Neurobiology of successful exposure therapy in girls

Background: There is a lack of controlled psychotherapy studies, in which electrocortical and electromyographic responses of children suffering from spider phobia have been investigated. It still needs to be demonstrated whether spider-phobic children show similar neurobiological responses during symptom provocation and after successful exposure therapy as adults. Also, it is not clear if the phobic response in children is predominantly fear- based or if disgust plays an equally important role. Method: Participants of the planned study are 40 spider-phobic girls (8 - 11 years old), who are randomly assigned to either a therapy group or to a waiting-list group as well as 20 non-phobic girls. In a first session, the children will be presented with a total of 120 pictures depicting spiders, disgust-inducing, fear-inducing and affectively neutral contents. During the presentation the electroencephalogram (EEG) as well as the facial electromyogram (EMG) of the musculus levator labii (a specific disgust indicator) and the m. corrugator (`frowning muscle`) will be recorded. Afterwards, the children are asked to give affective ratings for the pictures on the dimensions valence, arousal, fear and disgust. Prior to the second session, where the participants will be presented with the same picture set, the therapy group undergoes exposure therapy, whereas the waiting-list group receives no treatment. EEG data will be analyzed according to event-related potentials, which are indicators of motivated attention and affective processing (P300, late positive potential (LPP)). The mothers and fathers of the spider-phobic girls will be interviewed with regard to their spider-phobic symptoms, trait anxiety and disgust sensitivity. Hypotheses: (1) Relative to healthy controls, spider-phobic children show an enlarged late positivity to phobia- relevant relative to neutral stimuli (enlarged P300 and LPP). (2) Successful exposure therapy leads to a reduction of P300 and LPP amplitudes in response to the phobic material. (3) Spider-phobic children are characterized by elevated disgust reactivity. This should manifest itself in more intense disgust ratings for spiders and disgust- inducing pictures, a more pronounced facial disgust expression (EMG levator labii) during the viewing of these pictures and higher trait disgust relative to non-phobic children. (4) An exploratory question addresses the correlation between spider-phobic symptoms, trait anxiety and disgust sensitivity in parents and daughters. It is hoped that the planned study will contribute to a better understanding of spider-phobic symptoms in children and an improvement of psychotherapeutic treatment strategies.

Background: There is a lack of controlled psychotherapy studies, in which electrocortical and electromyographic responses of children suffering from spider phobia have been investigated. It still needs to be demonstrated whether spider-phobic children show similar neurobiological responses during symptom provocation and after successful exposure therapy as adults. Also, it is not clear if the phobic response in children is predominantly fear- based or if disgust plays an equally important role. Method: Participants of the planned study are 40 spider-phobic girls (8 - 11 years old), who are randomly assigned to either a therapy group or to a waiting-list group as well as 20 non-phobic girls. In a first session, the children will be presented with a total of 120 pictures depicting spiders, disgust-inducing, fear-inducing and affectively neutral contents. During the presentation the electroencephalogram (EEG) as well as the facial electromyogram (EMG) of the musculus levator labii (a specific disgust indicator) and the m. corrugator ("frowning muscle") will be recorded. Afterwards, the children are asked to give affective ratings for the pictures on the dimensions valence, arousal, fear and disgust. Prior to the second session, where the participants will be presented with the same picture set, the therapy group undergoes exposure therapy, whereas the waiting-list group receives no treatment. EEG data will be analyzed according to event-related potentials, which are indicators of motivated attention and affective processing (P300, late positive potential (LPP)). The mothers and fathers of the spider-phobic girls will be interviewed with regard to their spider-phobic symptoms, trait anxiety and disgust sensitivity. Hypotheses: (1) Relative to healthy controls, spider-phobic children show an enlarged late positivity to phobia- relevant relative to neutral stimuli (enlarged P300 and LPP). (2) Successful exposure therapy leads to a reduction of P300 and LPP amplitudes in response to the phobic material. (3) Spider-phobic children are characterized by elevated disgust reactivity. This should manifest itself in more intense disgust ratings for spiders and disgust- inducing pictures, a more pronounced facial disgust expression (EMG levator labii) during the viewing of these pictures and higher trait disgust relative to non-phobic children. (4) An exploratory question addresses the correlation between spider-phobic symptoms, trait anxiety and disgust sensitivity in parents and daughters. It is hoped that the planned study will contribute to a better understanding of spider-phobic symptoms in children and an improvement of psychotherapeutic treatment strategies.