Siegel was also drawn to studying the brain because he wanted to know how attachment—whether in infancy and early childhood or later relationships, including therapy—actually affected human neurobiology. How did attachment contribute to neural integration, encouraging cohesion between various mental processes, like cognition and emotion, that engendered in people the capacity to "make sense" of their own past and tell coherent, meaningful stories about their childhood years? Most important, how might therapy promote this astonishing cross fertilization between "external" relationships and "internal" neural processes?
In 1999, in The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are, Siegel himself addressed the question of how therapy might incorporate both attachment principles and the growing knowledge of brain science. Integrating many strands of knowledge (attachment research, neurobiology, cognitive science, developmental psychology, complexity theory), the book made the case for what Siegel termed "interpersonal neurobiology"—the idea that social relationships fundamentally shape how our brains develop, the way our minds construct reality, and how well (or badly) we adapt to psychological stressors throughout life. He proposed that the oil that greases the gears of this grand, interpersonal neurobiological system is emotion—it's through the communication of emotion that attachment experiences organize the brain. That an emotionally rich connection with a therapist can also change both brain and mind seemed axiomatic to him. But according to Siegel, the particular clinical model or approach used was much less important than the attunement of the therapist to what he called the "critical micromoments of interaction" with the client—including tone of voice, facial expression, posture, motion, eye gaze—that "reveal otherwise hidden states of mind." According to Siegel, the most important element in an attachment-based, neurobiologically savvy therapeutic approach was the requirement "that the therapist feel the feelings, not merely understand them conceptually." This was, in a sense, a hands-on, body-on, mind-on therapy, in which the therapist's whole self vibrated like a tuning fork to every quiver in the client's being without, however, losing the basic emotional stability that the client needed to help regulate his or her own runaway emotions.
While there are no formal protocols, no standardized techniques or formal methodology for "doing" attachment-based therapy, over the years, some general maxims have emerged informally for bringing attachment issues deep into clinical work. Perhaps four of these maxims, or conditions for therapeutic change, upon which probably most attachment-oriented therapists would agree are: (1) Insecure, ambivalent, avoidant, or disorganized early attachment experiences are real events which can substantially and destructively shape a client's emotional and relational development (the client's adult problems don't originate in childhood-based fantasies). (2) The attachment pattern learned in early childhood experiences will play out in psychotherapy. (3) The right brain/limbic (unconscious, emotional, intuitive) interaction of the psychotherapist and client is more important than cognitive or behavioral suggestions from the therapist; the psychotherapist's emotionally charged verbal and nonverbal, psychobiological attunement to the client and to his/her own internal triggers is critical to effective therapy. (4) Reparative enactments of early attachment experiences, co-constructed by therapist and client, are fundamental to healing.
This isn't psychotherapy for the fainthearted. The therapist must stay present, not only to the client's emotions, but also to her own. This may sound suspiciously like the familiar, old rubric, "be aware of transference and countertransference," but it actually calls for something tougher to do than merely intellectually perform that task. In attachment-based therapy, the therapist is asked to stay in the right brain, fully experience the client's feelings, no matter what comes up for her or what raw emotion is triggered from her own history. In other words, the therapist isn't just an observer of the client's emotional journey or even a disinterested guide, but a fellow traveler, resonating with the client's sadness, anger, and anxiety. Rather than recoiling from the intensity of the client's experience, the therapist is providing—through voice tone, eye contact, expression, posture, as well as words—the stability, the ballast, so to speak, to keep the client feeling not only understood, but safely held and supported. Obviously this kind of demanding work, more than some other modalities, requires therapists to have their own inner act together. "We are the tools of our trade, the primary creative instrument with which we do the work," says California clinical psychologist David Wallin, author of Attachment in Psychotherapy. Our ability to use ourselves effectively in this intense work is therefore inhibited by our own core emotional vulnerabilities. As Wallin has written, "If in childhood a certain quality of expression such as anger cannot be felt or experienced, then we cannot relate to this expression in a patient."