Visual processing of form: evidences for angular narrow-band frequency channels in humans

The aim of this work was to characterize and to compare the response curves of the human visual system for angular filters of 1 and 4 cycles/360º defined in polar coordinates. We measured 15 curves for each filter with 5 adult volunteers using a supra-threshold summation method with a forced-choice...

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Bibliographic Details
Published in:Psicologia, reflexão e crítica reflexão e crítica, 2005-01, Vol.18 (1), p.98
Main Authors: Santos, Natanael Antonio dos, Nogueira, Renata Maria Toscano Barreto Lyra, Simas, Maria Lúcia de Bustamante
Format: Article
Language:Portuguese
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Summary:The aim of this work was to characterize and to compare the response curves of the human visual system for angular filters of 1 and 4 cycles/360º defined in polar coordinates. We measured 15 curves for each filter with 5 adult volunteers using a supra-threshold summation method with a forced-choice paradigm. The results showed maximum summation effects at test frequencies for angular (1 and 4 cycles/360º) filters surrounded on both sides by strong inhibition. These results were in agreement with the existence of channels or narrow-band angular filters operating in the human visual system either through summation or inhibition of specific frequency ranges.
ISSN:0102-7972
1678-7153
DOI:10.1590/S0102-79722005000100013