Outlines of physiological psychology : A text-book of mental science for academies and colleges / by George Trumbull Ladd.

  • George Trumbull Ladd
Date:
1891 [©1890]
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of physiological psychology : A text-book of mental science for academies and colleges / by George Trumbull Ladd. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    curves. In every such small fragment the whole curve slumbers. Physiological Theories of Eeproduction. — The nature of the physical basis of memory, considered as reproductive, is even more purely conjectural than that of memory considered as retentive. The most probable conjectures, however, are those which follow along the lines already indicated. A perpetuation of persistent and similar vibra- tions in the form of weaker echoes does not seem prob- able. The term, dynamical associations, has been chosen by one writer (M. Ribot) to describe those tendencies to allied and combined action which become established in and between the different nerve-elements and cerebral centres. Another writer (Professor Wm. James) has expressed his views as to the nature of the physical basis for the laws of association as follows : The amount of activity at any given point in the brain cortex is the sum of the tendency of all other points to discharge into it, — such tendencies being proportionate (1) to the number of times the excite- ment of each other point may have coexisted with that of the point in question; (2) to the intensity of such excite- ments ; and (3) to the absence of any rival locality or process functionally disconnected with the first point, into which the discharge might be diverted. Every presen- tation, says another writer (E^'ouill^e), tends to associate with other presentations on account of the identity of their seat in the brain. . . . Contiguity in time links things only by means of a contiguity in extension of the brain. Thus are established in the nerve-paths, as on the railroads, junc- tions analogous to those where the switchman determines the course of the trains. [Is there, then, something to be said of a mental switchman determining the course of these trains of ideas ?] But these, and all similar physio- logical theories of reproduction, seem to us far too simple