Motivated behavior

Behavior which is driven through internal states or external events and that is aimed at achieving a particular outcome is motivated or goal-directed behavior.

Some motivated behavior occurs in order to satisfy physiological needs. Chemical and neural signals give rise to an internal state, hunger. This drives appetitive or target-seeking behavior which is foraging for food and subsequently consummatory behavior eating. Goal-directed behaviors like this are homeostatic and normally self-limiting as the internal state is switched off (sated) by consumption.Much motivated behavior is not so straightforward because it occurs in the absence of any obvious physiological deficit. The sexual behavior leading to copulation, while not homeostatic is driven through an internal state libido which can be sated. Still, parenting behavior is neither self-limiting nor homeostatic and little is understood about the internal state that motivates it, although hormones (e.g., oxytocin) seem to be important. What motivates several activities that are exploring a forest path, listening to music, engaging in a sport or academic study is presently a mystery.

Any stimulus which raised the probability of a motivated response occurring is a positive reinforcer. An animal will work to obtain access to a positive reinforcer. Through contrast a reinforcer is said to be negative if the animal works to avoid the stimulus in that case it is displaying aversive behavior. The reinforcing excellence of a stimulus depends on context. For instance, food is a powerful reward to a hungry person but its positive reinforcing quality diminishes with satiety. Although, a particular food may however be a positive reinforcer if it is enough delicious and novel even if the person is not hungry. Thus the motivation to eat is a complex interplay of external cues, internal state, and memory. Same qualifications apply to other goal-directed behaviors.