A few months ago, I wrote Toward A Predictive Theory Of Depression, which used the predictive coding model of brain function to speculate about mood disorders and emotions. Emotions might be a tendency toward unusually high (or low) precision of predictions:

Imagine the world's most successful entrepreneur. Every company they found becomes a multibillion-dollar success. Every stock they pick shoots up and never stops. Heck, even their personal life is like this. Every vacation they take ends out picture-perfect and creates memories that last a lifetime; every date they go on leads to passionate soul-burning love that never ends badly.