On certain disorders and defects of memory / by Thomas Laycock, M.D.

  • Laycock, Thomas, 1812-1876.
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: On certain disorders and defects of memory / by Thomas Laycock, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    ness of any kind whatever, is doubtful. The notion of an organic change with retention, or the primary and most essential part of memory, has always had practical recognition; but abstract terms, such as mind and memory, have been used by metapliysicians to indicate the locxis in quo. Thus tlioughts, events, and things are often described as recorded in— written on—impressed on—stamped on—rooted in—burnt into— the memory ; the various phrases being used to indicate intensity of tlie retentive process. Nor has it been uncommon to substitute brain for abstract riotions. In the passage in which Macbeth ad- dresses the physician, and asks for relief, Shakespeare denotes four distinct theories of memory. I quote three of them : Canst thou not minister to a mind diseased? pluck from the memory a rooted sorrow? raze out the written troubles of the. brain? Any hypothesis of this kind is, however, too materialistic for use. The brain is not and cannot be written on or impressed. What happens is a cerebral vital change, which is the double result of mind or mental energy and vital energy acting conjointly with cer- tain molecular energies, under certain physical conditions of the organic basis. The whole series of processes are vital, and have their analogies in other vital processes.^ Simply, the mechanism is this : the process of retention takes place in relation, firstly, to some antecedent retention ; and, secondly, to some external impressions : the one includes recall, as association of ideas ; the other, recall in relation to external impressions, as recollection or remembrance. Thus, when a man ties a knot on his handkerchief, in connexion with a certain intention he has fixed in his mind, so that he may be re- minded of his intent by the touch of the knot, he receives virtually, w^hen so reminded, a physical impression on or through the sense of touch, which being transmitted onwards to the locus in quo in the brain, acts on the organic seat of the retention, and so the organic change coincident with remembrance is excited, and he does what he intended. This process is, in fact, one of those cerebral states which, according to my view, are dependent on the reflex action of the brain. The first stage is an example of cerebral sensory reflex action or association of ideas ; tlie second, of reflex cerebral motor action. In thought without volitional activity, the reflex action is not directly induced by external impressions, but indirectly and by successional waves of change in the sensory vesicular neurine. It is a well-established fact of experience, that all the processes included under memory and association of ideas are natural and vigorous, according as the nutrition of the brain is healthy and vigorous. The state of nutrition thus suitable to healthy mental activity depends upon various conditions, of which I may mention chiefly four :—1. A supply of healthy blood containing suitable See, for a discussion of this point, Mind and Brain, vol. ii. chap. i. 2, On the Substratum of Conscient Mind.