The Role of Oxytocin and Interoception in Functional Neurological Disorder

The RRST measures interoception on the domain of the breath and thus allows its (non-invasive) manipulation. The RRST apparatus includes a step motor that moves a wedge piece back and forth to change the obstruction level in the breathing circuit. This fully automated apparatus will change the breathing obstruction level via a computer-controlled algorithm. The patient breath by the month though this device.

The HBT measures interoception on the domain of the cardiovascular system, by assessing how accurate participants perceive their own heartbeat. After each time window participants will be asked how many heartbeats they counted, which will be compared to the actual heartbeat measured via electrocardiography (ECG).

The HEP is computed by averaging EEG signals time-locked to specific peaks of simultaneously measured ECG signals. Therefore both an ECG and an EEG will be set up for the participants. The task during the HEP is to simply focus on interoceptive tones (the own heartbeat) with a control condition of focusing on exteroceptive tones (sounds played). A further condition of HEP measurement is the cardio-audio synchronization. Hereby, participants will be instructed to passively listen to sounds presented to them via in-ear phones while further fixating the cross.

Additionally we also link the interoceptive domain of the breath to a well-known and established agency task measuring conscious intention. Participants will do two versions of the Libet taks while simultaneously recording their EEG and breathing signals with a respiratory belt.