R.E. Cytowic. The Neurological Side of Neuropsychology. Cambridge: MIT Press, 1996. This introductory textbook discusses key aspects of the limbic system.

A.R. Damasio, Descartes' Error: Emotion, Reason, and the Human Brain. New York: Grosset/Putnam Press, 1994. This paradigm-shifting look at the important role of emotions in tasks previously thought to be relatively unemotional is written for the layperson. It focuses on experiments with Elliot, a patient who has too little emotion to perform certain jobs well.

G. Duchenne. The Mechanism of Human Facial Expression. New York: Cambridge University Press, 1990. (Reprint of 1862 dissertation.) This wonderfully illustrated classic explores the facial expressions connected with particular emotions and how to read them; for example, how to tell a sincere smile from a false one.

D. Goleman. Emotional Intelligence. New York: Bantam Books, 1995. This book nicely summarizes the arguments for the greater importance of emotional intelligence over IQ, especially in situations involving human health and interactions.

R.S. Lazarus. Emotion and Adaptation. New York: Oxford University Press, 1991. Although this book makes no comments about computers, it is a comprehensive resource of research on emotions.

I.R. Murray and J.L. Arnott. "Toward the Simulation of Emotion in Synthetic speech: A Review of the Literature on Human Vocal Emotion." J. Acoust. Soc. Am. 93 (February 1993): 1097-1108. This paper provides a fairly up-to-date technical overview of research in modeling, recognizing, and synthesizing emotional expression in speech.

R.W. Picard. "Affective Computing." Perceptual Computing Technical Report no. 321. Cambridge: MIT Media Laboratory, 1995. This paper, and a forthcoming book from MIT Press with the same title, describe giving computers the ability to recognize, express, and possess emotions. It proposes several mechanisms for achieving this end and outlines over fifty applications for affective computers.