Extinción de la personalidad

In 1989, Shapiro discovered quite by chance that rapidly moving one’s eyes while thinking of arousal-based memory lessened the anx-iety associated with that memory for a prolonged time. The discovery was made as part of a personal experience, and as a psychotherapist, she began to apply a technique that she developed from this experi-ence on her patients with PTSD.¹⁴ Eye Movement Desensitization (EMD), as she called it, entailed the identification of a traumatic memory by the patient associated with the expression of a personal

“negative cognition” (“I am shameful”), followed and replaced by a

“positive cognition” (“I am honorable”). The therapist would then pass her fingers back and forth in front of the patient’s face for ten to twelve cycles while the patient followed them visually and concen-trated on the traumatic memory. Following each trial, the therapist would assess the status of the patient’s distress in relationship to the memory, and the degree of incorporation of the positive cognition. In her 1989 early report, Shapiro claimed remarkable clearing of the negative affective component of the traumatic memory in all of her PTSD patients. As she developed the theoretical basis for her tech-nique, she added the term “reprocessing” to its name (EMDR) based on her conclusion that the technique enhanced the speed of informa-tion processing and facilitated transformainforma-tion within the traumatic memory.

The results of anecdotal studies documenting the apparent efficacy of EMDR began to spread throughout the psychotherapeutic commu-nity and hundreds of therapists have received training in the tech-nique through workshops developed by Shapiro. The eclectic nature of the technique predictably has raised skepticism within the same community as well. Early studies attempting to validate the tech-nique were primarily outcome studies using standardized measures of symptoms and the state of distress before and after treatment. Even

large studies suggest universal short-term improvement in symptoms of hyperarousal, intrusion, and avoidance.¹⁵Follow-up studies sug-gest good retention of therapeutic benefits.¹⁶On the other hand, un-controlled studies have been challenged with the assertion that results could well have been based solely on the placebo effect associated with patient contact, and that outcome studies do nothing to validate the unique therapeutic benefit of the eye movement process itself.

Controlled studies have now been done in EMDR, and give a mixed picture regarding patient benefit and validation of the tech-nique. Several studies have been done comparing EMDR with non-treatment wait list patients with PTSD. Although comparison with a nontreatment group of patients does not negate the placebo effect, EMDR clearly appears to produce substantially more improvement than no treatment over a similar period of time.^16,17Comparison of EMDR to a number of techniques that have not been validated in PTSD (relaxation, biofeedback, active listening, image habituation) suggests that there is either no difference between techniques¹⁸nor su-periority of EMDR.^19,20 Only one randomized and controlled study compares EMDR with a validated treatment technique for PTSD. In comparison with cognitive-behavioral therapy (CBT), this study showed that EMDR was less effective than CBT in reducing PTSD symptoms, both statistically and clinically, and that this disparity was actually more evident at a three-month follow-up.²¹

Another concern raised about the specific technique of EMDR questions the relative roles of the eye movements themselves, the traumatic memory imagery, and the use of negative and positive cog-nitive processes. Shapiro has steadfastly maintained that the eye movements themselves remain the core element of the technique.¹⁴ As a result, researchers have attempted to “dismantle” the various components of EMDR in an attempt to discover the salient therapeu-tic elements. The results have been both startling and confusing. One study suggested that eye movements alone without the cognitive ele-ments of EMDR produced therapeutic benefits comparable to those achieved by the standard treatment protocol.²²Another study using alternate tapping on left and right fingers of the subject showed com-parable clinical efficacy, but less change in measures of autonomic arousal.²³ A third demonstrated no difference between using the EMDR protocol with eye movement or with the eyes fixed, although, compared to a past study by these investigators, EMDR was at least

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as effective as imaginal flooding.²⁴Although these studies cast doubt on the critical nature of the eye movement component of EMDR as maintained by Shapiro, they by no means disprove the efficacy of the entire protocol in comparison to other generally accepted techniques.

Speculation about the physiological mode of action of such thera-peutic modalities proves nothing, but it provides the basis for studies designed to validate it, to dissect its therapeutic elements, and to ap-ply that knowledge to devising ancillary treatments. Shapiro presents the hypothesis that the traumatic event leading to the associated memory is isolated and static because it has never been integrated or processed into an adaptive level. EMDR is physiologically designed to allow that reprocessing to take place.²⁵As we have noted, positron emission tomography (PET) studies in arousal activation in PTSD pa-tients suggest a significant lack of physiological coherence between the cerebral hemispheres in patients with PTSD. Several studies using quantitative EEG (QEEG), and single photon emission computerized tomography (SPECT), also support this concept of impairment of cere-bral hemispheric synchronicity in PTSD, and show preliminary evi-dence for integration and reactivation of metabolically inhibited regions in the left hemisphere by relatively brief treatment with EMDR.^26,27Others have noted that alternate finger tapping and auditory stimuli seem to have an equivalent effect in diminishing symptoms of arousal in PTSD.²⁸

All of these somatic techniques have the production of rhythmic alternating bilateral cerebral hemispheric stimulation in common.

This has led several authors to suggest that this integrative effect on cerebral function may help to restore cortical control of sensitized and kindled limbic and brainstem structures. This process might oc-cur from the top down through facilitation of cortical control of limbic structures,^26,27or from the bottom up, through down-regulation of limbic and brainstem nuclei.²⁸

“Positive cognition” in EMDR and a number of other techniques also appear to play an independent and important role in the thera-peutic process. As noted, positive thinking may produce symptom-atic improvement by itself. Activation of inhibited left hemispheric speech and language centers through repetitive verbalization, espe-cially of a phrase with a positive emotional valence, might well facili-tate bilateral cerebral coherence and integration, and enhance the effects of the accompanying somatic exercise. All of these

hypothe-ses, of course, are speculative at this time. They do, however, point the way to avenues of investigation, both of the validity of EMDR and for the development of similar therapeutic techniques to achieve similar physiological goals. One of the most exciting aspects of this process is the attempt to view and conceptualize trauma therapy in terms of its brain pathophysiology and to approach that physiology as a benchmark for treatment. Another is the recognition that the body plays a critical role in the manifestation and perpetuation of trauma, and may be a potent avenue for accessing and dissipating the core physiology of the traumatic reflex.