An Integrative Review of the Right-Brain Mechanisms of Sandplay Therapy

This paper presents a conceptual and theoretical examination of the key therapeutic factors of sandplay therapy, integrating them with right-brain mechanisms in a conceptual diagram, and summarizes their clinical implications. First, based on developmental neuroscience and attachment theory, the core functions of the right brain—nonverbal emotional processing, symbolic and imaginal understanding, sensory integration, interpersonal coregulation, attachment-based affect regulation, and unconscious emotional processing—are briefly reviewed. Next, previously identified therapeutic factors—experiential factors (self-exploration, emotional stability, therapeutic function), relational factors (co-transference, emotional connection), and symbolic–spiritual factors (play, symbol, meditation)—are systematically aligned with the developmental and neurobiological functions of the right brain to construct an integrated framework. Sensory–symbolic processes involving sand, water, and figurines are shown to activate right-brain mechanisms (nonverbal emotional processing, sensory–symbolic integration, interpersonal coregulation, attachment-based affect regulation, unconscious processing). Through nonverbal affective exchanges, therapist–client right-brain-to-right-brain synchronization (therapeutic alliance, mother–infant oneness, intersubjectivity, co-transference) emerges, leading to healing outcomes such as emotional stabilization, individuation, self-realization, and wholeness. These experiences, in turn, deepen and reinforce right-brain mechanisms through feedback loops. In conclusion, we propose that sandplay therapy can be conceptualized as a right-brain-based depth psychotherapy that contributes to the restoration of emotional stability, the strengthening of the ego–self axis, and the facilitation of the individuation process. By integrating neuroscientific evidence, this study provides therapeutic grounding for sandplay therapy and offers a conceptual framework for clinical application.