The simplest type of subconscious motor response consists in carrying out a more or less suitable and habitual action, while remaining unaware of its accomplishment—a lapse, accordingly, not of performance, but of notification of the accomplished service to the conscious self. A. proceeds to wind his watch at a certain stage of his undressing to find it already wound through subconscious habit; B., already retired for the night, leaves his bed to lock the door and finds it securely fastened, and doubtless by his unobservant self; C, working at his desk on a warm summer's day, decides to remove his coat and finds he has already done so; D. looks about distractedly for a particular shirt and finds it on his own person under the one he had decided to discard; E., a clergyman, sends out the contribution plate a second time, much to the consternation of the congregation; F., a railway employee, changes the position of a switch, unaware that he has already reversed it, and wrecks a train: and so on with considerable variation of scene, plot and dramatis personæ. Let me note again that these instances involve a weakened sensory apperception, inasmuch as the second action is initiated because the first performance was so feebly attended to, so distractedly appreciated. Doubtless, more frequently than the complete dropping of the link out of consciousness is the doubt, the query, whether one really has wound the clock, or locked the door, or put out the lights, or posted the letters, or taken one's medicine, or even eaten one's lunch; and one proceeds to verify by actual examination or by some definite memory-clue that it has been done.[1]
I must give at least one instance of this memory-clue and its mode of working. A student, in this case a married student, had been entrusted to attend to some domestic commissions on his way to the university. Suddenly, in seeing the word 'business' in the course of his work, it flashed across his mind that he had forgotten the commissions; yet he was not sure. In trying to recall whether he had made the purchases or not, there clearly echoed in his mind the sound of the squeak of the door in leaving the shop. This sensory impression was his surest indication, and proved to be a reliable one, that he had entered the
- ↑ The complementary memory failure occurs when one is quite certain that one of these habitual tasks has been done, and is confronted with conclusive evidence that it has not. It is the slight claim that the performance thereof has to our conscious attention that makes possible each kind of failure. It is not so much as lapses of memory, but as inattentive occupations that the instances are here apposite; and it is this aspect of them that makes proper their citation as motor lapses.
not yet sufficiently recovered to bear one's weight; after operations to one's teeth, one unintentionally disobeys the dentist's injunction not to eat on that side for a day or two. A more complex instance of a lapse of this type is that of a young man who has just had an injection of belladonna put into his eyes, and who on his way home stops to buy a paper, choses the one he wishes, and is quite unmindful of the fact that he will be unable to read it.
