C. Blakemore and F. W. Campbell, J. Physiol. (London) 203, 237 (1969).

C. Blakemore and P. Sutton, Science 166, 245 (1969).

15 B. Bourdon, La perception visuelle de l'espace (Schleicher Frères, Paris, 1902), p. 116.

J. G. Robson and F. W. Campbell in Symposium on the Physiological Basis for Form Discrimination (Hunter Laboratory of Psychology, Brown University, Providence, R. I., 1964), p. 44.

F. W. Campbell, G. F. Cooper, J. G. Robson, and M. B. Sachs, J. Physiol. (London) 204, 120P (1969).

F. W. Campbell, G. F. Cooper, and Christina Enroth-Cugell, J. Physiol. (London) 203, 223 (1969).

F. W. Campbell, R. H. S. Carpenter, and J. Z. Levinson, J. Physiol. (London) 204, 283 (1969).

C. Blakemore and F. W. Campbell, J. Physiol. (London) 203, 237 (1969).

F. W. Campbell and D. G. Green, J. Physiol. (London) 181, 576 (1965).

F. W. Campbell and J. G. Robson, J. Physiol. (London) 197, 551 (1968).

F. W. Campbell, R. H. S. Carpenter, and J. Z. Levinson, J. Physiol. (London) 204, 283 (1969).

F. W. Campbell, G. F. Cooper, and Christina Enroth-Cugell, J. Physiol. (London) 203, 223 (1969).

F. W. Campbell, G. F. Cooper, J. G. Robson, and M. B. Sachs, J. Physiol. (London) 204, 120P (1969).

F. W. Campbell, G. F. Cooper, and Christina Enroth-Cugell, J. Physiol. (London) 203, 223 (1969).

G. Fechner, Elements of Psychophysics, Trans. H. E. Adler (H. Holt, New York, 1966), p. 176.

C. H. Graham in Vision and Visual Perception, C. H. Graham, Ed. (John Wiley & Sons, Inc., New York, 1965), Ch. 15.

F. W. Campbell and D. G. Green, J. Physiol. (London) 181, 576 (1965).

Because, in our experiments, the subject was about equally often correct on the two types of trial, the normal deviates have a particular significance in the theory of signal detectability [See D. M. Green and J. A. Swets, Signal Detection Theory and Psychophysics (John Wiley & Sons, Inc., New York, 1966).] Let us suppose that the internal effect of the frequency of a grating can be represented by a random variable. Let us further suppose that, for a given frequency, the random variable is distributed normally, with only the mean of the distribution depending upon the frequency of the grating. Upon these assumptions, the normal deviate of correct responses is just half the value of the mean difference between the distributions generated on high- and low-frequency trials in units of their standard deviation.

G. B. Henning and S. L. Grosberg, J. Acoust. Soc. Am. 44, 1386 (1968).

G. B. Henning and S. L. Grosberg, J. Acoust. Soc. Am. 44, 1386 (1968).

G. B. Henning, J. Acoust. Soc. Am. 39, 336 (1966).

F. W. Campbell, R. H. S. Carpenter, and J. Z. Levinson, J. Physiol. (London) 204, 283 (1969).

A. Pantle and R. Sekuler, Science 162, 1146 (1968).

F. W. Campbell, G. F. Cooper, J. G. Robson, and M. B. Sachs, J. Physiol. (London) 204, 120P (1969).

J. G. Robson and F. W. Campbell in Symposium on the Physiological Basis for Form Discrimination (Hunter Laboratory of Psychology, Brown University, Providence, R. I., 1964), p. 44.

F. W. Campbell and J. G. Robson, J. Physiol. (London) 197, 551 (1968).

F. W. Campbell, G. F. Cooper, J. G. Robson, and M. B. Sachs, J. Physiol. (London) 204, 120P (1969).

A. Pantle and R. Sekuler, Science 162, 1146 (1968).

C. Blakemore and P. Sutton, Science 166, 245 (1969).

Because, in our experiments, the subject was about equally often correct on the two types of trial, the normal deviates have a particular significance in the theory of signal detectability [See D. M. Green and J. A. Swets, Signal Detection Theory and Psychophysics (John Wiley & Sons, Inc., New York, 1966).] Let us suppose that the internal effect of the frequency of a grating can be represented by a random variable. Let us further suppose that, for a given frequency, the random variable is distributed normally, with only the mean of the distribution depending upon the frequency of the grating. Upon these assumptions, the normal deviate of correct responses is just half the value of the mean difference between the distributions generated on high- and low-frequency trials in units of their standard deviation.

F. W. Campbell, G. F. Cooper, and Christina Enroth-Cugell, J. Physiol. (London) 203, 223 (1969).

C. Blakemore and F. W. Campbell, J. Physiol. (London) 203, 237 (1969).

C. Blakemore and P. Sutton, Science 166, 245 (1969).

J. G. Robson and F. W. Campbell in Symposium on the Physiological Basis for Form Discrimination (Hunter Laboratory of Psychology, Brown University, Providence, R. I., 1964), p. 44.

F. W. Campbell and J. G. Robson, J. Physiol. (London) 197, 551 (1968).

C. H. Graham in Vision and Visual Perception, C. H. Graham, Ed. (John Wiley & Sons, Inc., New York, 1965), Ch. 15.

A. Pantle and R. Sekuler, Science 162, 1146 (1968).

F. W. Campbell, G. F. Cooper, J. G. Robson, and M. B. Sachs, J. Physiol. (London) 204, 120P (1969).

F. W. Campbell and D. G. Green, J. Physiol. (London) 181, 576 (1965).

F. W. Campbell, R. H. S. Carpenter, and J. Z. Levinson, J. Physiol. (London) 204, 283 (1969).

Because, in our experiments, the subject was about equally often correct on the two types of trial, the normal deviates have a particular significance in the theory of signal detectability [See D. M. Green and J. A. Swets, Signal Detection Theory and Psychophysics (John Wiley & Sons, Inc., New York, 1966).] Let us suppose that the internal effect of the frequency of a grating can be represented by a random variable. Let us further suppose that, for a given frequency, the random variable is distributed normally, with only the mean of the distribution depending upon the frequency of the grating. Upon these assumptions, the normal deviate of correct responses is just half the value of the mean difference between the distributions generated on high- and low-frequency trials in units of their standard deviation.

G. B. Henning, J. Acoust. Soc. Am. 39, 336 (1966).

G. B. Henning and S. L. Grosberg, J. Acoust. Soc. Am. 44, 1386 (1968).

G. Fechner, Elements of Psychophysics, Trans. H. E. Adler (H. Holt, New York, 1966), p. 176.

15 B. Bourdon, La perception visuelle de l'espace (Schleicher Frères, Paris, 1902), p. 116.