242 Considerations on Function [CHAP. 



my " frontal " area. Now it has been demonstrated that the " frontal " cortex possesses 

 histological characters to some extent resembling those of the " intermediate precentral " 

 cortex, and from this the question arises, is there a functional correspondence ? The solution 

 to the problem is not forthcoming. This " eye area " apparently does not exhibit any 

 specialisation of structure, and it is most difficult to say why its stimulation or destruction 

 affects ocular muscles. If the existence of a primary eye movement centre, analogous to 

 the various centres in the " precentral " area and located in the precentral neighbourhood, 

 were only proved, we might reasonably conclude that this " frontal " area represents a higher 

 centre of control and all would be plain, but that primary area is wanting. We are 

 left therefore to take our choice of two flimsy hypotheses : we must either conclude that the 

 " frontal " area contains a combined ocular centre for automatic and volitional movements, or, 

 since stimulation of the calcarine cortex produces ocular movements and this and the frontal 

 cortex are united by subcortical bands, we must assume that the ocular paralysis and the 

 movement consequent on frontal destruction and stimulation, respectively, are referred effects. 



.The head movements mentioned as occurring in these cases of frontal lesion I prefer 

 to explain by involvement of the higher centres controlling neck muscles, placed as I believe 

 in the "intermediate precentral" area in advance of the primary "precentral" area. 



To pass in review all the clinical evidence bearing on the supposed psychical faculties 

 possessed by the frontal lobe, and arising out of Meynert's oi'iginal contention that it is 

 a centre for abstract thought, would be a profitless undertaking, as from the point of view 

 of localisation a large proportion of the published cases are valueless on account of the gross 

 nature of the lesion, and because extraneous conditions cannot be excluded as causes of 

 the observed mental changes ; moreover, it has been shown by Williamson, Welt, and others, 

 who have collected and analysed series of cases, that the products of clinical medicine are 

 almost as discrepant and contradictory as those of experiment. 



I shall therefore confine myself to some brief comments on the symptoms of frontal 

 lesions to which authorities attach most importance. 



In the first place it seems agreed that a defect involving both frontal lobes, whether 

 the result of atrophy, non-development, or destructive lesion, is invariably accompanied by 

 intellectual deficiencies of a gross character, ranging from imbecility to complete idiocy. 



Secondly, it appears clear that unilateral lesions, if slight in extent, may remain latent 

 as regards the display of symptoms. 



Thirdly, although a large number of cases of extensive unilateral lesions has been 

 recorded, similarly void in effect, in a majority of instances, and especially when the lesions 

 have been left-sided, a peculiar form of mental disturbance has been observed. The disturbance 

 has been commonly described as an alteration in character. Jastrowitz, who has seen many 

 examples of the condition, names it " Witzelsucht l ," and the English equivalent seems to 

 be " moral insanity." A low sense of honour, a delight in causing annoyance, and in making 

 malicious attacks on individuals not in a position to retaliate, a tendency to be violent 

 when their childish waywardness is opposed, a lack of all feelings of gratitude, and an 

 inefficient control over their animal passions are samples of the mental changes to which 

 these subjects seem to be liable, and no better illustration of the condition is on record 

 than that afforded by the well-known case in which a crowbar entering the cranium 



1 \Vitzeln = to make a false display of wit. 



