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11 WliiiiM IK OF IMIYSIOI.OOY 



neurophysiology m 



an expanding numerator representing in phylogeny 

 the growth of intellectual functions. Such a dichotomy 

 of function it was pointed out, "'provides a clue to 

 understanding the difference between what we 'feel' 

 and what we 'know'." To avoid the misleading 

 implications of the popular term rhinencephalon, the 

 limbic lobe and its associated nuclei were referred 

 to as the 'visceral brain.' In its original sixteenth 

 century meaning, 'visceral 1 pertains to strong in- 

 ward, and emotional, feelings. 



In the light of intervening developments, the ideas 

 set forth in the above paper may still serve as a 

 working hypothesis. Reference is to be made particu- 

 larly to the electrophysiological studies which have 

 shown that stimulation by was of various intero- 

 and exteroceptive systems elicit rhythmically recurring 

 potentials throughout a large part of the hippocampus. 

 In the forward part of the hippocampal gyrus, 

 gustatory and noxious stimulation evoke rhythmic 

 potentials similar to those brought about by olfactory 

 stimulation. All three of the foregoing senses accent 

 the quality and intensity of a stimulus rather than 

 its spatial relationships. It is also noteworthy that 

 emotion which is frequently experienced in con- 

 junction with discharges in this part of the brain is 

 like the aforementioned forms of sensation insofar as 

 it is registered in terms of quality and intensity. In 

 the light of the affinities of the limbic cortex generally 

 to the type that mediates the sense of smell, might 

 one infer thai it interprets experience largely in 

 terms of quality and intensity? The capacity to make 

 purely formal abstractions appears to depend on the 

 evolutionary development of the supragranular layers 

 of the neocortex where one finds a predominant 

 representation of the visual, auditory and tactile 

 senses. 



It has been suggested that the organization of the 

 frontotemporal portion of the limbic system may 

 partly account for the psychosomatic condition in 

 which emotional feelings are associated with the 

 alimentary manifestations (34, 35). As already ex- 

 plained, stimulation ot intermixed points in this part 

 of the brain elicits alimentary responses and affective 

 reactions thai one associates with the animal's search 

 lor food and struggle for survival. Patients with 

 epileptogenic loci u ithin or near this region experience 

 during the onset of their seizures emotional feelings 

 in combination with alimentary and other visceral 

 symptoms. A feeling of sadness may !»<■ followed by a 

 sense of hunger, a feeling ol fear with nausea, etc. It 



has also been suggested thai this primitive part of 



the brain may account foi the primitive psychology al 



process in which food or other edible objects are 

 treated as representatives of what is emotionally dis- 

 turbing in the environment. 



It has been pointed out elsewhere that the emotional 

 feelings of patients with psychomotor epilepsy repre- 

 sent 'raw feeling' insofar as they are not identified 

 with any particular situation or person (34, 35). In 

 other words, they represent 'feeling 1 out of context. 

 This raises the question as to how specific feelings are 

 related to specific life events. Reasons have been ad- 

 vanced for suggesting that the animalistic brain 

 formed by the limbic system accounts for confusion 

 between the internal world and the external world, 

 and makes possible the brutish stupidity whereby food 

 and other edible objects become mistaken representa- 

 tions for persons or environmental situations. If so, it 

 would seem probable that the connecting up of emo- 

 tion with reality would depend on the neocortex the 

 functions of which appear to be primarily concerned 

 with precise adaptations to the external world. Most 

 pertinent in this connection is the recognition that 

 conceptualized thought can give rise to emotion and 

 that emotion can give rise to conceptualized thought. 

 As will be pointed out in the final section, this is a 

 fundamental consideration from the standpoint of 

 psychosomatic medicine because the preservation of 

 an environmental event in the form of an idea can 

 perpetuate the emotion associated with that event and 

 thereby lead to a vicious circle. 



RECIPROCAL RELATIONSHIP OF LIMBIC I. QBE AND NEO- 

 CORTEX. Given this hypothetic.il framework, how 

 might one account physiologically for the reciprocal 

 relationship between the limbic cortex and the neo- 

 cortex? On the basis of neuronography studies there 

 appear to be no extensive 'aSSOCiational 1 connections 

 between the limbic and the neocortex. This would 

 indicate that the two depend almost entirely on ver- 

 tical, rather than horizontal, lines of communication. 

 The so-called diffuse projection svstcm of the dien- 

 cephalon offers one such possible relating system, bul 

 the evidence in this regard is still conflicting. There is 

 ample justification, however, for assuming another 

 svsiem of connections through the reticular svstcm of 

 the midbrain. This part of the brain, which has been 

 show n by Magoun and others to be essential to a slate 

 of wakefulness, has been found electrophv siulogicallv 

 to bear a reciprocal relationship to both the limbic anil 



the neocortex. In addition there is anatomical and 

 electrophysiological evidence that the central gray, 

 which lies as a core within this reticulum and which 

 plavs a dynamOgenOUS role in emotion, is related to 



