Emotions are organized around 2 basic motivational systems, appetitive and defensive, that evolved from primitive neural circuits in the mammalian brain. The appetitive system is keyed for approach behavior, founded on the preservative, sexual, and nurturant reflexes that underlie pleasant affects; the defense system is keyed for withdrawal, founded on protective and escape reflexes that underlie unpleasant affects. Both systems control attentional processing: Distal engagement by motive-relevant cues prompts immobility and orienting. With greater cue proximity (e.g., predator or prey imminence), neural motor centers supercede, determining overt defensive or consummatory action. In humans, these systems determine affective expression, evaluation behavior, and physiological responses that can be related to specific functional changes in the brain. This theoretical approach is illustrated with psychophysiological and brain imagery studies in which human subjects respond to emotional picture stimuli.
Charles H. Hillman, Bruce N. Cuthbert, Margaret M. Bradley and Peter J. Lang
Psychophysiological responses of two rival sport fan groups were assessed within the context of Lang’s biphasic theory of emotion. Twenty-four participants, placed in two groups based on their identification with local sport teams, viewed 6 pictures from 6 categories: team-relevant pleasant sport, team-irrelevant sport, team-relevant unpleasant sport, erotica, household objects, and mutilation. Fans rated appetitive sport pictures higher in pleasure and arousal compared to aversive sport pictures. Physiological measures (startle probe-P3, the startle eye-blink reflex, slow cortical potentials to picture onset, and skin conductance) differentiated both appetitive and aversive team-relevant categories from team-irrelevant pictures, and increased orbicularis oculi EMG was found only for team-relevant appetitive pictures. These results suggest there are differences between rival sport fans in response to the same pictorial stimuli, and further suggest that fans provide an ideal population in which to measure motivation toward appetitive stimuli.