ABSTRACT
THE THERAPEUTIC ENCOUNTER Nervous System Co-Regulation, Touch, and Interpersonal Physiology in Medical Massage Therapy
Medical massage therapy is more than the mechanical application of pressure, movement, and stretching to muscles, fascia, and joints; it is also a continuous exchange of sensory and physiological information between patient and therapist. This paper examines therapeutic touch through the neuroscience of mechanoreception, affective touch, autonomic regulation, interpersonal physiological synchrony, and nervous system co-regulation. Particular attention is given to slow, rhythmic manual therapies, including acupressure and table stretching, in which therapeutic movement, sustained contact, breathing, proprioception, and patient feedback may create conditions favorable to sensorimotor co-regulation. This expanded model proposes that changes in pain, muscle guarding, movement, and relaxation cannot always be explained by tissue mechanics alone, but may also reflect changes in sensory processing, perception, motor output, and autonomic regulation. Medical massage therapy can therefore be understood as a dynamic therapeutic encounter in which mechanical treatment, neurological interpretation, and interpersonal responsiveness continuously interact.
Dr. Gregory Lawton
THE THERAPEUTIC ENCOUNTER Nervous System Co-Regulation, Touch, and Interpersonal Physiology in Medical Massage Therapy Gregory T. Lawton, D.C., D.N., D.Ac., N.D. American Health Source Blue Heron Academy of Healing Arts and Sciences 2026
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The Therapeutic Encounter Nervous System Co-Regulation, Touch, and Interpersonal Physiology in Medical Massage Therapy Copyright © 2026 Gregory T. Lawton All rights reserved. No portion of this publication may be reproduced, distributed, transmitted, stored, or used in any form or by any means without the written permission of the copyright holder, except for brief quotations used for educational, scholarly, or review purposes as permitted by law. Published by American Health Source
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EDUCATIONAL DISCLAIMER This publication is intended for professional and educational purposes. It presents scientific concepts and clinical perspectives concerning therapeutic touch, sensory processing, nervous system regulation, and medical massage therapy. It is not intended to replace appropriate medical diagnosis, treatment, or individualized clinical judgment. References to physiological mechanisms should be interpreted within the limitations of the scientific literature cited. First Edition, 2026 Printed in the United States of America
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PREFACE For much of the history of massage and manual therapy, the effects of treatment have been explained primarily through the tissues. We have spoken of muscles being lengthened, fascia being released, circulation being increased, adhesions being reduced, and joints being mobilized. These concepts have provided generations of therapists with a practical language for describing what they observe with their hands. Yet the continuing development of neuroscience invites us to consider a larger question: What if some of the changes we observe beneath our hands cannot be adequately explained by the tissues alone? Every therapeutic touch is also a neurological event. Pressure, movement, stretching, vibration, temperature, and sustained contact generate sensory information. That information is transmitted through peripheral nerves and interpreted within a nervous system that is continuously evaluating the body, the environment, previous experience, expectation, comfort, discomfort, and potential threat. What the therapist does mechanically therefore cannot be completely separated from what the patient experiences neurologically. There is another dimension as well. Massage therapy occurs between people. The therapist is not an instrument applying force to passive tissues, and the patient is not merely an anatomical structure receiving treatment. Both are living, responsive biological organisms continually perceiving and responding to one another. A change in the patient's breathing may alter the therapist's movement. An increase in muscular guarding may cause the therapist to reduce pressure. A slower movement may change the patient's breathing. A change in breathing may subsequently alter movement tolerance. Treatment therefore develops through a continuous series of sensory events, responses, observations, and adjustments. This publication explores that interaction. The purpose is not to replace the anatomical and biomechanical foundations of medical massage therapy. Nor is it to substitute psychological explanations for physical treatment. Rather, the purpose is to expand our model so that mechanics, sensory physiology, motor control, autonomic regulation, pain perception, breathing, therapeutic touch, and 4|Pa ge
interpersonal interaction can be understood as parts of the same clinical encounter. The skilled therapist does more than apply techniques. The skilled therapist listens with the hands, observes the patient's responses, modifies the treatment, and allows the patient's changing physiology to help determine what happens next. In this sense, therapeutic touch becomes a conversation.
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FOREWORD There is an understandable tendency within the manual therapies to search for a single mechanism that explains why treatment works. At different times that mechanism has been described as increased circulation, muscular relaxation, fascial release, trigger point deactivation, neurological inhibition, autonomic regulation, or psychological relaxation. Each explanation may contain part of the truth, but the living human organism rarely responds through only one physiological pathway. Contemporary neuroscience increasingly demonstrates that perception, movement, pain, autonomic regulation, emotion, expectation, and social interaction are deeply interconnected. Touch enters this complex system not simply as mechanical pressure but as biologically meaningful sensory information. This perspective is particularly important for massage therapy because few healthcare interactions involve such prolonged and deliberate physical contact between practitioner and patient. During treatment, the therapist continuously generates sensory information through pressure, movement, rhythm, pace, temperature, voice, breathing, and physical presence. The patient receives and interprets this information while simultaneously producing physiological and behavioral responses that the therapist perceives. Treatment consequently becomes reciprocal. This reciprocity does not require mystical explanations or the assumption that one person's nervous system directly connects with another. It can be approached through established principles of sensory physiology, interpersonal communication, autonomic regulation, motor control, affective touch, and the developing science of interpersonal physiological synchrony. Perhaps most importantly, this perspective encourages the therapist to reconsider the meaning of resistance. When a muscle guards against movement, when breathing changes during pressure, or when a patient withdraws from touch, the therapist is receiving information. The appropriate response is not necessarily greater force. It may instead be a change in pressure, position, rhythm, movement, communication, or time. Such an approach places responsiveness rather than force at the center of skilled manual therapy. 6|Pa ge
The concepts explored in this work therefore point toward a broader understanding of therapeutic touch, one in which the therapist does not merely act upon the patient's body but participates in an evolving sensory and physiological interaction with it.
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INTRODUCTION Human touch occupies an unusual position in physiology. It is simultaneously a physical event, a sensory stimulus, a means of communication, and an interpersonal experience. A hand placed upon the body mechanically deforms the skin and underlying tissues, activates sensory receptors, generates afferent neural activity, and produces an experience that is interpreted within the context of the individual receiving that touch. Massage therapy magnifies this interaction because therapeutic contact is sustained, intentional, and continuously modified. Unlike a brief incidental touch, massage may involve prolonged sequences of compression, movement, stretching, stroking, vibration, sustained pressure, joint movement, and positional change. Each technique produces mechanical effects, but each also generates a changing stream of sensory information. The central nervous system does not respond to this information in isolation. Sensory input is interpreted in relation to other information arriving from the body and environment. Previous experiences, pain, expectation, attention, familiarity, uncertainty, emotional state, and the perceived meaning of an encounter can influence how a stimulus is experienced. The same amount of pressure may therefore be perceived as therapeutic by one patient, uncomfortable by another, and differently by the same patient under different circumstances. This variability presents an important challenge to purely mechanical explanations of massage therapy. If treatment outcomes depended only upon force applied to tissues, similar mechanical stimuli should produce relatively similar responses. Clinical experience demonstrates that they frequently do not. Human beings respond as integrated biological systems rather than passive mechanical structures. The therapist is part of that biological environment. The patient's nervous system receives information not only from the therapist's hands but from the predictability of movement, pace of treatment, vocal tone, communication, breathing, and responsiveness to patient feedback. Simultaneously, the therapist receives information from the patient's tissues, movements, respiration, facial expressions, verbal responses, and protective behaviors. This creates a reciprocal feedback system. 8|Pa ge
The developing study of interpersonal physiological synchrony provides one scientific perspective from which this interaction can be examined. Research has demonstrated that physiological variables in interacting individuals can sometimes exhibit temporal coordination. Related work involving affective touch, autonomic regulation, interpersonal physiology, pain neuroscience, and social co-regulation provides additional mechanisms through which the therapeutic relationship can be considered without suggesting that two nervous systems become directly neurologically connected. These concepts become especially interesting in therapeutic approaches characterized by slow, deliberate movement and sustained contact. Acupressure, slow table stretching, and other meditative forms of manual therapy may combine mechanoreceptive stimulation, proprioception, respiratory rhythm, movement, attention, and interpersonal communication within a highly predictable sensory environment. The therapist can simultaneously monitor changes in breathing, muscular guarding, movement resistance, and behavior and adjust treatment accordingly. The resulting interaction may be understood as a form of sensorimotor coregulation. This perspective also encourages a reconsideration of muscular resistance. Resistance encountered during treatment does not necessarily represent tissue that simply requires greater mechanical force. Some resistance may reflect active protective motor behavior. Pain, anticipated pain, uncertainty, perceived instability, unfamiliar movement, or other sensory conditions may influence muscular guarding. If the nervous system's evaluation of the situation changes, motor output may change as well. The purpose of this work is therefore to examine therapeutic touch within a broader physiological framework. Mechanical tissue effects remain important, but they exist alongside mechanoreception, sensory processing, pain modulation, motor control, autonomic regulation, breathing, affective touch, interpersonal physiology, and the therapeutic relationship. This approach does not require abandoning the traditional hands-on foundations of massage therapy. It asks us instead to examine those foundations more deeply.
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The therapist's hands apply mechanical force, but they also provide a continuous stream of sensory information. The patient's tissues respond to that mechanical stimulus while the nervous system simultaneously receives, interprets, and responds to the sensory experience. The therapist perceives changes in tissue resistance, movement, breathing, guarding, and other patient responses and adapts the treatment accordingly. From this perspective, medical massage therapy is not merely the application of techniques to muscles, fascia, and joints, but a continuously evolving therapeutic interaction involving mechanical forces, sensory processing, neurological regulation, patient perception, and interpersonal communication.
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THE THERAPEUTIC ENCOUNTER Nervous System Co-Regulation, Touch, and Interpersonal Physiology in Medical Massage Therapy Gregory T. Lawton, D.C., D.N., D.Ac., N.D. INTRODUCTION Massage therapy has traditionally been described primarily through mechanical and anatomical models. Pressure is applied to muscles and connective tissues, joints are moved, tissues are stretched, and sensory receptors are stimulated. These physical interactions are important, but they represent only part of what occurs during a therapeutic encounter. Massage therapy also involves a continuous exchange of sensory information between the patient and therapist. The patient responds not only to pressure, movement, and tissue loading, but also to the therapist's rhythm, pace, voice, breathing, confidence, attentiveness, and quality of touch. At the same time, the therapist continually responds to changes in the patient's breathing, muscle guarding, tissue resistance, movement, facial expression, verbal communication, and other indications of comfort, apprehension, or distress. Modern neuroscience provides an increasingly useful framework for understanding this interaction. Research involving interpersonal physiology, autonomic regulation, affective touch, physiological synchrony, pain neuroscience, and social co-regulation suggests that human interaction can produce measurable physiological responses in both participants. Massage therapy provides a particularly interesting clinical example because interpersonal communication occurs simultaneously through sustained physical contact and the more familiar sensory channels of voice, facial expression, posture, movement, and behavior. FROM LIMBIC RESONANCE TO INTERPERSONAL PHYSIOLOGY The term limbic resonance has sometimes been used to describe the apparent ability of one person's emotional state to influence the emotional and physiological state of another. The term provides a useful metaphor, but it can become misleading when interpreted literally. There is no direct anatomical or neurological connection between the limbic system of the 11 | P a g e
therapist and that of the patient. One nervous system does not directly transmit an emotional state into another nervous system. What does occur is an extraordinarily complex exchange of sensory information. Each person produces observable and detectable signals through facial expression, vocal tone, breathing, posture, movement, touch, interpersonal distance, and other forms of behavior. These signals are perceived and processed by the other person's nervous system, where they may influence attention, emotional appraisal, autonomic activity, motor behavior, and conscious experience. The resulting response produces additional signals that return to the first person. Human interaction therefore creates a continuous sensory and behavioral feedback loop. A more scientifically appropriate concept for aspects of this phenomenon is interpersonal physiological synchrony. This refers to temporal relationships that can develop between physiological processes measured in interacting individuals. Research has identified associations involving heart activity, respiration, electrodermal activity, and other physiological variables. Physiological synchrony has been observed between romantic partners, parents and children, therapists and patients, and individuals participating in cooperative or socially engaging activities. Importantly, synchrony does not necessarily indicate empathy, emotional agreement, relaxation, or therapeutic benefit. Its meaning depends upon the circumstances in which it occurs. Nevertheless, the research demonstrates an important principle: human physiology does not operate entirely independently of the social environment. TOUCH AS NEUROLOGICAL INFORMATION The relevance of this concept to massage therapy becomes clearer when touch is considered not simply as mechanical force but as sensory information. When the therapist's hand contacts the patient's body, tissues are mechanically deformed, but sensory receptors are simultaneously activated. The nervous system receives information concerning pressure, movement, vibration, stretch, temperature, position, and potentially threatening or painful stimulation. The biological significance of the technique therefore cannot be determined solely by measuring the amount of force applied to the tissues.
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The skin is a highly specialized sensory organ containing multiple classes of receptors and afferent nerve fibers. Their signals enter the central nervous system and contribute to tactile perception, proprioception, motor regulation, pain processing, autonomic responses, and behavioral adaptation. Consequently, therapeutic touch should be understood as an interaction between mechanical stimulation and neurological interpretation. Research concerning C-tactile afferents has further expanded our understanding of touch. These unmyelinated, low-threshold mechanosensory fibers are found primarily in hairy skin and appear particularly responsive to forms of gentle stroking touch associated with affective and socially meaningful contact. Their activity contributes to the pleasant and emotional dimensions of touch, although the complex experience of affective touch cannot be attributed to a single receptor population. The significance of this research for massage therapy is that the nervous system evaluates more than where contact occurred and how much pressure was applied. It also processes characteristics of touch that contribute to the patient's overall perception of the encounter. THE NERVOUS SYSTEM INTERPRETS THE TREATMENT Every manual therapy technique provides sensory input, but identical sensory input does not necessarily produce identical responses. Pressure experienced by one patient as comfortable and therapeutic may be experienced by another as painful, intrusive, or threatening. A rapid technique may feel invigorating to one individual and unsettling to another. Even within the same patient, an identical technique may produce different responses depending upon pain levels, fatigue, emotional state, previous experiences, expectations, and the circumstances surrounding treatment. This variability illustrates an important neurological principle. The nervous system does not merely receive sensory information; it interprets that information. The response to therapeutic touch emerges from an interaction between the immediate sensory stimulus and the biological and experiential condition of the individual receiving it. Previous pain experiences, learned associations, expectations, attention, emotional state, cultural influences, the therapeutic relationship, and the patient's present physiological condition can all influence how touch is perceived.
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This does not mean that every strong emotional or physiological response during treatment represents the activation of a hidden trauma or unresolved emotional memory. Such an interpretation would extend beyond the available neuroscience. Novel situations can themselves generate substantial autonomic and emotional responses. Previous experience is one influence among many. The clinically important point is that the response belongs to the patient's nervous system and emerges from its interpretation of the entire situation rather than from the mechanical stimulus alone. CO-REGULATION IN THE TREATMENT ROOM The concept of co-regulation provides a useful framework for understanding what occurs between therapist and patient during treatment. Co-regulation refers broadly to the ways interacting individuals influence one another's physiological, behavioral, and emotional states. Within massage therapy this process can occur continuously. Consider a patient who initially demonstrates shallow breathing, elevated muscular guarding, apprehension about touch, and difficulty becoming comfortable on the treatment table. The therapist perceives these responses and modifies the treatment accordingly. Pressure may be reduced, movements slowed, transitions made more predictable, and communication increased. As the patient becomes familiar with the therapist's touch and begins to perceive the treatment as non-threatening, breathing may become slower and deeper, voluntary or protective muscular activity may diminish, and movement may become easier. Those changes are then perceived by the therapist, who modifies the treatment again. The therapist may gradually increase pressure, introduce movement, change positioning, or proceed to another technique. The patient's response provides new sensory information to the therapist, and the therapist's adjustment provides new sensory information to the patient. The therapeutic encounter therefore becomes a reciprocal feedback process. The therapist acts, the patient responds, the therapist perceives the response and adapts, and the patient responds to that adaptation. This sequence may repeat hundreds of times during a treatment session, frequently without either individual consciously identifying every adjustment that has occurred. 14 | P a g e
RHYTHM, BREATH, AND SENSORIMOTOR CO-REGULATION The reciprocal process of co-regulation may be particularly relevant to massage modalities that employ slow, rhythmic movement, sustained therapeutic contact, and coordinated breathing. Techniques such as acupressure and slow table stretching combine cutaneous mechanoreception, proprioceptive input, movement, respiratory rhythm, and interpersonal communication within a predictable sensory sequence. Rather than presenting the nervous system with rapidly changing or disconnected stimuli, these methods can create a coherent pattern of sensory information to which the patient can gradually adapt. Slow therapeutic movement may also allow the therapist to perceive subtle changes in breathing, muscular guarding, movement resistance, and patient behavior and to modify the treatment accordingly. The resulting interaction becomes a form of sensorimotor feedback in which the therapist's movement influences the patient's response and the patient's response determines the therapist's next movement. Breathing may further contribute to this process because respiration interacts continuously with autonomic cardiovascular regulation and provides a natural biological rhythm around which movement can be organized. When therapeutic pressure, stretching, movement, and breathing are coordinated, the patient may experience the treatment as more predictable and controllable. In some individuals, this may contribute to decreased protective muscular activity, altered pain perception, and greater tolerance of movement. These effects should not be interpreted as evidence that the therapist directly controls the patient's autonomic nervous system or that slow techniques invariably produce parasympathetic dominance. Rather, slow rhythmic treatment may create a sensory environment that favors adaptation, attention, predictability, and reciprocal physiological regulation. This may help explain why meditative forms of manual therapy can feel qualitatively different from faster or predominantly mechanical treatment methods. AUTONOMIC REGULATION AND THERAPEUTIC TOUCH The autonomic nervous system participates in many of these responses. Sympathetic and parasympathetic activity contributes continuously to 15 | P a g e
cardiovascular, respiratory, digestive, metabolic, glandular, thermoregulatory, and homeostatic regulation. These systems should not be reduced to the popular idea that the sympathetic nervous system represents stress while the parasympathetic nervous system represents relaxation. Human autonomic physiology is considerably more complex and dynamic. Massage and therapeutic touch can influence autonomic measures under certain conditions. Research has reported changes in variables such as heart rate, blood pressure, respiratory patterns, electrodermal activity, and heart rate variability following various forms of massage and touch. However, results differ according to the population studied, the type and duration of treatment, the physiological variable measured, and the methods used by investigators. It is therefore more scientifically appropriate to state that massage may influence autonomic regulation than to claim that massage simply turns off sympathetic activity or turns on parasympathetic activity. This distinction is clinically important because relaxation itself should not be regarded as a single neurological switch. A patient who becomes quieter, breathes differently, reports decreased pain, or demonstrates less muscular guarding is experiencing a complex change involving sensory processing, attention, perception, motor control, autonomic regulation, expectations, and the interpersonal environment. MECHANORECEPTION, PAIN, AND MUSCLE GUARDING Understanding touch as sensory information also provides an alternative to purely mechanical explanations of changes commonly observed during massage therapy. When tissues are compressed, stretched, moved, or vibrated, peripheral sensory receptors provide afferent information to the central nervous system. That information undergoes processing at multiple levels of the nervous system and may subsequently influence pain perception, autonomic activity, motor output, attention, and the conscious perception of the body. Muscle guarding provides a useful clinical example. Increased resistance encountered by the therapist is sometimes interpreted simply as a tight muscle or shortened fascia that must be mechanically lengthened. In some circumstances, however, increased muscular activity represents a 16 | P a g e
protective motor strategy. Pain, anticipated pain, uncertainty, perceived instability, fear of movement, or unfamiliar touch may contribute to increased motor output. When the sensory environment changes, the motor response may also change. A therapist frequently encounters an area that initially resists pressure or movement but gradually becomes less resistant without progressively greater force being applied. Some of this change may involve the mechanical and viscoelastic properties of tissues, but neurological processes may also contribute. The nervous system may alter its motor output as sensory information changes and the perceived need for protection diminishes. This observation has important implications for clinical technique. Greater resistance does not necessarily indicate a need for greater force. Sometimes the more appropriate therapeutic response is to modify the sensory information being provided. THE THERAPIST AS PART OF THE THERAPEUTIC ENVIRONMENT One of the most significant implications of interpersonal physiology is that the therapist is not merely the person administering a technique. The therapist is part of the patient's sensory environment. Pace, pressure, rhythm, predictability, communication, confidence, attention, breathing, posture, and responsiveness all provide information that the patient's nervous system can potentially use in evaluating the treatment. A hurried, distracted, unpredictable, excessively forceful, or poorly communicated treatment provides a different sensory environment from treatment that is attentive, deliberate, responsive, and appropriately paced. This does not imply that the therapist somehow transfers calmness directly into the patient. Rather, the therapist produces sensory and interpersonal signals that the patient's nervous system detects and interprets. The relationship is also reciprocal. A therapist may unconsciously change breathing, posture, muscular tension, voice, or treatment rhythm in response to an anxious or distressed patient. Experienced clinicians often become highly sensitive to subtle changes in tissue resistance, breathing, movement, and behavior. This sensitivity can be clinically valuable when it remains grounded in observation rather than being interpreted as an ability to directly perceive another person's hidden emotional state. 17 | P a g e
THE THERAPEUTIC RELATIONSHIP AS PHYSIOLOGY The therapeutic relationship is sometimes treated as something separate from the physical treatment, as though technique represents the scientific component of massage and interpersonal interaction represents an additional psychological component. Neuroscience suggests that this distinction is artificial. The therapeutic relationship itself provides sensory information that can influence perception, behavior, motor responses, autonomic regulation, and the patient's experience of pain. This does not diminish the importance of anatomy, biomechanics, pathology, or skilled manual technique. Instead, it places those elements within a more complete biological framework. Massage therapy simultaneously involves mechanical forces applied to tissues, stimulation of sensory receptors, afferent neurological signaling, central processing, motor responses, autonomic regulation, perception, expectation, and interpersonal communication. Touch is therefore simultaneously mechanical, sensory, neurological, perceptual, and relational. CONCLUSION The concept traditionally described as limbic resonance contains an important observation: human beings can influence one another physiologically during interpersonal interaction. Contemporary neuroscience provides more precise concepts for examining this phenomenon, including interpersonal physiological synchrony, interpersonal autonomic physiology, affective touch, and co-regulation. Massage therapy represents an especially interesting example because sustained physical contact occurs within a continuous interpersonal exchange. The therapist's hands provide mechanical stimulation, but that stimulation also becomes sensory information. The patient's nervous system receives and interprets that information according to the immediate circumstances, previous experiences, expectations, physiological state, and therapeutic environment. The patient's response then becomes information for the therapist, who adapts the treatment accordingly. The effectiveness of massage therapy therefore cannot be understood solely by asking what a technique mechanically does to a muscle, fascia, 18 | P a g e
tendon, or joint. We must also consider what sensory information the technique provides, how the nervous system interprets that information, what motor, perceptual, and autonomic responses follow, and how the therapist responds to those changes. The therapeutic encounter is not simply an interaction between the therapist's hands and the patient's tissues. It is an ongoing biological conversation involving touch, perception, physiology, behavior, and two continuously responsive nervous systems.
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GLOSSARY Afferent: A nerve fiber or neural pathway carrying sensory information from peripheral receptors toward the central nervous system. Affective Touch: Touch whose processing includes emotional, pleasantness, motivational, and social dimensions in addition to the physical characteristics of the stimulus. Autonomic Nervous System: The portion of the nervous system involved in the regulation of cardiovascular, respiratory, digestive, thermoregulatory, glandular, metabolic, and other largely involuntary physiological functions. Co-Regulation: The reciprocal process through which interacting individuals influence one another's physiological, behavioral, or emotional states. C-Tactile Afferents: Unmyelinated, low-threshold mechanosensory fibers found primarily in hairy skin and associated with aspects of gentle and affective touch. Electrodermal Activity: Changes in the electrical properties of the skin associated principally with sympathetic regulation of the sweat glands and commonly used as a measure of autonomic arousal. Heart Rate Variability: Variation in the time intervals between successive heartbeats. HRV provides information concerning aspects of autonomic cardiovascular regulation but should not be regarded as a simple measurement of relaxation. Interoception: The sensing and processing of information concerning the internal physiological condition of the body. Interpersonal Physiological Synchrony: Temporal coordination or statistical association between physiological processes measured in two or more interacting individuals. Limbic Resonance: A descriptive concept suggesting reciprocal emotional and physiological influence between individuals. It should not be interpreted as a literal direct neurological connection between two limbic systems.
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Mechanoreceptor: A sensory receptor responsive to mechanical deformation, including pressure, stretch, vibration, and movement. Muscle Guarding: Protective muscular activity that may occur in response to pain, anticipated pain, perceived instability, threat, injury, unfamiliar sensory input, or other conditions. Physiological Synchrony: Temporal coordination between physiological signals measured in interacting individuals. Synchrony alone does not establish empathy, emotional agreement, causation, or therapeutic benefit. Somatosensory System: The sensory systems involved in processing touch, pressure, vibration, proprioception, temperature, pain, and related bodily sensations.
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