Arousal
Arousal is a basic physiological response to the presentation of stimuli. When this occurs, a non-conscious affective process takes the form of two control mechanisms; one mobilizing and the other immobilizing. Within the human brain, the amygdala regulates an instinctual reaction initiating this arousal process, either freezing the individual or accelerating mobilization.
The arousal response is illustrated in studies focused on reward systems that control food-seeking behavior (Balleine, 2005). Researchers have focused on learning processes and modulatory processes that are present while encoding and retrieving goal values. When an organism seeks food, the anticipation of reward based on environmental events becomes another influence on food seeking that is separate from the reward of food itself. Therefore, earning the reward and anticipating the reward are separate processes and both create an excitatory influence of reward-related cues. Both processes are dissociated at the level of the amygdala and are functionally integrated within larger neural systems.
Read more about this topic: Affect (psychology)