CANON-BARD THEORY OF EMOTION

Canon-Bard theory

Physiologist Walter Cannon (1927) and Philip Bard (1934) theorized that the emotion and physiological arousal occur more or less at the same time. Cannon who was an expert in sympathetic arousal mechanisms, did not feel that the physical changes caused by different emotions were distinct enough to allow them to be perceived as different emotions. Bard expanded this theory by giving the idea that the sensory information that comes into brain is sent simultaneously (by the thalamus) to both the cortex (which generates emotion) and the organs of the sympathetic nervous system (which generates physiological changes in the body). The fear and the bodily reactions are, therefore, experienced at the same time and not one after the other. Cannon believed that information from the emotional stimulus goes first to the brain relay center, called the thalamus. From there the information is simultaneously relayed both to the cerebral cortex, where it produces the emotional experience, and to the hypothalamus and autonomic nervous system,  where it produces the physiological arousal that prepares one to fight , run away, or react in some other way. To Cannon-Bard, the conscious emotional experience and physiological arousal are two simultaneous and largely independent events.

Criticism

Lashley(1938) stated that the thalamus would have to be pretty sophisticated to make sense of all the possible human emotions and relay them to proper area of the cortex or the body.. It would seem that other areas of the brain must be involved in processing emotions. Emotions can be experienced without feedback from the sympathetic organs to the cortex and cited as a criticism of the James-Lange theory. People do not need feedback from those organs to experience emotion. However, there is an alternate pathway that carries information from these organs to the cortex which is the vagus nerve, one of the cranial nerves. This makes the theory a little less convincing.