Recognition and the localization of visual traces.

If an unknown figure is shown in one retinal position, will this figure be recognized later when it is shown in another retinal position? This question was answered in the affirmative more than fifty years ago by J. von Kries and the experiments of Becher confirmed Von Kries' position,' but psychologists have continued to set' some effect of retinal position on recognition. Stimulation of the left half of t' retina activates the striate area of the left hemisphere and stimulation of the right side of the retina activates the right hemisphere. If a figure is first presented in such a way that its image falls on the left half of the retina and later is projected on the right half of the retina, the path of neural excitation to the cortical locus of the first process certainly is different from what it would be if the second presentation were made in the same retinal location as the first one. If memory traces are localized at the cortical place of the primary process which they represent, or if that place is in some other fashion involved in their arousal, such differences in the path of neural excitation should indeed exist. There is, of course, still the question whether such a difference, if it exists, can be detected. We know of iour at-