Sistema visual humano: evidência psicofísica para filtros de freqüência angular baixa

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.