Trauma and the Developing Brain

New and emerging brain science continues to inform our understanding of trauma and its profound effects on the growing child, reaching into adulthood.

Each part of the brain has critical periods of development in utero, infancy, throughout childhood and into early adulthood. When trauma occurs during these crucial periods, neural pathways are disrupted, inhibiting development and diminishing brain function.

The following information informs how we work with children and young people and all familiy members with lived experience of trauma.

Traumatized people chronically feel unsafe inside their bodies: The past is alive in the form of gnawing interior discomfort. Their bodies are constantly bombarded by visceral warning signs, and, in an attempt to control these processes, they often become expert at ignoring their gut feelings and in numbing awareness of what is played out inside.

Dr Bessel van der Kolk, The body keeps the score: Brain, mind, and body in the healing of trauma, Penguin, New York, 2015

Three stages of brain development

This image shows the major parts of the brain as it develops from the bottom up; brain stem, limbic system and cortical brain.

The bottom-up approach of the developing brain

Brain stem

The brain stem, often referred to as the reptilian brain, is the oldest part and develops first. It controls our most basic bodily functions, such as breathing and blood circulation, as well as instinctive survival thinking and behaviour. The limbic system develops next. It includes key components such as the amygdala and the hippocampus, which are involved in behavioural and emotional reactions, such as love, anger, fear and pleasure.

Limbic system

Within the limbic system, the amygdala acts as the ‘alarm system’ of the brain. If the amygdala determines we are safe, we have access to our cortical brain and can function on a high level. If the amygdala identifies a threat, it initiates the ‘fear response’. This releases stress chemicals (e.g., cortisol and adrenaline) which activate the ‘fight, flight, freeze’ response. This can disrupt the connection to the higher level neocortex and makes thinking through or reasoning in the moment impossible. This could manifest as a child demonstrating explosive outbursts, running away, or shutting down completely and not moving. At any time, a trauma response could be triggered by events or other stimuli that are not related to their initial trauma, but are processed by the individual’s amygdala as threatening, causing confusion, frustration or discomfort.

Cortical brain

The part of our brain that deals with higher level cognitive skills is the cortical brain, or neocortex. By interacting with all other parts of the brain, the neocortex allows us to make sense of what we see, feel or hear, and assists with impulse control. Higher order brain functions such as attention, perception, language, thought, and decision- making are thus enabled. This part of the brain is not fully developed until early adulthood.

Trauma triggered responses

Health professionals may, with good intentions, ask a series of questions in order to make a diagnosis or suggest a therapeutic intervention and be met with a number of trauma triggered responses. These behaviours may be instinctive responses to a perceived threat, a trauma response. If so, at this time, the child might be unable to rationalise and make sense of what is happening around them due to this dysregulated state.

Co-regulation

Identifying that the response might be an activation of the threat/fear part of the brain allows health workers to respond to the child with empathy and understanding, which is a trauma-informed practice. For some children, co-regulation through touching, hugging or rocking may meet their emotional needs in that moment.
For others, sitting next to them calmly and holding the space may be enough. For others still, co- regulation may require just being in their line of vision as a reassuring presence.

Fight, flight or shutdown mode

A consequence of repeated exposure to trauma is that the amygdala becomes more reactive and, as a result, registers danger more frequently and with a lower threshold. This means that over time, smaller things might set off this response in a child and they may be in a state of fight, flight or shutdown more often. This makes it difficult for them to make non-emotive rational decisions and respond in ways that are seen as appropriate.

Trauma response systems

Health professionals may encounter these response systems being enacted during consultation and sessions.

Hyperarousal

A heightened state of anxiety or arousal characterised by irritable behaviour, sleep problems, exaggerated startle response and other concentration problems.

Hypervigilance

A heightened state of awareness and expectation that something bad is about to happen. The brain is locked into permanent ‘battle stations’ or alert, causing inappropriate or even aggressive reactions in everyday situations.

Freeze and shutdown

A state in which a perceived threat is completely overwhelming and too much for the fight or flight system to cope with. The brain goes into a ‘freeze’ state, a collapse response or a ‘shutdown’ disassociation response.

The upstairs and downstairs brain

Conceptualising the brain as two functional components, Dan Siegel and Tina Bryson introduced the concept of the ‘upstairs’ and ‘downstairs’ brain. The downstairs brain is more automatic and instinctive and includes the brainstem and limbic system.

The upstairs brain, the neocortex, takes time to develop, is the area where higher order thinking and reasoning develops, and allows for complex thought.

A child with developmental trauma may respond with their downstairs brain more often than a child without a history of trauma, as their threat/fear response is being triggered repeatedly, making their world a dangerous place where the fight/flight/ shutdown response is a default position. We can see these reponses throughout life.

Source: Adapted from DJ Siegel & TP Bryson, The whole-brain child: 12 revolutionary strategies to nurture your child’s developing mind, Scribe, Brunswick, Vic., 2012.