How Emotions Are Made: The Secret Life of the Brain

by Lisa Feldman Barrett

Consider what this means: events in the world, such as a snake slithering at your feet, merely tune your predictions, roughly the way that your breathing is tuned by exercise. Right now, as you read these words and understand what they mean, each word barely perturbs your massive intrinsic activity, like a small stone skipping on a rolling ocean wave. In brain-imaging experiments, when we show photographs to test subjects or ask them to perform tasks, only a small portion of the signal we measure is due to the photos and tasks; most of the signal represents intrinsic activity. You might think that your perceptions of the world are driven by events in the world, but really, they are anchored in your predictions, which are then tested against those little skipping stones of incoming sensory input.14