strobic

For the ratio 1: 3 between the two rates, the strobic system has four bands of each color; for 1: 2, three bands of each color; while when the two rates are equal, there are two bands of each color, forming a diameter.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

On the other hand, if there were a central anæsthesia during eye-movement, the continuous process in the retina could not produce a continuous sensation, and if the interval were long enough the image might well be referred to two objects; since also, in the strobic appearances, the stimulations must succeed at a certain minimal rate in order to produce the illusion of continuous existence and movement.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

Here, too, the cycle of strobic movements is different.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

He thus compares the appearance of several rods to the appearance of several dots in intermittent illumination of the strobic wheel.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

The farther the ratio between the rates of rod and disc departs from exactly 1: 5, whether less or greater, the more rapid will the strobic movement, backward or forward, be; until finally the divergence is too great, the newly forming bands lie too far ahead or behind those already formed to fuse with them and so be apperceived as one system, and so the bands are lost in confusion.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

This disc should in any case be geared for high speeds and should be turned by hand for the sake of variations in rate, and consequently in the strobic movement.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

When produced in this way, the strobic illusion is exceedingly pretty.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

The apparatus is actually a cinematograph, but one which gives so many pictures in the second that they entirely fuse and the strobic movement has no trace of discontinuity.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

Such an interpretation is all the more to be expected, since, as the strobic phenomena show, even discontinuous retinal processes tend to be interpreted as continuously existing objects.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

It is clear that if, instead of using as 'rod' a single radial sector, one were to rotate two or more such sectors disposed at equal angular intervals about the axis, one would have the same strobic phenomena, although they would be more complicated.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889