Contrast sensitivity to radial frequencies modulated by Jn and j n Bessel profiles

Brazilian Journal of Medical and Biological Research

M.l.b. Simas¹  N.a. Santos¹ 

[1] ,Universidade Federal de Pernambuco Departamento de Psicologia Laboratório de Percepção VisualRecife PE ,Brasil

关键词: Spatial frequency;    Angular frequency;    Polar gratings;    Face perception;    Contrast sensitivity;   

DOI  :  10.1590/S0100-879X2002001100014

来源: SciELO

【 摘 要 】

We measured human contrast sensitivity to radial frequencies modulated by cylindrical (Jo) and spherical (j o) Bessel profiles. We also measured responses to profiles of j o, j1, j2, j4, j8, and j16. Functions were measured three times by at least three of eight observers using a forced-choice method. The results conform to our expectations that sensitivity would be higher for cylindrical profiles. We also observed that contrast sensitivity is increased with the j n order for n greater than zero, having distinct orderly effects at the low and high frequency ends. For n = 0, 1, 2, and 4 sensitivity tended to occur around 0.8-1.0 cpd while for n = 8 and 16 it seemed to shift gradually to 0.8-3.0 cpd. We interpret these results as being consistent with the possibility that spatial frequency processing by the human visual system can be defined a priori in terms of polar coordinates and discuss its application to study face perception.

【 授权许可】

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