Contrast sensitivity to radial frequencies modulated by Jn and j n Bessel profiles
Data(s) |
01/11/2002
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Resumo |
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. |
Formato |
text/html |
Identificador |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001100014 |
Idioma(s) |
en |
Publicador |
Associação Brasileira de Divulgação Científica |
Fonte |
Brazilian Journal of Medical and Biological Research v.35 n.11 2002 |
Palavras-Chave | #Spatial frequency #Angular frequency #Polar gratings #Face perception #Contrast sensitivity |
Tipo |
journal article |