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ON TIME AS AN ELEMENT IN MENTAL FUNCTIONS.
In many cases of affection of the sensorium as in the progress of recovering from apoplectic seizure, or generally in cases of partial coma a certain and often considerable time may be observed to elapse, between a question asked of the patient, and his reply. And this, seemingly without any uncertainty as to the answer to be given, or any apparent fault in the act of articulation, except slowness and greater effort; but rather as if the mind received the perception more tardily than is natural, or more slowly put itself into action through the external organs in reply. Occasionally, though aware of the fact from former experience, I have been led by the length of the interval to ask a second question before the first was answered; this answer following afterwards as if nothing had intervened.
The fact I have stated will be recognised as familiar by all who have been observant of such cases. Yet I doubt whether this element of time, in its relation to the different mental functions, both in healthy and morbid state, has been sufficiently adverted to by physiologists; fertile though the topic is in curious results, and almost forced upon us for inquiry by common language and feeling on the subject.
Is there not, in fact, a material variation in the time in which the same mental functions are performed by different individuals; depending on different organization, or on other causes of which we can give no account? And this, not
merely in complex acts of association, or continued trains of thought, (where the notion of difference is most sanctioned by phrases of common use, and can scarcely be rejected) but also in the rapidity with which perceptions are received from the senses, and volitions carried into effect on their appropriate organs—or in other words, both in acts purely mental, and in those functions by which the mind is associated with material phenomena?
If there be cause to infer this from comparison of individuals, the inference is yet more distinct and remarkable from comparison of states in the same person, and from that examination of consciousness which every one may make for himself. It will be felt that there are moments when the perceptions and thoughts are not only more vivid, but seem to pass more rapidly and urgently through the mind, than at others: and the same with respect to acts of the voluntary power.* It is possible, indeed, that these two conditions of time and intensity may have close relation together, so that one forms a sort of measure of the other; but this would carry the discussion into points too subtle and metaphysical to be dealt with here. The application of the element of time to mental phenomena, though it may seem simple at first view, from their being all actually included under it, does in truth involve much of abstruse inquiry; well fitted, however, to repay those who love the indulgence of such speculations. +
* Locke intimates something to this effect in saying, “There is a kind of restiveness in almost every one's mind. Sometimes, without perceiving the cause, it will boggle and stand still, and one cannot get it a step forward; and at another time it will press forward, and there is no holding it in."
The hypothesis which best perhaps accords with, and explains, the relation of time to the mental functions, is that which regards the mind as a series of states or feelings, succeeding to each other from the first
I would notice in connexion with this subject the question, lately raised or revived, as to the velocity of nervous action in its simplest sense; and the possible difference of rate in different persons, and even in different nerves of the same individual. An apparent sanction has been given to the reality of such differences, by the singular facts which M. Nicolai, of the Manheim Observatory, records respecting the variation of time in the observation of a simple and single astronomical fact (the transit of a star across the micrometer thread of a fixed telescope), as noted by different observers on the same spot. The inequality, however, indicated by these observations, is far too great to admit of its being supposed dependent on unequal rate of transmission by the nerves of vision and hearing :- and Müller's solution is probably correct, which supposes the perceptions from the eye and ear in this case to be distinct and successive states of mind, with varying interval between them in different individuals; a solution which accords with the views just given, and with all that we know of mental phenomena.*
Pursuing the subject into details, we find many facts to
moment of life to the last, and no two of which are strictly coincident in time. However it may seem to contradict the old notion of the vovç KUKλoç, this manner of viewing the mind has much of reality to recommend it. It obviously includes the idea of time—that is, of possible greater or less rapidity in the succession of states and illustrates more happily than any other hypothesis the numerous phenomena (making up, it may almost be said, the totality of life) in which the mind is wholly occupied with one perception or thought — or, as it might better perhaps be expressed, one subject of consciousness to the momentary exclusion of every other, even of those which come most closely in precedence or sequence to it. Every psychical theory, as well as every deduction applied practically to the purposes of life, must be brought into relation with this view, to render them justly admissible.
* See Dr. Baly's translation of Müller's Handbuch der Physiologie, p. 680.
illustrate it in the state of health; as many (and more striking from being less familiar) under morbid conditions of the body. During extreme old age, which in such various ways expresses by gradual change the sudden anticipations of disease, there appears to exist, not merely an impairment of the powers of perception and volition, but also of those functions upon which association or suggestion depend. The train of thought may be just in every sense, but it is more slowly pursued. A longer time, in the strict meaning of the phrase, is required for those combinations and changes which are involved in every such continuous action of mind. Here too, as in disease, there is more of toilsome effort in all acts of association and thought. The mind speedily becomes fatigued; the chain is broken; and confusion ensues. Observation shows these changes, occurring in every possible grade, in the cases which medical practice brings before us; and they often afford the most curious and unexpected analysis of conditions of thought, which in their more perfect and healthy state are indissolubly blended together.
It has been supposed by some that the state of dreaming involves a more rapid course of ideas through the mind; -a vague notion, however, as every thing that relates to the vos OVEIρw seems destined to be; and seemingly incapable of proof. All we can affirm here is, that the transitions are more frequent and abrupt than in the waking state, when the regulation of the will is present; and that, as respects rapidity in the succession of thoughts, it is probably as various during sleep as at other times. The evidence of such variation, while we are awake, is much more decisive. We derive it from consciousness in ourselves, and observation of the minds of others; and we are frequently able to apply a certain measure to these mental changes by their relation to things without.
One particular topic rising out of this general view has not been so much considered, as its interesting nature, and relation to all the mental functions, might have rendered likely. This is, the variation in the faculty of the mind of holding one single image, or thought, continuously before it, as the subject of contemplation. The limit to this faculty in all men is certain and obvious, and in most cases narrower than is generally supposed. The persisting retention of the same idea manifestly exhausts the mind, and the effort persevered in beyond a given time does often more entirely dissipate it. But nevertheless the power as to time is very different in different individuals; is susceptible of cultivation; and, if cultivated, with care not to produce exhaustion in the discipline, becomes a source of some of the highest excellencies of our moral and intellectual nature. It stands contrasted with that desultory and powerless state of mind which is unable to regulate its own workings, or to retain the thought fixedly on points most essential to the object of it.*
In all these instances we have the element of time entering, more or less directly, into our view of the mental functions engaged. Active disease here, as in so many other cases, by disturbing the relation of these different functions, exalting some and depressing others, affords results more strongly marked than we can obtain in the state of health; and frequent examples, involving the same notion of time, will occur to all who are sedulous in watching these changes. I have seen within the last few hours a case of typhus mitior, in which the tendency had just come on to confusion and slight delirious rambling; where, though each question I put was rightly answered in the end, it seemed as if the mind had a
* In Chapter XV., page 252., will be found some remarks which bear on this subject.