How Emotions Are Processed In the Brain

The nervous system detects safety and threat before thought.

How Emotions Are Processed in the Brain

Trauma affects not only how memories are stored, but also how emotions are experienced and interpreted. For individuals with PTSD, emotional and physical symptoms often arise automatically, shaped by underlying neurobiological changes that occurred under conditions of threat.

Understanding how emotions are processed in the brain can help explain why trauma reactions feel immediate, bodily, and difficult to control.

Neurodevelopment and Brain Change After Trauma

Advances in brain imaging have allowed researchers to observe how profound and sustained trauma physically alters the brain. These discoveries revealed the remarkable plasticity of the nervous system—how experience shapes neural structure and function.

Today, brain development is understood as use-dependent (Kain & Terrell, 2018). Repeated exposure to danger, stress, or abuse strengthens certain neural pathways while limiting others.

Research by Martin Teicher and colleagues has shown that chronic childhood trauma is associated with measurable changes in brain development. Under sustained threat, the brain becomes more emotionally reactive and less able to regulate those reactions through higher cortical processes

Bottom-Up Processing: Emotion Before Thought

The brain processes information from the bottom up. Sensory input is first evaluated by subcortical, emotional systems before reaching areas responsible for conscious thought and reasoning.

At the center of this process is the amygdala, a small structure whose primary role is survival. The amygdala continuously scans incoming sensory information—sights, sounds, smells, and internal sensations—and rapidly assigns an emotional meaning: safe, unsafe, or threatening.

This evaluation happens in milliseconds and occurs below conscious awareness. Only after this emotional assessment does information reach the neocortex, where reflection and interpretation occur.

Because of this sequence, we often feel something before we can think about it.

The Amygdala and Trauma

Under conditions of chronic threat, research suggests that the amygdala may become hyper-reactive, while communication between emotional brain regions and the neocortex is reduced.

In traumatized individuals, the amygdala may be more easily triggered by sensory cues that resemble past danger. At the same time, the neocortex—which normally helps inhibit emotional responses—may be less effective at modulating these reactions.

This imbalance helps explain why trauma responses can feel sudden, intense, and disproportionate to the present situation. Emotional reactions are activated automatically, often before conscious awareness has time to intervene.

This phenomenon is sometimes referred to as emotional hijacking—when survival circuits override reflective thought in the service of protection.

Practices that support present-moment awareness may help interrupt automatic emotional reactions.

• Mindfulness practices that support nervous system regulation

Perception, Sensation, and Trauma Triggers

We perceive the world through our sensory systems: vision, hearing, smell, touch, taste, and bodily awareness. Sensory information is routed through the thalamus and evaluated first by emotional brain systems.

If a current perception resembles a past threat—even subtly—the amygdala may initiate a full-body survival response. This can include heightened alertness, muscle tension, changes in breathing, or urges to flee or shut down.

Because these processes occur below conscious awareness, individuals may not immediately understand why they are reacting. The body responds first; understanding follows later.

Bringing the Biology Together

Trauma alters the neuroplatform of emotion—the biological foundation from which emotional and physical responses arise. Changes in emotional reactivity, threat detection, and regulation are not signs of weakness or dysfunction. They are the result of a nervous system shaped by experience.

The important question is not whether trauma changes the brain—it does—but whether those changes can be modified over time.

Research and clinical experience suggest that they can.

Through repeated experiences of safety, regulation, and connection, the nervous system can gradually reorganize. Healing does not mean erasing the past; it means helping the brain and body learn that the danger has passed.

Further Reading (Optional)

For readers who wish to explore these ideas in greater depth, the work of Bessel van der Kolk, MD has been foundational in understanding how trauma affects both brain and body. His book The Body Keeps the Score synthesizes decades of research on traumatic memory, emotional processing, and evidence-based approaches to healing.

For additional trauma-informed resources, visit the PTSD hub.

This article reflects an integrative mental health approach that considers both brain and body.

Bibliography

Dana, D. (2018). The polyvagal theory in therapy. New York: W.W. Norton & Conpany.

Kain, K. and Terrell (2018). Nurturing resilience. Berkeley, California: North Atlantic Books

Hannaford, C. (1995), Smart Moves: Why learning is not all in your head. Salt Lake City, Utah: Great River Books

Teicher, M. H., Andersen,S. L., Polcari, A. Anderson,C. M., Navalta, C. P., and Kim, D. M. (2003). The neurobiological consequences of early stress and childhood maltreatment, Neuroscience & Biobehavioral Reviews, 27 (1–2), pp. 33-44 https://doi.org/10.1016/S0149-7634(03)00007-1.

Van Der Kolk, B. (2014). The body keeps the score. Penguin Books: New York.