Cargando…

Seeing the Meaning: Top–Down Effects on Letter Identification

Most models of reading agree that visual word recognition is underpinned by a highly interactive network in which both bottom–up and top–down processes contribute. What remains unknown is whether evidence of top–down effects upon letter processing are restricted to word-form level information, or wh...

Descripción completa

Detalles Bibliográficos
Autores principales: Evans, Gemma A. L., Lambon Ralph, Matthew A., Woollams, Anna M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5397417/
https://www.ncbi.nlm.nih.gov/pubmed/28473778
http://dx.doi.org/10.3389/fpsyg.2017.00322
_version_ 1783230243213934592
author Evans, Gemma A. L.
Lambon Ralph, Matthew A.
Woollams, Anna M.
author_facet Evans, Gemma A. L.
Lambon Ralph, Matthew A.
Woollams, Anna M.
author_sort Evans, Gemma A. L.
collection PubMed
description Most models of reading agree that visual word recognition is underpinned by a highly interactive network in which both bottom–up and top–down processes contribute. What remains unknown is whether evidence of top–down effects upon letter processing are restricted to word-form level information, or whether meaning-level information also plays a role. Here we sought to investigate top–down semantic influences upon letter detection using semantic manipulations of real word imageability and semantic priming, as well as a manipulation of nonword orthographic and phonological composition which varied degree of similarity to real words. A continuous adaptive staircase procedure was used, allowing us to assess the exposure duration needed for accurate letter perception in different stimulus types. Results revealed that in terms of both exposure duration and decision reaction times, words showed an advantage over pseudohomophones and pseudowords, which in turn showed advantages over consonant strings. High imageability words were processed more efficiently than low imageability words, both in terms of the exposure duration required for accurate letter identification and also decision reaction times. The presence of a related as opposed to unrelated semantic prime significantly shortened exposure duration, but also lengthened decision reaction times. This inhibitory semantic priming effect in reaction time was attributed to the interference at the decision stage by stronger activation of the prime letters in the case of related relative to unrelated trials. Taken together, the present results establish for the first time that the semantic dimensions of imageability and semantic priming exert significant effects on letter identification, indicating meaning-level influences on the very earliest stages of written word recognition.
format Online
Article
Text
id pubmed-5397417
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-53974172017-05-04 Seeing the Meaning: Top–Down Effects on Letter Identification Evans, Gemma A. L. Lambon Ralph, Matthew A. Woollams, Anna M. Front Psychol Psychology Most models of reading agree that visual word recognition is underpinned by a highly interactive network in which both bottom–up and top–down processes contribute. What remains unknown is whether evidence of top–down effects upon letter processing are restricted to word-form level information, or whether meaning-level information also plays a role. Here we sought to investigate top–down semantic influences upon letter detection using semantic manipulations of real word imageability and semantic priming, as well as a manipulation of nonword orthographic and phonological composition which varied degree of similarity to real words. A continuous adaptive staircase procedure was used, allowing us to assess the exposure duration needed for accurate letter perception in different stimulus types. Results revealed that in terms of both exposure duration and decision reaction times, words showed an advantage over pseudohomophones and pseudowords, which in turn showed advantages over consonant strings. High imageability words were processed more efficiently than low imageability words, both in terms of the exposure duration required for accurate letter identification and also decision reaction times. The presence of a related as opposed to unrelated semantic prime significantly shortened exposure duration, but also lengthened decision reaction times. This inhibitory semantic priming effect in reaction time was attributed to the interference at the decision stage by stronger activation of the prime letters in the case of related relative to unrelated trials. Taken together, the present results establish for the first time that the semantic dimensions of imageability and semantic priming exert significant effects on letter identification, indicating meaning-level influences on the very earliest stages of written word recognition. Frontiers Media S.A. 2017-04-20 /pmc/articles/PMC5397417/ /pubmed/28473778 http://dx.doi.org/10.3389/fpsyg.2017.00322 Text en Copyright © 2017 Evans, Lambon Ralph and Woollams. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Psychology
Evans, Gemma A. L.
Lambon Ralph, Matthew A.
Woollams, Anna M.
Seeing the Meaning: Top–Down Effects on Letter Identification
title Seeing the Meaning: Top–Down Effects on Letter Identification
title_full Seeing the Meaning: Top–Down Effects on Letter Identification
title_fullStr Seeing the Meaning: Top–Down Effects on Letter Identification
title_full_unstemmed Seeing the Meaning: Top–Down Effects on Letter Identification
title_short Seeing the Meaning: Top–Down Effects on Letter Identification
title_sort seeing the meaning: top–down effects on letter identification
topic Psychology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5397417/
https://www.ncbi.nlm.nih.gov/pubmed/28473778
http://dx.doi.org/10.3389/fpsyg.2017.00322
work_keys_str_mv AT evansgemmaal seeingthemeaningtopdowneffectsonletteridentification
AT lambonralphmatthewa seeingthemeaningtopdowneffectsonletteridentification
AT woollamsannam seeingthemeaningtopdowneffectsonletteridentification