Hormonal influences on motivation, learning, and memory processes.

Experiments have shown that the hypothalamic, pituitary, and adrenocortical hormones play an important role in the motivational value of environmental cues, in the acquisition of knowledge, and in the long-term memory of learned behavior. In human volunteers, a synthetic fraction of ACTH seems to improve visual memory, enhance alertness, and increase motivation--all without the hormone's usual endocrine effects.