Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters
Autor(a) principal: | |
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Data de Publicação: | 2002 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Brazilian Journal of Medical and Biological Research |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200014 |
Resumo: | We measured human frequency response functions for seven angular frequency filters whose test frequencies were centered at 1, 2, 3, 4, 8, 16 or 24 cycles/360º using a supra-threshold summation method. The seven functions of 17 experimental conditions each were measured nine times for five observers. For the arbitrarily selected filter phases, the maximum summation effect occurred at test frequency for filters at 1, 2, 3, 4 and 8 cycles/360º. For both 16 and 24 cycles/360º test frequencies, maximum summation occurred at the lower harmonics. These results allow us to conclude that there are narrow-band angular frequency filters operating somehow in the human visual system either through summation or inhibition of specific frequency ranges. Furthermore, as a general result, it appears that addition of higher angular frequencies to lower ones disturbs low angular frequency perception (i.e., 1, 2, 3 and 4 cycles/360º), whereas addition of lower harmonics to higher ones seems to improve detection of high angular frequency harmonics (i.e., 8, 16 and 24 cycles/360º). Finally, we discuss the possible involvement of coupled radial and angular frequency filters in face perception using an example where narrow-band low angular frequency filters could have a major role. |
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Brazilian Journal of Medical and Biological Research |
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Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filtersSpatial frequencyAngular frequencyNarrow-band frequency filtersPolar gratingsRadial frequencyWe measured human frequency response functions for seven angular frequency filters whose test frequencies were centered at 1, 2, 3, 4, 8, 16 or 24 cycles/360º using a supra-threshold summation method. The seven functions of 17 experimental conditions each were measured nine times for five observers. For the arbitrarily selected filter phases, the maximum summation effect occurred at test frequency for filters at 1, 2, 3, 4 and 8 cycles/360º. For both 16 and 24 cycles/360º test frequencies, maximum summation occurred at the lower harmonics. These results allow us to conclude that there are narrow-band angular frequency filters operating somehow in the human visual system either through summation or inhibition of specific frequency ranges. Furthermore, as a general result, it appears that addition of higher angular frequencies to lower ones disturbs low angular frequency perception (i.e., 1, 2, 3 and 4 cycles/360º), whereas addition of lower harmonics to higher ones seems to improve detection of high angular frequency harmonics (i.e., 8, 16 and 24 cycles/360º). Finally, we discuss the possible involvement of coupled radial and angular frequency filters in face perception using an example where narrow-band low angular frequency filters could have a major role.Associação Brasileira de Divulgação Científica2002-02-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200014Brazilian Journal of Medical and Biological Research v.35 n.2 2002reponame:Brazilian Journal of Medical and Biological Researchinstname:Associação Brasileira de Divulgação Científica (ABDC)instacron:ABDC10.1590/S0100-879X2002000200014info:eu-repo/semantics/openAccessSimas,M.L.B.Santos,N.A.eng2002-02-08T00:00:00Zoai:scielo:S0100-879X2002000200014Revistahttps://www.bjournal.org/https://old.scielo.br/oai/scielo-oai.phpbjournal@terra.com.br||bjournal@terra.com.br1414-431X0100-879Xopendoar:2002-02-08T00:00Brazilian Journal of Medical and Biological Research - Associação Brasileira de Divulgação Científica (ABDC)false |
dc.title.none.fl_str_mv |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
title |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
spellingShingle |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters Simas,M.L.B. Spatial frequency Angular frequency Narrow-band frequency filters Polar gratings Radial frequency |
title_short |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
title_full |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
title_fullStr |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
title_full_unstemmed |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
title_sort |
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters |
author |
Simas,M.L.B. |
author_facet |
Simas,M.L.B. Santos,N.A. |
author_role |
author |
author2 |
Santos,N.A. |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Simas,M.L.B. Santos,N.A. |
dc.subject.por.fl_str_mv |
Spatial frequency Angular frequency Narrow-band frequency filters Polar gratings Radial frequency |
topic |
Spatial frequency Angular frequency Narrow-band frequency filters Polar gratings Radial frequency |
description |
We measured human frequency response functions for seven angular frequency filters whose test frequencies were centered at 1, 2, 3, 4, 8, 16 or 24 cycles/360º using a supra-threshold summation method. The seven functions of 17 experimental conditions each were measured nine times for five observers. For the arbitrarily selected filter phases, the maximum summation effect occurred at test frequency for filters at 1, 2, 3, 4 and 8 cycles/360º. For both 16 and 24 cycles/360º test frequencies, maximum summation occurred at the lower harmonics. These results allow us to conclude that there are narrow-band angular frequency filters operating somehow in the human visual system either through summation or inhibition of specific frequency ranges. Furthermore, as a general result, it appears that addition of higher angular frequencies to lower ones disturbs low angular frequency perception (i.e., 1, 2, 3 and 4 cycles/360º), whereas addition of lower harmonics to higher ones seems to improve detection of high angular frequency harmonics (i.e., 8, 16 and 24 cycles/360º). Finally, we discuss the possible involvement of coupled radial and angular frequency filters in face perception using an example where narrow-band low angular frequency filters could have a major role. |
publishDate |
2002 |
dc.date.none.fl_str_mv |
2002-02-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200014 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002000200014 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0100-879X2002000200014 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica |
publisher.none.fl_str_mv |
Associação Brasileira de Divulgação Científica |
dc.source.none.fl_str_mv |
Brazilian Journal of Medical and Biological Research v.35 n.2 2002 reponame:Brazilian Journal of Medical and Biological Research instname:Associação Brasileira de Divulgação Científica (ABDC) instacron:ABDC |
instname_str |
Associação Brasileira de Divulgação Científica (ABDC) |
instacron_str |
ABDC |
institution |
ABDC |
reponame_str |
Brazilian Journal of Medical and Biological Research |
collection |
Brazilian Journal of Medical and Biological Research |
repository.name.fl_str_mv |
Brazilian Journal of Medical and Biological Research - Associação Brasileira de Divulgação Científica (ABDC) |
repository.mail.fl_str_mv |
bjournal@terra.com.br||bjournal@terra.com.br |
_version_ |
1754302931628195840 |