Emotion, Motivation, and Anxiety: Brain Mechanisms
and Psychophysiology
Peter J. Lang, Margaret M. Bradley, and Bruce N. Cuthbert
The organization of response systems in emotion is
founded on two basic motive systems, appetitive and
defensive. The subcortical and deep cortical structures
that determine primary motivated behavior are similar
across mammalian species. Animal research has illumi-
nated these neural systems and defined their reflex out-
puts. Although motivated behavior is more complex and
varied in humans, the simpler underlying response pat-
terns persist in affective expression. These basic phenom-
ena are elucidated here in the context of affective percep-
tion. Thus, the research examines human beings watching
uniquely human stimuli—primarily picture media (but
also words and sounds) that prompt emotional arousal—
showing how the underlying motivational structure is
apparent in the organization of visceral and behavioral
responses, in the priming of simple reflexes, and in the
reentrant processing of these symbolic representations in
the sensory cortex. Implications of the work for under-
standing pathological emotional states are discussed,
emphasizing research on psychopathy and the anxiety
disorders. Biol Psychiatry 1998;44:1248–1263 © 1998
Society of Biological Psychiatry
Key Words: Emotion, anxiety, brain mechanisms, moti-
vation, fear
Introduction
The aims of this paper are twofold. First, a theoretical
model of emotion is presented that is founded on basic
experiments from both the animal and human research
laboratories. In this view, emotions are held to be products
of Darwinian evolution. Expressed emotions developed
from primitive actions that facilitated the survival of
species and individuals. In man, the evolved affects are
best characterized as motivationally tuned states of readi-
ness. The second aim of this paper is to show how this
approach generates a useful technology, facilitating par-
ticularly the study of human anxiety disorders. Applica-
tions are described that can aid