Page:American Journal of Psychology Volume 21.djvu/548

536 of which are sensuous, rather than perceptual, but have yet the motor significance of perceptual or sense data attended to.

3rd. A period in which the volitional part of the process consists only in the maintenance of the "set," the details which enter into it taking care of themselves, provided the "set" is not disturbed beyond a certain degree of habitual fluctuation.

The bearing of these experiments upon the general nature of voluntary movement may be summarized as follows:

(1) Where a movement involving external objects is new and highly volitional, attention is normally objective, dealing with percepts of the immediate, rather than with images of past movements.

(2) Those sensations are functionally most important which reveal the present situation most faithfully in accordance with the tendencies of the individual and the exigencies of the situation.

(3) Kinaesthetic sensations become prominent, but do not necessarily take on guidance value, when the situation is complex and stimulating.

(4) It is only when a certain degree of skill and proficiency has been reached that imagery (in contradistinction to percepts) of any sort becomes important. This imagery was uniformly derived from the preceding perceptual experiences in making the movements (voluntarily) and not from reflex and involuntary activities. In other words this imagery has a conscious source. The experiment affords no evidence for such a thing as imagery derived from purely reflex and unconscious experiences.

(5) It does, however, afford evidence that much of the control imagery as such fades away with practice and that in the last stages of a voluntary movement a complex idea of the general situation, with little or no particular imagery of a clear character, is sufficient to carry on a series of practiced movements. In this stage the sensations arising from the movements themselves to not necessarily give rise to perceptions, but perform their proper functions without the aid of supplementary ideational processes.

(6) There is some evidence that this complex idea or "set" of consciousness may in the case of such movements as those of type-writing be purely verbal so far as its image aspect is concerned, although the eye-closed writing gives evidence that concrete sensory processes facilitated the writing even at the end.