The double edge of neuroplasticity
Written By Sweka Sathiyaseelan
There is something so ironic about the way our brains seem to be primed with the dual capacity to harm us or to help us grow. The same mechanisms that help us to grow, learn, adapt, love and survive are also the ones which allow trauma to take hold in the brain. So, how is it that neuroplasticity - this remarkable quality that allows our brains to continually form new neural pathways, thought patterns and behaviours - also becomes the very process that lets trauma settle so deeply within?
If an experience is repeated, emotionally arduous, and tied to survival, it is very likely that the brain will remember it and rewire itself in response. It strengthens the associated neural pathways as an adaptive survival mechanism that may have been essential at the time, through a process known as neuroplasticity. Trauma doesn't simply sit in the mind like a story or a memory. It roots deep into neural circuits controlling emotion, threat processing and memory into daily behaviours, habits and reflexes, firing up in response to triggers before one realises that they are even reacting. The brain teaches itself to anticipate danger, even in safe spaces, to remain hypervigilant, locked in sympathetic fight-or-flight mode. This has very consequential impacts on a person’s daily life.
Here, the paradox appears again. 'Healing' - or at least the reduction and potential reversal of trauma - uses the same concept of 'neuroplasticity'. Through processes such as synaptic pruning and activity dependent synaptic strengthening and weakening (long-term potentiation and depression) the brain gradually weakens less repetitive circuits as new, more adaptive neural pathways are reinforced, allowing healthier patterns of thoughts, emotions and behaviours to take precedence. In the context of trauma, the brain uses such re-wiring processes to proactively replace the trauma-induced maladaptive neural pathways in our brains. This helps us to build new and healthy habits to support our wellbeing, and creates positive feedback loops to strengthen them. However neuroplasticity itself is not inherently restorative - its effects depend entirely on which neural pathways are targeted specifically. What happens when the pathways that are reinforced are related to traumatic experiences?
Trauma primarily affects the limbic system, the emotional processing centre of the brain. The amygdala usually receives information about potential danger and processes it faster than the frontal lobe can comprehend. But after emotional trauma, the prefrontal cortex is weakened, while the amygdala becomes overactive, leading to strong emotional reactions to even subtle triggers. Chronic stress elevates cortisol levels, which can deteriorate the hippocampus, by shrinking neuronal dendrites, suppressing neurogenesis, and impairing synaptic plasticity, reducing its ability to contextualise memories related to traumatic events and tipping the regulatory balance between top-down control by the prefrontal cortex and the bottom-up emotional reactivity of the amygdala. Decreased activity in Broca's area (responsible for speech) and hyperactivity in the right hemisphere, where sensory memory is stored, can result in the person having a vivid and visceral recollection of their trauma as a set of images, emotions, sound and sensation, rather than coherent verbal narratives. This pattern is most commonly observed in individuals with PTSD or acute stress disorder but can appear in patients with an imbalance in their memory processing. The same neuroplastic mechanisms apply to physical trauma. Whether it is a fracture, an injury to the central nervous system, recovery from surgical intervention or chronic illness, they all drive neuroplastic changes. Some adaptations are beneficial, such as motor area reorganisation to help someone regain the ability to walk; others are more harmful, such as when pain pathways that strengthen to the extent that the brain repeatedly fires signals even after physical healing is complete, resulting in chronic pain.
In trauma, both emotional and physical, the brain is trying to protect us by adapting- unfortunately to our detriments in the long term, long after the danger is over. But this is where the duality of neuroplasticity returns: neural pathways developed in response to trauma can be reshaped in safety.
Therapy is a significant factor in altering these brain pathways. Cognitive behavioural therapy (CBT) strengthens the connections between the prefrontal cortex and amygdala, reversing their imbalance and adverse effects, helping people regulate their emotional and rational responses more effectively. Similarly, eye movement desensitization and reprocessing (EMDR) can reduce the emotional intensity of traumatic memories by selectively altering the way they are processed and reconsolidated. It employs bilateral stimulation - typically rhythmic eye movements, which have been associated with increased delta band activity across limbic and prefrontal regions including the amygdala, hippocampus, and anterior cingulate cortex. Neurophysiological evidence suggests that EMDR decreases the affective aspects of memories in the amygdala whilst preserving their cognitive aspects in the hippocampus, which are then integrated via the anterior cingulate cortex and re-encoded in higher cortical association areas. Consequently memories become less emotionally charged, allowing a clearer distinction between past and present experiences and breaking their tight coupling with fear responses. These treatments can also be complemented by mindfulness, breathing exercises and meditation, which can improve attention, emotional regulation and help reduce hyperactivity of the amygdala, allowing the parasympathetic nervous system’s calming effects to be more effective.
With consistent practice of these resiliency skills and use of other meaningful, prosocial behaviours, such as volunteer work and community groups, one can reinforce positive thought and behavioural patterns to counteract the maladaptive wiring by favouring healthier neural networks that are not linked to experiences of trauma. Even simple repeated experiences of safety or providing oneself with growth opportunities - whether it's visiting a new country, learning a new language or fostering healthy relationships - can further support and enhance this process.
The same principle also applies to physical recovery, where repeated movement drives experience-dependent plasticity. By engaging in specific repetitive exercise to form new neuronal connections or to strengthen those that are pre-existing, one can retrain their motor maps. Another method is through motor imagery (visualisation), which activates the same networks in the motor cortex as when doing the imagined movement. In the case of recovering from strokes or spinal cord injuries, the brain can adapt by a process called cortical reorganisation; in essence, recruiting neighbouring undamaged regions to take over altered or damaged function.
The degree of neuroplasticity does vary from individual to individual; those with severe trauma and PTSD often require additional medical treatment. Nevertheless, methods that exploit the mechanisms of neuroplasticity can help in recovery greatly. Comparing recovery from both emotional and physical trauma, the similarity is evident: repetition with the right intention, can lead to the neuroplastic changes associated with improvement and progress, if not 'healing'.
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