The Neuroscience of Lifespan Integration

By Peggy Pace

Lifespan Integration (LI) is a revolutionary form of psychotherapy developed during the first years of the 21st century. LI combines new developments in neuroscience and self-organizing systems with the psychology of attachment and with archetypal psychology.

When, in 2002, I discovered how to use my clients’ life narratives in a way that seemingly changed their neural organization and structure, I began to study the developments in neuroscience which had emerged during the 1990’s. This article summarizes my hypotheses about the neurobiological basis of Lifespan Integration, originally described in my 2003 book: “Lifespan Integration: Connecting Ego States through Time”. Over the past fifteen years many Lifespan Integration psychotherapists have carried out their own informal investigations, using various scales to test their clients before and after LI therapy. The exact neuroscience of how our nervous systems integrate new information is still largely unknown, however the results of the official research studies of Lifespan Integration and the observations of thousands of trained LI clinicians continue to support my original theory of how and why LI works. More information about the published research is available on this website under “About LI” > “Research”.

The human body-mind is a complex self-organizing system which, like all self-organizing systems, follows certain rules. Self-organizing systems spontaneously reorganize under certain conditions. Reorganization of a self-organizing system is not a process of building one layer upon another, but rather requires the system to come apart and restructure. This happens in discreet quantum shifts. Each of these shifts brings more coherence and more efficient functioning to the system. For optimal results when using LI we need to understand how to create the optimal conditions for neural reorganization. We want to create conditions which will move our clients out of homeostasis just long enough for their self-systems to reorganize. In order to gently push each client’s self-system to reorganize, we need to create conditions which optimize neural plasticity. These conditions are focal attention, optimal emotional activation, and repetition. Hebb’s rule is most commonly summarized as: “Neurons that fire together wire together.” More neurons fire when we are interested and engaged, with our attention focused on the task at hand. Midrange emotional activation also increases neural plasticity. Each repetition of the client’s Timeline reinforces the firing patterns of the involved neural networks and continues to connect those networks to other parts of the client’s self-system. Maximizing repetitions of the Timeline during each session of LI reinforces neural firing patterns and promotes integration between neural networks. Repetitions also serve to push the client’s self-system through more and more state shifts, eventually pushing the system to reorganize itself into a more stable and coherent structure with a more efficient level of functioning. Allan Schore (2003) tells us that “The stability of a system is dependent upon its capacity to transition between and thereby exist within a range of possible states…”

Each memory is thought to be a particular firing pattern of neurons and connections between neural networks; therefore each memory corresponds to a self ‘state’. If the therapist holds the client within their Window of Tolerance (WOT) while leading the client through all the state shifts brought about by repetitions of the LI Timeline, this alone will bring about more stability in the client’s self-system. While leading clients on multiple ‘tours’ through their Timelines, we are at the same time ‘pushing’ them through thousands of state shifts while simultaneously ‘loading’ their body-minds with enough energy and information to force a shift to a new level of organization. Large shifts in neural states can be disruptive. These large shifts are sometimes evident when clients’ bodies jerk slightly while going from one memory cue to another. When working with clients with fragmented self-systems, therapists must take extra care to limit how much material is activated and to maintain clients within their WOTs. Too much activation can cause neural disorganization without the aimed for reorganization. Neural reorganization occurs when clients are within their WOT’s.

The therapist’s attunement and feedback during the process allows the quantum shifts of LI therapy to take place in the gentlest way possible. During and between repetitions, the therapist ‘contains’ the ‘material’ which comes up for the client, and gives input as needed. The input which the therapist suggests between repetitions can be informational – for example: “It is over” or “You are here now” or it can be proposed imaginal activity – for example: “Imagine that you are holding your younger self and looking into her eyes.” Brain scans have shown that imagined actions light up the same neural circuitry in the brain as do the actions themselves. The therapist’s brief statements and coached imaginal interventions during and between repetitions of the client’s Timeline are effective at calming clients and maintaining them within their WOTs.

The coherence of the LI therapist’s self-system and the therapist’s ability to stay attuned to the client during LI sessions is another critical factor for effective LI therapy. The therapist must be capable of self-regulation and must be able to ‘hold’ or ‘contain’ the material which comes up for the client during the LI session. Allan Schore (1994) tells us, “The brain is a self-organizing system which, during early development, organizes itself through interactions with the primary caregiver.” Daniel Siegel (1999) tells us that neural integration within a developing child occurs through the co-construction of the child’s autobiographical narrative. This co-construction usually occurs over time within the parent-child dyad, beginning at about age two. It appears that the same dynamic plays out within the therapist-client dyad during LI sessions, without the therapist needing to know the details of the client’s life narrative. Attachment research shows that securely attached individuals have coherent life narratives, are better able to self-regulate, and raise their children to become securely attached adults. We find that securely attached therapists with coherent self-systems get significantly better results using LI than do less coherent therapists.

The increasing coherence within clients’ self-systems which we observe as a result of Lifespan Integration therapy, is reflected in their improved ability to regulate their emotions, and in the increased coherence in their autobiographical narratives. During the course of their LI therapy, clients often realize that some of the memories they had written on their memory cue lists had originally been listed in the wrong order. As their therapy progresses, they adjust their cue lists, improving the accuracy of the chronology, and often filling in memories where previously there were gaps. Daniel Siegel (1999) says “the capacity of the mind to create such a global map of the self across time and various contexts – to have autonoetic consciousness – is an essential feature of integration that may continue to develop throughout life.” Siegel goes on to say: “Integration is not a function of the self. It is what the self is.”

In 2020, as I summarize the neuroscience of LI, our understanding about the functioning of our nervous systems and brains is still limited. We do not fully understand how energy and information are exchanged between people within relationships. We do not fully understand how memory is stored and reconstituted within our body-mind systems. Neuroscientists are still trying to understand the puzzle of consciousness – what consciousness is, where it resides, and who we are. Spiritual traditions have been asking these same questions for millennia. Our tools for studying the brain and nervous system have come a long way in the past thirty years yet are still quite primitive. We may never have all the answers, and perhaps we don’t need them.


Schore, A.N. 1994. Affect regulation and the origin of the self: The neurobiology of emotional development. Hillsdale, NJ: Lawrence Erlbaum Associates.

Schore, Allan N. 2003. Affect dysregulation and disorders of the self. New York, NY: W.W. Norton and Company, Inc.

Siegel, Daniel J. 1999. The developing mind: Toward a neurobiology of interpersonal experience. New York, NY: The Guilford Press.