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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    tastes of our food, the sensations of the skm or internal organs, force themselves upon attention. Such phenomena tend to confirm the crude statement, recently renewed with manifold assertions and imposing array of argument, by Dr. Miinsterberg: The will is only a complex of sen- sations. The act of will, even in its highest form, is to be explained — this authority argues — as a sensory-motor process, by the ordinary presuppositions of natural science, and without the help of any immaterial principle. But there are other phenomena which defy such easy- going attempts at solution of the mystery of body and mind. [The diminishing of discernment-time by voluntary attention has already been remarked (p. 371).] When, for example, we are attending to any sensation which is peri- odically repeated but very weak, fluctuations in its inten- sity constantly tend to occur. Thus a black radius on a white disk, when revolving, can be made to lengthen and shorten alternately. So the ticking of a watch can, by placing its distance aright, be made somewhat rhythmically to alternate between audible and inaudible. Now if atten- tion, when directed to the sensation, is left to itself, as it were, it will vacillate with a regular periodicity — the explanation of which is not quite clear, and the length of which differs for different senses and under different cir- cumstances. But voluntary and concentrated self-directed attention influences this period. By voluntary attention we can intensify a sensation, and make clearer a perception or idea, in consciousness. We incline, indeed, to attend to the stronger of two excitations of sense; but, within certain limits, we can attend where we will. We incline to attend to objects lying in the point of regard of the visual field; but we can will to attend to objects lying in the outward portion of this field. By vol- untary attention we can bring into clear consciousness the otherwise invisible double images. Some experimenters