Footfalls above "we would see the tracing on the stage floor of a tremendously elongated variation of the figures 8 turned on its side … the mathematical symbol for infinity." Beckett was also indebted to the French psychologist Pierre Janet for his conception of hysterical behaviour. In his overview of Janet's work, Robert Woodworth in his "Contemporary Schools of Psychology", a work Beckett read, pays particular attention to Janet's description of the "hysterical paralysis of one arm", which Beckett incorporated, into May's posture. There are a number of analogies between "Footfalls" and Janet's work with a patient called Irène: He lists
Digit symbol substitution test Digit symbol substitution test Digit symbol substitution test (DSST) is a neuropsychological test sensitive to brain damage, dementia, age and depression. The test is not sensitive to the location of brain-damage (except for damage comprising part of the visual field). It consists of (e.g. nine) digit-symbol pairs (e.g. 1/-,2/┴ ... 7/Λ,8/X,9/=) followed by a list of digits. Under each digit the subject should write down the corresponding symbol as fast as possible. The number of correct symbols within the allowed time (e.g. 90 or 120 sec) is measured. The DSST contained in the Wechsler Adult Intelligence Scale is called 'Digit