Symptom provocation and reduction in patients suffering from spider phobia

Abstract

Neurofunctional mechanisms underlying cognitive behavior therapy (CBT) are still not clearly understood. This functional magnetic resonance imaging (fMRI) study focused on changes in brain activation as a result of one-session CBT in patients suffering from spider phobia. Twenty-six female spider phobics and 25 non-phobic subjects were presented with spider pictures, generally disgust-inducing, generally fear-inducing and affectively neutral scenes in an initial fMRI session. Afterwards, the patients were randomly assigned to either a therapy group (TG) or a waiting list group (WG). The scans were repeated one week after the treatment or after a one-week waiting period. Relative to the non-phobic participants, the patients displayed increased activation in the amygdala and the fusiform gyrus as well as decreased activation in the medial orbitofrontal cortex (OFC) during the first exposure. The therapy effect consisted of increased medial OFC activity in the TG relative to the WG. Further, therapy-related reductions in experienced somatic anxiety symptoms were positively correlated with activation decreases in the amygdala and the insula. We conclude that successful treatment of spider phobia is primarily accompanied by functional changes of the medial OFC. This brain region is crucial for the self-regulation of emotions and the relearning of stimulus-reinforcement associations.

CBT reduces CBF: cognitive‐behavioral therapy reduces cerebral blood flow in fear‐relevant brain regions in spider phobia

“…2007), the finding of reduced CBF in components of the motor cortex and areas associated with language functions is not obvious. The motor cortex appears to play a role in the direct control of behavior and the planning of movement eliciting defensive behavior and action preparedness in response to negative emotional stimuli (Blakemore et al.…”

“…Despite this, during postprocessing of phobia‐relevant stimuli, patients showed reduced CBF in the bilateral insula, which is in accordance with the results of Schienle et al. (2007). Nevertheless, it is important to note that changes in brain response may occur in the absence of clinical changes.…”

“…2003; Schienle et al. 2007). This brain region is crucially involved in self‐regulation of emotions and learning (Schienle et al.…”

“…This brain region is crucially involved in self‐regulation of emotions and learning (Schienle et al. 2007). The MTL, which consists of the hippocampus and parahippocampal gyrus, is involved in the retrieval of declarative and autobiographical memories in humans (Squire 1992; Moser and Moser 1998; Cabeza and Nyberg 2000; de Quervain et al.…”

Brain systems underlying encounter expectancy bias in spider phobia

“…Schienle, Schäfer, Walter, Stark, & Vaitl, 2005), which the authors attributed to the use of metacognitive strategies for the regulation of fear, possibly mediating avoidance behavior. After completion of cognitive behavior therapy, no such activation was found (for further changes associated with cognitive behavior therapy of spider phobia, see Schienle, Schäfer, Hermann, Rohrmann, & Vaitl, 2007). To solve the discrepancy regarding the dlPFC activations in animal phobia, it has been proposed that both non-phobics and phobics use top-down control, but perhaps of different kinds or with different effectiveness.…”