Advances in bioelectronics, imaging and signal processing procedures, and laboratory computing over the past several decades have rapidly increased our ability to record signals noninvasively from the brain and various peripheral physiological systems with greater sensitivity and fidelity than ever before. Nevertheless, advances in physiological signal acquisition have not yet had a consistent impact on theory and research in the social and behavioral sciences for at least three reasons: (a) insufficient technical considerations, (b) elementary signal representation or analysis, and (c) fallacious reasoning based on physiological data. To illustrate, previous research has revealed that variations in emotion are followed by distinct but sometimes visually imperceptible patterns of facial expression. These important observations have led to inferences about the physiological mechanisms underlying emotion, and to psychophysiological assessments within the behavioral and social sciences for the purpose of gauging the presence or extent of a particular psychological event or process (e.g., anxiety, emotion, group cohesion). However, except in instances in which the psychophysiological relationship is isomorphic or in which two (or more) theories make competing predictions about the physiological response, knowledge of the effects of variations in psychological/behavioral variables on a physiological response does not provide sufficient information for a strong inference about the psychological variable given this physiological response. To illustrate, research showing that a negative emotion leads to a particular pattern of visceral or facial electromyographic activity does not imply that this pattern of bodily response indexes (e.g., was preceded or accompanied by) this negative emotion. This is because knowledge that a statement is true does not imply logically that the converse is true. The current research will examine the social, psychological, and physiological processes involved in emotion using paradigms designed to avoid these problems. This research, therefore, should both establish a new paradigm or psychophysiological inquiry on important social and behavioral processes and yield more appropriate tests of existing theories of emotion.//
