In psychology, desensitization is a treatment or process that diminishes emotional responsiveness to a negative, aversive or positive stimulus after repeated exposure to it. Desensitization also occurs when an emotional response is repeatedly evoked in situations in which the action tendency that is associated with the emotion proves irrelevant or unnecessary. The process of desensitization was developed by psychologist Mary Cover Jones, and is primarily used to assist individuals in unlearning phobias and anxieties. Joseph Wolpe (1958) developed a method of a hierarchal list of anxiety evoking stimuli in order of intensity, which allows individuals to undergo adaption. Although medication is available for individuals suffering from anxiety, fear or phobias, empirical evidence supports desensitization with high rates of cure, particularly in clients suffering from depression or schizophrenia.
The hierarchical list is constructed between client and therapist in rank ordered series of steps from the least disturbing to the most disturbing fears or phobias. Secondly the client is taught techniques that produce deep relaxation. It is impossible to feel both anxiety and relaxation at the same time, so easing the client into deep relaxation helps inhibit any feelings of anxiety. Systematic desensitization (a guided reduction in fear, anxiety or aversion) can then be achieved by gradually approaching the feared stimulus while maintaining relaxation. Desensitization works best when individuals are directly exposed to the stimuli and situations they fear so anxiety-evoking stimuli are paired with inhibitory responses. This is carried out either by clients performing in real life situations (known as vivo desensitization), or, if it is not practical to directly act out the steps of hierarchy, by clients observing models performing the feared behaviour (known as vicarious desensitization). Clients slowly move up the hierarchy, repeating performances if necessary, until the last item on the list is performed without fear or anxiety.
Animals can also be desensitized to their rational or irrational fears. A race horse who fears the starting gate can be desensitized to the fearful elements (the creak of the gate, the starting bell, the enclosed space) one at a time, in small doses or at a distance. Clay et al. (2009) conducted an experiment whereby he allocated rhesus macaques to either a desensitization group or a control group, finding that those in the desensitization group showed a significant reduction in both the rate and duration of fearful behavior. This supports the use of PRT training. Desensitization is commonly used with simple phobias like insect phobia. In addition, desensitization therapy has been shown to be a useful tool in training domesticated dogs. Systematic desensitization used in conjunction with counter-conditioning was shown to reduce problem behaviours in dogs, such as vocalization and property destruction.
Desensitization also refers to the potential for reduced responsiveness to actual violence caused by exposure to violence in the media, although this topic is debated in the scientific literature on the topic. Desensitization may arise from different sources of media, including TV, video games and movies. Some scholars suggest that violence may prime thoughts of hostility, with the possibility of affecting the way we perceive others and interpret their actions.
It is hypothesized that initial exposure to violence in the media may produce a number of aversive responses such as increased heart rate, fear, discomfort, perspiration and disgust. However, prolonged and repeated exposure to violence in the media may reduce or habituate the initial psychological impact until violent images do not elicit these negative responses. Eventually the observer may become emotionally and cognitively desensitized to media violence. In one experiment, participants who played violent video games showed lower heart rate and galvanic skin response readings, which the authors interpreted as displaying a physiological desensitization to violence. However, other studies have failed to replicate this finding. Some scholars have questioned whether becoming desensitized to media violence specifically transfers to becoming desensitized to real-life violence.
Desensitization can refer to:
Desensitization of explosives, see Phlegmatized
Desensitization, Allergen immunotherapy
Desensitization, another name for Exposure therapyFlooding (psychology)
Flooding, sometimes referred to as in vivo exposure therapy, is a form of behavior therapy and desensitization—or exposure therapy—based on the principles of respondent conditioning. As a psychotherapeutic technique, it is used to treat phobia and anxiety disorders including post-traumatic stress disorder. It works by exposing the patient to their painful memories, with the goal of reintegrating their repressed emotions with their current awareness. Flooding was invented by psychologist Thomas Stampfl in 1967. It is still used in behavior therapy today.
Flooding is a psychotherapeutic method for overcoming phobias. This is a faster method of ridding fears when compared with systematic desensitization. In order to demonstrate the irrationality of the fear, a psychologist would put a person in a situation where they would face their phobia at its worst. Under controlled conditions and using psychologically-proven relaxation techniques, the subject attempts to replace their fear with relaxation. The experience can often be traumatic for a person, but may be necessary if the phobia is causing them significant life disturbances. The advantage to flooding is that it is quick and usually effective. There is, however, a possibility that a fear may spontaneously recur. This can be made less likely with systematic desensitization, another form of a classical condition procedure for the elimination of phobias.Habituation
Habituation is a form of non-associative learning in which an innate (non-reinforced) response to a stimulus decreases after repeated or prolonged presentations of that stimulus. Responses that habituate include those that involve the intact organism (e.g., full-body startle response) or those that involve only components of the organism (e.g., habituation of neurotransmitter release from in vitro Aplysia sensory neurons). The response-system learns to stop responding to a stimulus which is no longer biologically relevant. For example, organisms may habituate to repeated sudden loud noises when they learn these have no consequences. Habituation usually refers to a reduction in innate behaviours, rather than behaviours acquired during conditioning (in which case the process is termed "extinction"). A progressive decline of a behavior in a habituation procedure may also reflect nonspecific effects such as fatigue, which must be ruled out when the interest is in habituation as a learning process.Non-associative learning is a change in a response to a stimulus that does not involve associating the presented stimulus with another stimulus or event such as a reward or punishment. (Examples of associative learning include classical conditioning and operant conditioning).
Some related phenomena to habituation include sensitization and stimulus generalization/discrimination. Sensitization is the opposite observation to habituation, i.e. an increase in the elicited behavior from repeated presentation of a stimulus. There may also be an initial increase in response immediately prior to the decline (a sensitization process followed by a habituation process). Another related phenomenon is stimulus generalization, when habituation occurs in response to other stimuli that are similar to the original stimulus. The opposing process, stimulus discrimination, is when habituation does not occur to other stimuli that are dissimilar to the original stimulus. Habituation may also be clinically relevant, as a number of neuropsychiatric conditions, including Autism, Schizophrenia, Migraine, and Tourette's, show reductions in habituation to a variety of stimulus-types both simple (tone) and complex (faces).