fNIRS Hyperscanning of Right-brain Synchronization between Therapist-client in Sandplay Therapy

Abstract

This study investigated inter-right brain synchrony between therapist and client in Sandplay therapy, using hyperscanning technique based on functional near-infrared spectroscopy (fNIRS). fNIRS is a non-intrusive method that measures changes in oxyhemoglobin the cerebral blood. A total of seven therapist-client pairs-i.e., 14 participants-wore fNIRS devices on their heads and engaged in two sessions of Sandplay therapy, with each session lasting for 30 minutes. The study observed synchronization in the right and left prefrontal cortices of both therapists and clients in all seven pairs, during every session. Interestingly enough, synchronization occurred not only while the pairs engaged in verbal communication about the completed sandpicture but also during the non-verbal process of clients' creating sandpictures. The outcome of the study hence suggests neurobiological fundamentals for the therapeutic relationship between therapist and client, which is also called the therapeutic resonance, relational mutual regression, therapeutic alliance, and mother-child unity.