Neurophysiological Correlates of Exposition Therapy in Spider Phobia

Neurophysiological Correlates of Exposition Therapy in Spider Phobia

This study aims to investigate the neurophysiological correlates of spider phobia and its treatment with CBT based Exposure Therapy. This is the first study to investigate the neurophysiological correlates of Exposure Therapy in situ by means of functional Near-Infrared Spectroscopy (fNIRS).

30 spider phobic patients will be assessed and randomly allocated to 5 sessions of exposure therapy or waiting-list. Further, 30 non-phobic control subjects will be assessed (primary assessment only).

During Exposure Therapy, changes in blood oxygenation will be measured with fNIRS in areas of the Cognitive Control Network. Regions of interest are the bilateral dorsolateral prefrontal cortex (DLPFC), bilateral inferior frontal gyrus (IFG) and somatosensory association cortex (SAC). Before the treatment, subjects will have one session of psychoeducation in which the rationale for the treatment is explained. In each therapy session subjects are exposed to 20 trials (each lasting 40s) of guided exposure by a psychotherapist. Further, 20 control trials of equal length are assessed in which subjects work with an earthworm. During the therapy additional anxiety coping strategies (e.g., controlled breathing, attention refocusing, cognitive reappraisal) are trained. After the treatment or waiting-list phase, treatment conditions are switched: The waiting list will be treated and the treated subject will wait for approximately 6 weeks.

Before treatment (primary assessment), after treatment (secondary assessment) and after study completion (final assessment), additional combined NIRS EEG measurements are done. On a peripheral physiological level heart rate and EMG of the facial corrugator supercilii are measured. During these measurements subjects are asked to watch 10s lasting video clips showing spiders (experimental condition) or pets (dogs and cats). On a psychometric level, spider phobia will be assessed by questionnaires (SPQ, FSQ, SBQ) and behavioral assessments.

Inclusion Criteria:

• Spider Phobia or no fear of spiders
• Age between 18 and 50
• normal vision (or corrected with glasses)
• German mother tongue or comparable knowledge

Exclusion Criteria:

• pregnancy
• medication with exception of contraceptive medication
• acute or chronic disease that affects brain functioning (other mental diagnosis than spider phobia, cardial diseases, diabetes, kidney diseases, concussion)