Emotion and its disorders.

Emotional processes are crucial to the control of human behaviour and anchored to a common foundation in motivational mechanisms where emotional cues have intrinsic re-inforcement values. Emotions per se are transient events, produced in response to external or self-generated emotive stimuli, and typically characterized by attention to the stimulus, involuntary arousal reactions and changes in motor behaviour, subjective feeling states and subsequent biasing of behaviour. Primary emotions, such as happiness and fear, correspond motivationally with approach or withdrawal responses. In humans, feeling-states and subjective emotional experiences reflect cognitive contextual awareness of emotional responses and may be embellished into secondary emotions, such as guilt or relief. This review addresses the application of neuroimaging techniques to understanding the neural mechanisms supporting these aspects of emotional experience.