11 sessions of systematic desensitization.  At the beginning of each session, the participants were hypnotized and told to relax, and then imagine the least distressing item on the hierarchy (1963).  After progressing through each item on the hierarchy throughout the 11 sessions, most participants were able to touch and hold a snake with much less anxiety in the end.  It was determined that systematic desensitization was highly effective in “unlearning” phobias, however, hypnosis and psychoanalysis was not necessarily effective (1963).  The researchers noted that “The unlearning of phobic behavior appears to be analogous to the elimination of other responses from a subject’s behavior repertoire” (1963).  Since this time, many empirical studies have been conducted, showing consistent positive results from using the simple, original method of systematic desensitization to correct phobic behavior.

Furthermore, there are uses for systematic desensitization that are not necessarily phobia related.  It has been used to treat autistic children who have strong reactions to certain auditory stimuli (Koegel, Openden & Koegel (2004).   Autistic children are sometimes known to have ultra-sensitive auditory perception, and sounds such as a running vacuum cleaner or blender might cause them adverse reactions (Stiegler & Davis, 2010).  It is still not known whether autistic children who react negatively to certain otherwise innocuous sounds are reacting in pain or discomfort, or are reacting in fear, but there is evidence showing that autistic children are hyper-aware of external stimulus, such as touch and sound (2010).  Regardless of the cause, the reactions of autistic children can be modified to the extent they become comfortable with the noises (Koegel, et al., 2004).  In one study, a hierarchy was created, similar to other systematic desensitization techniques, and the offending noises were moved gradually closer to the children as they engaged in their favorite activities (2004).  This can be considered a form of classical conditioning in that reflexive reactions are eventually controlled by pairing the unfavorable stimulus gradually with the favorable stimulus, thus allowing the subject to learn a positive association between the two.  Elements of operant conditioning seem to be present, as well, in that the lack of reaction to the loud noises is rewarded with treats, reinforcing the calm behavior.  Because the desensitization was largely successful in reducing discomfort around certain sounds in the autistic children, the study gives evidence that the issue of hypersensitive hearing is most likely a phobic reaction rather than one of pain, and could be modified using counter-conditioning techniques.

Other interesting variables of systematic desensitization have been explored, such as pairing humor with a feared object in one study.  The idea is that “experiencing a feared stimulus in a humorous context may enhance feelings of self-efficacy and one’s willingness to encounter or deal with the feared situation” (Ventis, Higbee & Murdock, 2001).  This could be considered a form of classical conditioning in that it sought to modify reflexive behavior by pairing humor with the feared object, thus “rewarding” the participant with feelings of self-efficacy.  It was found in this study that the addition of humor was not significantly more successful than traditional systematic desensitization.  The researchers remarked that it was not surprising because “systematic desensitization has extensive empirical evidence for its effectiveness” (2001).

It will be interesting to see where the principles of classical conditioning may be applied in the treatment of mental disorders in future studies.  For example, in a qualitative review of various treatments for social phobia, it was determined that systematic desensitization was less effective than cognitive behavioral therapy, but more effective than the use of beta-blockers or placebos (Ponniah & Hollon, 2008).  Compared to agoraphobia, social phobia seems to have been neglected with regard to studies involving systematic desensitization.  With further studies, there may a way to customize desensitization treatment that may be more cost effective than cognitive behavioral therapy for those suffering from social phobia.

At present, there are still skeptics with regard to the practice of psychology, but the work of Pavlov, and those inspired by Pavlov, have contributed to giving it a more empirical and scientific basis for confidence.  Individuals who have benefited from systematic desensitization for treatment of phobias are a testament to the research conducted by scientists who believed there was a way to understand what was previously believed to not be understandable.  With regard to the methods derived from classical and operant conditioning, the extensive studies that have been conducted over the decades suggest that there is little need to use superfluous methods.  The basic conditioning methods derived from Pavlov’s initial discoveries have showed consistent effectiveness.  Many individuals continue to benefit from the systematic desensitization techniques that are still used today by therapists, allowing for improvement of their life quality.

References

Beck, H., Levinson, S. & Irons, G. (2009).  Finding little Albert:  A journey to John B. Watson’s infant laboratory.  American Psychologist, Vol 64(7), Oct 2009, 605-614. doi: 10.1037/a0017234

Coldwell, S., Wilhelm, F., Milgrom, P., Pralla, C. Getza, T., Spadaforaa, A. Chiua, I. Lerouxa, B. Ramsaya, D.  (2007).  Combining alprazolam with systematic desensitization therapy for dental injection phobia.  Journal of Anxiety Disorders 21 (2007) 871-887.  Elsevier Ltd.

Jones, M.C. (1924) A laboratory study of fear:  The case of Peter.  Journal of Genetic Psychology.  100th Anniversary Issue.  Reprinted in 1991 from Vol. 31, No. 4, 308-315

Kircanski, K., Mortazavi, A., Castriotta, N., Baker, A., Mystkowski, J., Yi, R., & Craske, M. (2011).  Challenges to the traditional exposure paradigm: Variability in exposure therapy for contamination fears.  Journal of Behavior Therapy & Experimental Psychiatry, 43 (2012) pp. 745-751

Koegel, Openden & Koegel (2004) A systematic desensitization paradigm to treat hypersensitivity to auditory stimuli in children with autism in family contexts.  Research & Practice for Persons with Severe Disabilities, Vol. 29, No. 2, 122-134

Lang, P. & Lazovik, D. (1963) Experimental desensitization of a phobia.  Journal of abnormal and social psychology.  Vol. 66, No. 6, 519-525.

Ponniah, K. & Hollon, S. (2008) Empirically supported psychological interventions for social phobia in adults: a qualitative review of randomized controlled trials.  Psychological Medicine, Vol. 38, Issue 1, January 2008, pp. 3-14

Powell, R., Honey, P.L., & Symbaluk, D. (2013), Introduction to learning and behavior (4th ed.) Wadsworth, Cengage Learning. (citing Spiegler & Guevremont, 2010)

Samoilov, V. (2007) Ivan Petrovich Pavlov (1849-1936).  Journal of the History of Neurosciences, 16:74-89

Stiegler, L., & Davis, R. (2010) Understanding sound sensitivity in individuals with Autism Spectrum Disorder.  Focus on Autism and Other Develomental Disabilities, 25:67, originally published online (taken from http://foa.sagepub.com/content/25/2/67 on 5/23/13)

Sue, D., Sue, D.W. & Sue, S. (2010) Understanding abnormal behavior.  Wadsworth, Cengage Learning, pp. 126, 130

Triscari, M., Faraci, P., D’Angelo, V., Urso, V., & Catalisano, D. (2011) Two treatments for fear of flying compared:  Cognitive behavioral therapy combined with systematic desensitization or eye movement desensitization and reprocessing (EMDR) Aviation Psychology and Applied Human Factors, Vol. 1(1):9–14; DOI: 10.1027/2192-0923/a00003

Watson, J. and Rayner, R. (1920) Conditioned emotional reactions.  Journal of Experimental Psychology, 3(1), 1-14

Ventis, W.L., Higbee, G. & Murdock, S.A. (2001) Using humor in systematic desensitization to reduce fear.  The Journal of General Psychology, 128(2), 241-253.


Footnotes


[i] Deep Muscle Relaxation was a technique developed by Dr. Edmund Jacobson in the 1920’s.  It involves tensing various muscle groups and then releasing the tension, and teaches individuals how to control the tension in their muscles.

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