Читать книгу Introduction to Abnormal Child and Adolescent Psychology - Robert Weis - Страница 118

Parsimony is the scientific principle that we should provide the simplest explanation for behavior possible. The principle of parsimony is sometimes referred to “Occam’s razor” after the medieval philosopher William of Occam who argued that simpler explanations should be selected over more complex explanations (Lilienfeld, 2018).

The current debate over a therapy called eye movement desensitization and reprocessing (EMDR) illustrates the scientific principle of parsimony. EMDR is used to treat people exposed to trauma. According to EMDR practitioners, when someone experiences a traumatic event, he or she might have difficulty processing the experience and integrating it into memory. As a result, stimuli that are similar to the trauma can trigger unwanted memories, emotions, or sensations. For example, a child who is attacked by a dog might have flashbacks about the attack when he hears a dog bark. Supporters of EMDR assert that flashbacks and other symptoms can be reduced by helping clients process and integrate traumatic experiences into their long-term memory (Shapiro & Laliotis, 2015).

To integrate traumatic memories, EMDR therapists ask clients to remember and describe aspects of their traumatic experience. This procedure is a form of exposure therapy in which the client deliberately thinks about the traumatic event. Then, the client performs a series of bilateral eye movements by following the therapist’s finger or another moving target back and forth across the visual field for several seconds. The eye movements resemble spectators at a fast-paced tennis match, following the ball back and forth with their eyes. The procedure repeats several times until the client’s anxiety dissipates.

There is some evidence that EMDR is effective in reducing posttraumatic stress in adolescents and adults. However, scientists do not agree on how it works. EMDR practitioners have offered several explanations. Some have suggested that the rapid eye movements used in EMDR mimic the eye movements during sleep. Others have suggested that the back-and-forth movement of the eyes increases interaction between the left and right hemispheres of the brain. Still others have posited that eye movements boost a person’s memory (Shapiro & Laliotis, 2015).

However, some scientists wondered whether the rapid eye movements—the hallmark of EMDR—are necessary for treatment. To test their importance, researchers examined children who experienced anxiety and mood problems following a traumatic event, such as a fire or explosion. Some children received traditional EMDR, whereas others received exposure therapy alone, without the rapid eye movements. Results showed that children in both groups had similarly good outcomes. However, adding rapid eye movements to exposure therapy led to only small improvements beyond exposure therapy alone (Rodenburg, Benjamin, de Roos, Meijer, & Stams, 2009).

Several researchers have concluded that EMDR works simply by exposing clients to memories of the trauma until their anxiety decreases. Occam’s razor directs us to select this more parsimonious explanation over more complex alternatives (Jeffries & Davis, 2014). Indeed, exposure therapy is considered a first-line treatment for children with trauma-related disorders and anxiety (Higa-McMillan, Francis, Rith-Najarian, & Chorpita, 2017).