N170 ERPs could represent a logographic processing strategy in visual word recognition

Gregory Simon, Laurent Petit, Christian Bernard, Mohamed Rebaï
Behav Brain Funct. 2007-01-01; 3(1): 21
DOI: 10.1186/1744-9081-3-21

Lire sur PubMed

1. Behav Brain Funct. 2007 Apr 23;3:21.

N170 ERPs could represent a logographic processing strategy in visual word

Simon G(1), Petit L, Bernard C, Rebaï M.

Author information:
(1)Groupe d’Imagerie Neurofonctionnelle, UMR 6194, CNRS CEA, Universities of Caen
& Paris Descartes, GIP Cyceron, boulevard Henri Becquerel, 14074 Caen Cedex,

BACKGROUND: Occipito-temporal N170 component represents the first step where
face, object and word processing are discriminated along the ventral stream of
the brain. N170 leftward asymmetry observed during reading has been often
associated to prelexical orthographic visual word form activation. However, some
studies reported a lexical frequency effect for this component particularly
during word repetition that appears in contradiction with this prelexical
orthographic step. Here, we tested the hypothesis that under word repetition
condition, discrimination between words would be operated on visual rather than
orthographic basis. In this case, N170 activity may correspond to a logographic
processing where a word is processed as a whole.
METHODS: To test such an assumption, frequent words, infrequent words and
pseudowords were presented to the subjects that had to complete a visual lexical
decision task. Different repetition conditions were defined 1–weak repetition,
2–massive repetition and 3–massive repetition with font alternation. This last
condition was designed to change visual word shape during repetition and
therefore to interfere with a possible visual strategy during word recognition.
RESULTS: Behavioral data showed an important frequency effect for the weak
repetition condition, a lower but significant frequency effect for massive
repetition, and no frequency effect for the changing font repetition. Moreover
alternating font repetitions slowed subject’s responses in comparison to « simple »
massive repetition.ERPs results evidenced larger N170 amplitude in the left
hemisphere for frequent than both infrequent words and pseudowords during massive
repetition. Moreover, when words were repeated with different fonts this N170
effect was not present, suggesting a visual locus for such a N170 frequency
CONCLUSION: N170 represents an important step in visual word recognition,
consisting probably in a prelexical orthographic processing. But during the
reading of very frequent words or after a massive repetition of a word, it could
represent a more holistic process where words are processed as a global visual

DOI: 10.1186/1744-9081-3-21
PMCID: PMC1884163
PMID: 17451598

Auteurs Bordeaux Neurocampus