Dr. Lisa Feldman Barrett: Why brains predict before sensing

Under the hood, the brain constantly uses past experiences to predict what to do next (movements, physiological changes) and what you’ll feel and perceive. You don’t simply sense the world and react; you predict actions, then sensory input helps correct those predictions. This means emotions like anxiety, anger, or calm are not automatic reactions but constructed interpretations of bodily states in context—leaving room to shape them by changing context, habits, and meaning.

High arousal (fast heart rate, tension, agitation) is usually labeled as anxiety, but physiologically it can also be read as determination or readiness. Experiments show that training people to reinterpret test anxiety as determination—through repeated practice—allows them to perform better, finish courses, and change their life trajectory. The bodily state doesn’t change; the meaning and consequent actions do.

An adverse event becomes traumatic when current sensations are linked, via prediction, to past painful memories and given a particular personal meaning. One girl in a culture where physical violence by men was normalized showed no trauma until she watched Oprah, recognized her own circumstances in the stories, and adopted that traumatic meaning—after which she developed classic trauma symptoms. This illustrates that cultural narratives and models strongly shape whether an event is experienced as trauma.

You can try to reinterpret your past (psychotherapy, deep conversations), but that’s hard and not always effective. Another route is to invest in new experiences now—exposing yourself to new people, ideas, and practiced emotional skills. Repeatedly acting differently in the present (e.g., using a cup as a vase, not just for drinking; approaching bees in controlled ways if you fear them) provides ‘prediction error’ that forces the brain to update its future predictions and identity-in-action.

The brain’s primary job is regulating the body’s energy (allostasis) by running a ‘body budget’ of resources like glucose, oxygen, and electrolytes. Chronic stress, inflammation, poor sleep, social uncertainty, and hormonal factors (e.g., some birth control pills) can overload this budget, contributing to depression-like states: fatigue, poor concentration, low motivation, altered cortisol, and systemic inflammation. Interventions like better sleep, exercise, nutrition, social support, and reducing stressors can shift the underlying budget and thus mood.