Citation

Freeman E. J. Exp. Psychol. 1929; 12(4): 324-340.

Copyright

(Copyright © 1929, American Psychological Association)

DOI

10.1037/h0070034

PMID

unavailable

Abstract

The writer reviews the history and previous work done upon the Aubert-Foerster phenomenon. This has to do with peripheral visual acuity when small figures and letters are seen at a short distance compared with acuity when large figures and letters are seen at a correspondingly greater distance. Aubert showed that the distance between the object and the fixation point in the case of the large figure could be much less than the strict geometrical proportionality demanded. The large figures suffer a reduction in clarity and elicit a lower degree of acuity of peripheral vision. Heinrich made the lens and its accommodation exclusively responsible. Jaensch was the first to conceive visual perception as a function involving the whole organism, demonstrating that it would not suffice to know the physical factors which govern the production of the ultimate retinal image, at any rate in the case of acuity in the periphery. Freeman finds that with the splitting method the A-F. phenomenon was eliminated and shown to be no more than a function of method. The splitting method brought out a reversal of the situation existing in the A-F. of the translation method. Here the large stimulus revealed an enormous advantage in acuity over the small. Freeman raises the question, what will happen when the splitting method is used with instantaneous illumination? By the use of a technique of his own he found that no quantitative discrepancies occurred between the two different sized constellations, and both must be allowed to have been equally well resolved. Thus he says we have a coincidence with the inference of geometrical optics that identical retinal images, regardless of size and distance of the external objects, should be resolved equally well in the same retinal spot. (PsycINFO Database Record (c) 2012 APA, all rights reserved)