Prolegomena to a theory of the emotions.

Abstract

PROLEGOMENA TO A THEORY OF THE EMOTIONS E. GELLHORN, M.D. Ph.D.* Sieh', so ist Natur ein Buch lebendig, Universtanden, doch nicht unverstaendlich. (So it is that nature is a living book, not understood but not beyond understanding.) GOETHE I. Current Theories Before we comment on some important aspects of the theories of the emotions, we will review briefly the main points ofthose theories which still form the basis ofour thoughts in this area. A. THB JAMES-LANGB THEORY TheJames-Lange theory held that emotional feeling really was the perception ofchanges in the activity ofviscera and skeletal muscles. In other words, emotion was the result rather than the cause ofvisceral and muscle response. Sherrington (i) objected to this theory in 1906. His objections were based on the observation of "emotional behavior" in animals deprived ofa large part ofthe sensory input from body structures. Since that time considerable additional evidence, based chiefly on Cannon's work, has accrued which makes the theory appear untenable. Hebb disagrees with those who purport to refute theJames-Lange theory on the basis ofexperiments which prevent the central nervous system from receiving signals from responding organs. Hebb (2) states that "such an argument is totally irrelevant;James did not say that emotional behavior depends on sensations from the limbs and viscera." To agree with Hebb, one must deny that behavioral signs ofemotion are valid indicators ofemotional feeling. However , they are the only signs we have that any animal or person (except * Professor Emeritus ofNeurophysiology, University of Minnesota. Aided by grant M-38-61 from the National Institutes ofHealth. This paper is part of a book on Emotions and Emotional Disorders by E. Gellhorn and G. N. Loofbourrow, to be published in 1962 by Paul B. Hoeber, Inc., New York. 403 one's self) experiences emotion, and common sense dictates that we accept them as valid indicators. B.THE CANNON-BARD THALAMIC THEORY One ofthe foremost theories to emerge as an alternative to that ofJames and Lange was the Cannon-Bard theory. According to this theory (3, 4) a "thalamic process" was essential to the experiences ofemotion. As originally postulated by Cannon, a simple relay ofimpulses to the cortex via the thalamus resulted in awareness ofthe stimulus object but no emotion. However, ifthe arrival ofimpulses at the cortex resulted in thalamic release from cortical inhibition, the released "thalamic process" added to the perception the "peculiar quality of emotion." It was also held that the "thalamic process" could be aroused directly by afferent impulses reaching it from the receptors. Unlike theJames-Lange theory, the motor responses ofemotion were thought to arise as the result ofthe emotional "thalamic process" rather than being the cause of the emotionalfeeling. Bard (5) insisted that the "thalamic process" was, of itself, inadequate. It must send signals back to the cortex to confer the emotional quality on the perception . The complete Cannon-Bard theory, therefore, considers perception with emotional coloring to depend on direct projections from thalamus to cortex plus activation of a thalamic process which secondarily affects the cortex in such a way as to give rise to emotional experience. In view ofthe facts that Cannon and Bard showed emotional behavior to be virtually abolished by destruction of the posterior hypothalamus, and that Hess (6) demonstrated various types ofemotional behavior with stimulation ofthe hypothalamus in the unanesthetized cat, it is the hypothalamus and not the thalamus which forms the core of the modern version of the Cannon-Bard theory. C.LINDSLEY's ACTIVATION THEORY OF EMOTION Lindsley's (7) "activation theory" of emotion retains the basic framework ofthe Cannon-Bard but expands it to include the reticular activating system. The theory relates not only to emotional but also to cortical arousal, sleep-wakefulness, and certain types of abnormal behavior. It is based on the following experimental evidence: (1) The electroencephalogram shows an "activation pattern" in emotion. (2) Cortical activation can be evoked by stimulation ofthe brain stem reticular formation. (3) De404 E. Gellhorn · Theory ofEmotions Perspectives in Biology and Medicine · Summer 1961 struction ofthe rostral end ofthe reticular system abolishes cortical activation and leads to apathy, somnolence, etc. (4) The reticular activating system which can arouse the cortex "is either identical with...