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The main concepts of the Cannon–Bard theory are that emotional expression results from the function of hypothalamic structures, and emotional feeling results from stimulations of the dorsal thalamus. The physiological changes and subjective feeling of an emotion in response to a stimulus are separate and independent; arousal does not have to occur before the emotion. Thus, the thalamic region is attributed a major role in this theory of emotion. ==Origins== Walter Bradford Cannon (1871–1945) was a physiologist at Harvard University, who is perhaps best known for his classic treatise on homeostasis. Philip Bard (1898–1977) was a doctoral student of Cannon's, and together they developed a model of emotion called the Cannon-Bard Theory.〔〔(【引用サイトリンク】title=Philip Bard )〕 Cannon was an experimenter who relied on studies of animal physiology. Through these studies, Cannon and Bard highlighted the role of the brain in generating physiological responses and feelings; a role that is important in their explanation of emotion experience and production.〔 A dominant theory of emotion of Cannon's time was the James-Lange theory of emotion, and Cannon recognized that to test this theory, an examination of emotional expression with no visceral afferent feedback was required. This was necessary because the link between visceral changes and the feedback required to stimulate cerebral manifestations of an emotion would no longer be present. To do so, Cannon experimented with severing afferent nerves of the sympathetic branch of the autonomic nervous system in cats. Cannon compiled his experimental results in 1915, then refined and expanded them, and finally proposed his model of emotion as a challenge and alternative to the James-Lange theory of emotion.〔 The James-Lange theory relies on the backflow of impulses from the periphery to account for unique emotional experiences; impulses that William James assumed to come from all parts of the organism, including the muscles, skin, and the viscera. The viscera were attributed a major role by James. The viscera are composed of smooth muscle and glands. Cannon identified and outlined five issues with the James-Lange theory's notion of the vasomotor center as the explanation of emotional experience. # Total separation of the viscera from the central nervous system does not alter emotional behaviour. #:In an experiment, cats were kept alive and healthy after having their sympathetic nervous systems completely removed. Removal of this system resulted in the abolishment of all the reactions under control of the vasomotor center, the region that the James-Lange theory purported to be responsible for emotional experiences. However, it was found that destroying these functions had little or no effect on the animals' emotional responses. The cats displayed the typical signs of rage in response to a barking dog, and the animals displayed full emotional expression in all organs that had not had their connections to the brain destroyed.〔〔 # The same visceral changes occur in very different emotional states and in non-emotional states. #:The sympathetic nervous system functions as a single unit. Visceral changes brought on/caused by sympathetic nervous system action include: increased heart rate; contraction of arterioles; dilatation of bronchioles; increased levels of blood sugar; sweating; widening of the pupils and erection of hairs; and discharge of adrenin. These physiological changes can be seen in great excitement under any circumstances, including in distinguishable emotional states such as fear and rage, as well as situations of fever, asphyxia, and exposure to cold temperatures. Cannon articulated that these responses of the viscera are too uniform to offer a means of distinguishing emotions that have varying subjective qualities. He postulated that if emotions were the result of impulses from the viscera, we could expect fear, rage, chilliness, asphyxia, and fever to feel similarly, which is not the case. #The viscera are relatively insensitive structures. #:Cannon wrote that there is a common belief that the more deeply the body is penetrated, the more sensitive it becomes; however, this is not the case. In the nerves distributed to the viscera the afferent sensory fibers may be only 1/10th as numerous as the efferent sensory fibers. For example, in the case of the viscera, we are unaware of the contractions and relaxations of the digestive processes. Such processes are undemonstrative and beyond our physical awareness, even when marked changes are induced in them.〔 # Visceral changes are too slow to be a source of emotional feeling. #:As previously stated, the viscera are composed of smooth muscle and glands, which are typically sluggish in their responses. It has been found that the latent period of the psychogalvanic response in man is approximately 3 seconds. However, it has also been noted that the latent period of affective responses to photos of men and women can end within 0.8 seconds. The James-Lange theory contends that such affective responses result from reverberations from the viscera. Cannon pointed out that the time required for nerve impulses to travel from the brain to the periphery and back to the brain again could not occur quickly enough to be the cause of such emotional responses. # Artificial induction of the visceral changes typical of strong emotions does not produce them. #:When adrenalin is injected it induces the physiological responses typical of sympathetic nervous system activity previously discussed (dilation of bronchioles, constriction of blood vessels, increased blood sugar etc.). These changes are typical of intense emotional states. Therefore, if these visceral changes were artificially induced by the injection of adrenalin, one would expect the emotions to follow, as articulated by the James-Lange theory of emotion. When this experiment was done, participants experienced no specific emotions. However, it was found that an emotional response may develop only when the adrenalin as injected subsequent to discussing with patients their sick children or their dead parents. Thus, injection of adrenalin had an effect when an emotional mood already existed in participants.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cannon–Bard theory」の詳細全文を読む スポンサード リンク
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