The Neuroscience of Attachment
Here we borrow extensively from an excellent article by Linda Graham written six years ago but which gives such a comprehensive review of how the neural development of our brain is affected by attachment – as it is quite long, we will be borrowing from it over three blogs.
“To understand what attachment theory and research over the last 50 years and modern neuroscience of the last 20 years are telling us:
- our earliest relationships actually build the brain structures we use for relating lifelong;
- experiences in those early relationships encode in the neural circuitry of our brains by 12-18 months of age, entirely in implicit memory outside of awareness; these patterns of attachment become the “rules”, templates, schemas, for relating that operate lifelong, the “known but not remembered” givens of our relational lives.
- when those early experiences have been less than optimal, those unconscious patterns of attachment can continue to shape the perceptions and responses of the brain to new relational experiences in old ways that get stuck, that can’t take in new experience as new information, can’t learn or adapt or grow from those experiences. What we have come to call, from outside the brain looking in, as the defensive patterns of personality disorders. What one clinician calls “tragic recursive patterns that become encased in neural cement.”
Fortunately, the human brain has always had the biologically innate capacity to grow new neurons – lifelong – and more importantly, to create new synaptic connections between neurons lifelong. All of us can create new patterns of neural firing from new experiences. All of us can pair old even maladaptive patterns with new, more adaptive, patterns of neural firing. All of us can all create new neural circuitry, pathways and networks that allow us to relate, moment by moment in new, healthier, more resilient ways. All of us can store those new more adaptive patterns in both the structures of explicit memory, making them retrievable to conscious awareness and conscious healthy functioning, and in the structures of implicit memory, making them the new habits of relating.
We begin with the brain, understanding now that the brain is a social organ, developed and changed in interactions with other brains.
There is nature; we are genetically programmed to walk, talk, learn to share, recognize an “I” separate from “you”, on a developmental timetable. That development, however, is always stimulated or kindled by experiences we have in interactions with other people, other brains. It IS interacting in relationships that stimulates brain structures to activate and mature.
On the individual level, the neurons in the limbic regions – the seat of our emotional learning that is foundational to our subjective sense of personal and social self – are not fully connected at birth. They are genetically primed to form synaptic connections through the relational experiences we have with those closest to us. Caregivers activate the growth of those regions of the brain – through emotional availability and reciprocal interactions. This includes the hormones of bonding and pleasure that are released in intimate and contingent relating. That is nurture.
…information laid down in these early moments of meeting develop the actual structure of these limbic regions. This means that the very foundations of perception, particularly in regard to relationships, relies on the quality of these earliest interactions with our parents. It is essential to understand experience dependent maturation of the brain to understand the importance of early attachment experiences to shape the brain and our patterns of relating and to embrace the power of new attachment relationships in therapy to re-wire the memories learned with this part of the brain.
…it’s not just that we have empathy because we have the pre-frontal cortex in our brains but that we have highly evolved complex brain structures like the pre-frontal cortex because they are developed and matured by empathy. As Cozolino says, we are not the survival of the fittest; we are the survival of the nurtured.
How the brain works…how relational learning works
Any experience cause neurons in our brains to fire. Repeated experiences cause neurons to fire repeatedly. Neurons that “fire together wire together,” strengthening neural connections. Strong neural connections become neural pathways and neural networks. This experience-triggered neural firing is how ALL neural pathways become patterns of response, and how all structures of the brain mature. This is how all patterns of attachment are laid down in the brain; it is also how they can change.
The brain stem regulates the internal homeostasis of the body: heart rate, respiratory rate, digestion, through the autonomic nervous system (ANS) – the extension of our brain throughout our body. The ANS has two branches, the sympathetic (SNS) of arousal and the parasympathetic (PNS) of calming. These two, arousal-calming, gas and brakes, are part of the completely unconscious social engagement system that regulates the energy level or vagal tone of our bodies. Too much SNS and too little PNS, we feel restless, agitated, stressed, all the way to panic attack.
When there is a balanced vagal tone (influence on heart rate) we are happy campers. When we feel safe in relationship our prefrontal cortex remains in charge of our physiological responding.
When we perceive threat or danger, the SNS arouses the amygdala to prepare for fight or flight. We can experience this as an emotional hijacking; our rational self temporarily nowhere to be found. When we perceive a life threat, the PNS calms down everything, down to the point of shut down.
We share these functions of the brain with all life forms down to reptiles; there’s no consciousness awareness yet; there’s no attachment going on here yet. Though, with conscious awareness later, when we say someone makes us sick to our stomach or someone is breaking our heart, it is information from the internal regulation of bodily states that unconsciously informs that subjective experience.
The most well-known structure of the limbic system is the amygdala, almond shaped structures of perception-appraisal-response. Our 24/7 alarm center, constantly scanning the environment for threat or danger, even in our sleep. The amygdala generates the fight – flight response, very important to attachment.
The amydgala is also the core of our interactive social processing and the center of our emotional learning. The amygdala assesses every experience, including relational experience, for safety or danger, for pleasure or pain, and pairs each experience with an emotional valence, an emotional charge, positive or negative, that makes us approach or avoid similar experiences in the future. The more intense the emotional charge, the more neurons will fire in our brain and the more likely we will register the experience in implicit memory.
Any such experience that is also processed with the conscious awareness of the cortex can be stored in explicit memory. We consciously learn to approach or avoid this or that person or emotion again. But the amygdala itself operates below the level of the cortex, below the radar of conscious awareness, and it stores all of its responses to experience in implicit memory, outside of awareness.
The amygdala operates much faster than the more complex cortex – 200 milliseconds to trigger fight or flight rather than the 3-5 seconds of the cortex that notices we just got in somebody’s face or bolted out of the room just precious seconds before. So the processing of the amygdala does not have to come to our awareness for an experience to register and be stored in our implicit memory.
Any emotional-relational-social experiences that are processed before the brain structures that can process experience consciously are fully mature, before 2 ½ -3 years of age, those experiences are stored only in implicit memory, only outside of awareness. This includes ALL early patterns of attachment. The research has proven “beyond irrefutability” that attachment patterns stabilize in our neural circuitry by 12-18 months of age. They are stable and unconscious before we have any conscious choice in the matter and unless new experiences change them, will remain stable “rules” of relating well into adulthood.
Cozolino suggests that because the amygdala is the structure of both our social emotional processing and is our fear center, the negotiation of relationships and the modulation of fear so overlap, our earliest relating, our earliest implicit experience of self can have a bias toward the negative. Because, evolutionarily, members of our species who were nervous, anxious, on alert, tended to survive. Those who are nice and mellow got eaten.
The hippocampus, one on each side of the temporal lobe near the ears, are part of the limbic system but as they mature, at about 2 ½ years of age, they begin translating experience into explicit memory, a vital link to cortical functioning. With explicit processing, conscious processing, we begin to remember our experiences, including relational experiences from 2 1/2 – 3 years of age on. So, the temporal lobe of the cortex is where memories of attachment experiences are stored, consciously and unconsciously; it’s where they get stuck, and when brought to consciousness, where they can change.
The hypothalamus located deeper in the limbic system releases many different hormones to regulate the amygdala. A very important one, that researchers have begun to understand more fully in the last 5-10 years, is oxytocin – the bonding hormone that is released through touch, warmth and movement, such as breastfeeding and orgasm. Oxytocin calms the amygdala, it can spur the pre-frontal cortex to grow GABA bearing fibers down to the anydgala and quell the fear response. Why hugs make us feel safe and bonded to the person who is helping to release oxytocin in our brains.
We are learning that even a visual image of someone we love or feel safe with can release oxytocin in our brains. Since imagining something is as real to our brains as seeing something for real – remembering people who have given us unconditional love, or our clients remembering us giving them unconditional positive regard, can release oxytocin and calm down the fear center.
The pre-frontal cortex can grow neuronal axons down to the amygdale; it’s only a few cell layers away. And these neuronal fibers can carry GABA (gamma butyric acid) down to the amygdala; the GABA will extinguish the fear response. (SO thinking of those we love can activate this process).
To be continued…