Sentence:  And so the authors conclude : `` The conduct of the patient in his every-day life and in his work , even more than the foregoing facts [ mentioned above under 1 ] , leave positively no room for doubt that the sense of touch , in the ordinary sense of the word , was unaffected ; or , to put the same thing in physiological terms , that the <WSD>performance</WSD> capacity of the tactual apparatus , from the periphery up to the tactual centers in the brain , - that is , from one end to the other - was unimpaired '' . 
Meaning of the word marked with <WSD> tags:  the act of performing; of doing something successfully; using knowledge as distinguished from merely possessing it