T. N. Cornsweet, J. Opt. Soc. Am. 46, 987 (1956).
J. Nachmias, J. Opt. Soc. Atm. 49, 901 (1959).
J. Nachmias, J. Opt. Soc. Am. 51, 761 (1961).
K. Gaarder, Science 132, 471 (1960).
D. H. Fender, Brit. J. Ophthalmol. 39, 294 (1955).
F. Ratliff and L. A. Riggs, J. Exptl. Psychol. 40, 687 (1950).
R. W. Ditchburn and B. L. Ginsborg, J. Physiol. 119, 1 (1953).
Approximately 6% of the records were measured twice. The second measurements were made throughout the several months of film reading without access to prior data. The variance attributable to measurement error is: SF, 0.074 saccades; mean horizontal position, 0.049′; mean vertical position, 0.012′; DM, 0.087′, and logAp, 0.001 (min arc)2.
To illustrate, the standard deviation of the horizontal component of rotation might not be affected by changes in luminance while along some other meridian large effects do, in fact, occur. Since such directional nonuniformities along various meridians within and between individuals have been shown, a measure of dispersion which includes all directions of rotation was used.2,3.An alternative approach would be to find the meridian along which maximum and minimum treatment effects do occur for each subject.
W. Cochran and G. Cox, Experimental Designs (John Wiley & Sons, Inc., New York, 1957).
These effects could be of two kinds: a somewhat mysterious effect of after-images of small targets which aids in the fixation of larger ones; or practice effects, relatively stable fixation of large targets requiring periodic trials with smaller ones.
See R. M. Steinman, Ph.D. dissertation (University Microfilms, Ann Arbor, Michigan, 1964) for the complete analyses of variance and tabled data.
J. Krauskopf, T. N. Cornsweet, and L. A. Riggs, J. Opt. Soc. Am. 50, 572 (1960).
"Local sign" refers only to a signal which can be used to guide the direction and size of corrective eye movements. Such "motor local signs" may be related to other "local signs" which lead to the perceived direction or movement of an object in space relative to the observer. See J. Bruel and G. Albee, Psychol. Rev. 62, 391 (1955) for a discussion of the possible relationship of eye position and eye movements to the perception of direction and movement.
S. L. Polyak, The Retina (The University of Chicago Press, Chicago, 1941).