Are Over-coupling and Clustering the Same Thing? And Is Under-coupling Just Dissociation by Another Name? A Trauma Therapist’s Perspective
In trauma therapy we’re often working across models SE, EMDR, polyvagal theory, hypnosis, somatics, attachment science. And because each modality evolved its own language, the concepts can look similar on the surface but feel different once you’re actually in the room with a client.
A question that comes up repeatedly for me, clinically and in supervision, is:
Are SE’s ideas of over-coupling and under-coupling essentially the same as EMDR’s clustering and dissociation? And if not - how do they differ?
This matters, because accurate conceptualisation changes clinical decision-making, pacing, titration, and how we support clients to stay within their window of tolerance.
SE’s Map: Over-coupling and Under-coupling
Somatic Experiencing frames trauma as a disruption in the integration of experience - sensations, emotions, images, impulses, and narratives no longer move together fluidly. Instead, they become either too tightly fused or too disconnected (Levine, 1997; Payne, Levine & Crane-Godreau, 2015).
Over-coupling: When Too Much Links Together
In over-coupling, the nervous system binds unrelated cues into a single threat network.
The classic examples:
A bearded person → instant autonomic activation
A facial expression → a belief of danger before any conscious appraisal
An internal sensation → immediate meaning (“my heart racing = I’m not safe”)
What is important here is the rigidity. There is no flexibility or curiosity; everything moves as one chunk. The system has learned that survival depends on rapid, global mobilisation.
Under-coupling: When Experience Fragments
Under-coupling is the opposite problem: elements that should be linked drift apart.
This can look like:
Numbing
Flat affect
Losing the thread of the narrative
Feeling “far away”
Low interoceptive awareness
No emotional response to a clearly emotional memory
Under-coupling protects the system from overwhelm - it is a functional adaptation. But it reduces coherence, presence, and access to the felt sense.
It’s bigger than dissociation, though dissociation lives in this territory.
EMDR’s Map: Clustering and Dissociation
EMDR conceptualises trauma as memory networks that have been maladaptively stored and fail to link with adaptive information (Shapiro, 2001, 2018). When a target activates, other associated networks often “light up” with it.
Clustering: When Networks Activate as a Bundle
Clustering isn’t precisely the same as over-coupling, but the overlap is strong:
One memory activates → several others activate with it.
Affect, body sensations, and core beliefs all surge together.
Themes reappear across targets despite different life chapters.
Clinically, this is when a simple target suddenly becomes complex, layered, and emotionally dense. It’s not that the networks are fused the way SE describes - but they are linked enough that processing one requires care and pacing.
Dissociation: A Spectrum, not a Category
In EMDR, dissociation is a continuum (Lanius et al., 2010):
Mild detachment
Emotional numbing
Depersonalisation / derealisation
Identity or time fragmentation
Parts-based dissociation
Autonomic shutdown or collapse
Dissociation can certainly manifest as under-coupling - but under-coupling includes many subtle disconnects that never reach full dissociative states.
So, Are These Concepts Actually the Same?
Ove-coupling vs Clustering
They are related but distinct.
Over-coupling (SE)
· Sensory, emotional, and cognitive elements become fused
· Results in rigid, global activation
· Bodily-based survival learning
Clustering (EMDR)
· Memory networks activate together
· Results in thematic activation
· AIP-based network activation
Both describe the “stickiness” of trauma. Both indicate a system primed for over-association.
But SE is describing the somatic fusion, whereas EMDR is describing memory-network activation patterns.
Under-coupling vs Dissociation
Also related - but not interchangeable.
Under-coupling (SE)
· Broad category of disconnect
· Can be mild (low feeling, low sensation, fragmentation)
· About lack of integration
Dissociation (EMDR)
· Specific psychological and neurobiological defence
· Can be mild to severe (shutdown, parts, loss of time)
· About altered states of consciousness
All dissociation involves under-coupling.
Not all under-coupling is dissociation.
This distinction is vital. I often see clients who describe themselves as “dissociating” when actually they are experiencing a much milder form of under-coupling - low affect, poor interoception, or cognitive disconnection. Labelling everything as dissociation can increase fear and pathologize adaptive autonomic strategies.
Why This Distinction Matters in Practice
As therapists, we’re constantly assessing:
How activated is the client?
How integrated is their experience?
Where is their self-capacity right now?
Are they in sympathetic charge, dorsal drift, or oscillating?
And this informs our pacing.
If the client is over-coupled / clustered:
Slow the process.
Titrate activation.
Resource and orient
Keep attention narrow and contained.
Work micro-moment to micro-moment.
In EMDR, consider sequencing and interweaves.
If the client is under-coupled / dissociatively leaning:
Strengthen presence.
Increase sensory contact.
Build interoception.
Use grounding and anchoring.
Establish dual attention before reprocessing.
Work with parts if needed.
In EMDR, use dissociation-informed protocols (e.g., Fraser’s table, limited BLS)
These distinctions make the work safer, more attuned, and more effective -especially for complex trauma, neurodivergence, FND, or clients with chronic over- or under-activation.
In Summary - The Maps Are Different, but the Territory Is the Same Nervous System
Somatic Experiencing and EMDR are describing similar adaptive patterns through different lenses:
SE speaks the language of sensation, organismic response, and autonomic coupling.
EMDR speaks the language of memory networks, information processing, and dissociation.
Understanding both maps allows us, as clinicians, to meet clients where they are with nuance, confidence, and clinical flexibility.
Key References
Levine, P. (1997). Waking the Tiger: Healing Trauma. North Atlantic Books.
Levine, P. (2010). In an Unspoken Voice: How the Body Releases Trauma and Restores Goodness. North Atlantic Books.
Payne, P., Levine, P. & Crane-Godreau, M. (2015). Somatic Experiencing: Using interoception and proprioception as core elements of trauma therapy. Frontiers in Psychology, 6, 93.
Shapiro, F. (2001). EMDR: Basic Principles, Protocols and Procedures. Guilford Press.
Shapiro, F. (2018). EMDR Therapy (3rd ed.). Guilford Press.
Lanius, R. et al. (2010). The neurobiology of dissociation: Understanding altered states of consciousness. Acta Psychiatrica Scandinavica, 121(3), 167–177.
Ogden, P., Minton, K., & Pain, C. (2006). Trauma and the Body: A Sensorimotor Approach to Psychotherapy. W.W. Norton.
Van der Kolk, B. (2014). The Body Keeps the Score. Penguin.