Acessibilidade / Reportar erro

Human visual system: psychophysical evidence for low angular frequency filters

The aim of this work was to measure narrow-band frequency response curves for four angular frequency filters whose test frequencies were 1, 2, 3 and 4 cycles/360º. Five human observers with normal or corrected visual acuity measured nine curves for each filter with a supra-threshold response summation psychophysical method allied within a forced-choice method. The results showed maximum summation effects at test frequency for filters 1, 2, 3 and 4 cycles/360º surrounded on both sides by strong inhibition. These results are consistent with the existence of narrow-band angular frequency filters operating in human visual system either through summation or inhibition of specific low angular frequency ranges.

visual perception of form; angular frequency filter; angular frequency; supra-threshold summation method


Programa de Pós-graduação em Psicologia e do Programa de Pós-graduação em Psicobiologia, Universidade Federal do Rio Grande do Norte Caixa Postal 1622, 59078-970 Natal RN Brazil, Tel.: +55 84 3342-2236(5) - Natal - RN - Brazil
E-mail: revpsi@cchla.ufrn.br