1907.] 



0)1 Dexterity and the Bend Sinister. 



647 



jargon, and it is only when verbal utterances have a proper inter- 

 relation and convey a meaning, that speech is attained. But the 

 asphasic man although speechless is not wordless, for he understands 

 what is said to him and can therefore receive a proposition although 

 he cannot express it ; he can recognise an object although he cannot 

 name it ; he can utter interjections when alarmed or moved, and 

 when he is vexed he can swear ! 



But the receiving of a proposition is automatic ; he cannot help 

 it ; recognition does not involve the voluntary revival of words, but 

 of visual impressions, and exclamations and oaths are for the most 

 part involuntary and automatic explosive discharges. 



AVhat the common aphasic has lost is the voluntary use of words, 

 not their automatic revival, and an analysis of his condition makes it 

 clear that the left half of the brain is for the more voluntary repro- 

 duction of movements, and the right half for their more automatic 

 reproduction. Both halves are alike in so far as each contains 

 processes for words ; but they are unlike in that the left only is for 

 the use of words in voluntary speech, and the right for other processes 

 in which words serve. 



As Hughlings Jackson has again and again declared — and this 

 apphes to hand movements as well as to those of speech — the left 

 hemisphere is the more voluntary and the right the more automatic. 

 In all voluntary operations the left hemisphere leads. 



The left may be described as the more intellectual, the right as the 

 more emotional hemisphere. As in most powerful emotions there is 

 bilateral expression, it is difficult to get proof of this in movements ; 

 but I may point out that in winking, which is generally an emotional 

 expression dependent on a centre close to the thumb-centre in the 

 brain, there is a decided preferential performance on the left side. 

 Nearly 4 per cent, have lost the art of winking, o8 per cent, retain it 

 equally on both sides, but about ?)b per cent, can wink only with the 

 left eye, while 2:^ per cent, can wink only with the right. 



Winking Powee in 957 Persons : 694 Males, 263 Females. 



Males 



Females .. 

 Both Sexes 



Greater in 

 Eight Eye. 



Greater in 

 Left Eye. 



144 



Per cent. 

 = 20-74 

 80 = 30-41 

 224 = 23-45 



253 



80 



333 



Per cent. 

 = 36-25 

 r 30-41 

 = 34-79 



Equal in Both 

 Eyes. 



Per cent. 



286 = 41-21 



79 = 30-03 



365 = 38-14 



Cannot Wink. 



Per cent. 

 11 = 1-58 

 24 = 9-13 

 35 = 3-65 



The essential point to bear in mind is that the left is the leading 

 hemisphere. Goodsir, the greatest anatomist of the last century, 

 taught that the brain is composed of two symmetrical elements : 

 symmetrical apart unsymmetrical in combination screws which inter- 



