Letter and word identification in the fovea and parafovea

Abstract

We investigated the extent to which accuracy in word identification in foveal and parafoveal vision is determined by variations in the visibility of the component letters of words. To do so we measured word identification accuracy in displays of three three-letter words, one on fixation and the others to the left and right of the central word. We also measured accuracy in identifying the component letters of these words when presented at the same location in a context of three three-letter nonword sequences. In the word identification block, accuracy was highest for central targets and significantly greater for words to the right compared with words to the left. In the letter identification block, we found an extended W-shaped function across all nine letters, with greatest accuracy for the three central letters and for the first and last letter in the complete sequence. Further analyses revealed significant correlations between average letter identification per nonword position and word identification at the corresponding position. We conclude that letters are processed in parallel across a sequence of three three-letter words, hence enabling parallel word identification when letter identification accuracy is high enough.

Lexical processing across the visual field

“…Both the accuracy and latency data demonstrated a strong right visual field (RVF) advantage indicating that words presented to the right were identified more accurately and rapidly than words presented to the left of fixation. This finding is consistent with well-documented evidence of a visual field asymmetry in studies of bilateral letter and word processing (e.g., Bouma, 1973;Ducrot & Grainger, 2007;Hellige, 1976Hellige, , 1993Jordan et al, 2003;Scaltritti et al, 2021). The RVF advantage for letter and word stimuli has been argued to reflect the lateralization of language areas in the left cerebral hemisphere (see Josse & Tzourio-Mazoyer, 2004, for a review).…”

“…It is known that visual acuity and visual crowding affect the speed and accuracy of letter and word processing outside foveal vision (Bouma, 1973;Lee et al, 2003;Legge et al, 2001;Mishkin & Forgays, 1952;. Furthermore, letters and words are processed more efficiently in the RVF than in the LVF (Ducrot & Grainger, 2007;Hellige, 1976Hellige, , 1993Jordan et al, 2003;Scaltritti et al, 2021). However, methodological differences between studies and the influence of task demands obscure precise estimates of the impact of eccentricity on word identification across the visual field.…”

“…This effect, known as spatial interference or visual crowding, is more detrimental to accurate letter and word identification than is the effect of visual acuity (Latham & Whitaker, 1996). Visual crowding is also more pronounced from spatially adjacent exterior than interior letters and words, resulting in the paradoxical finding that the final letter of a word to the right of fixation can be more clearly perceived than its initial letter, even though the former is farther from the center of vision than the latter (Bouma, 1973;Legge et al, 2001;Scaltritti et al, 2021). Other factors that modulate the influence of eccentricity on word identification have been demonstrated most clearly in experiments that have investigated the spatial limits on processing letters and words outside of foveal vision (for a discussion of these issues, see Grainger et al, 2016).…”

Lexical processing across the visual field.

“…Both the accuracy and latency data demonstrated a strong right visual field ( RVF ) advantage indicating that words presented to the right were identified more accurately and rapidly than words presented to the left of fixation. This finding is consistent with well-documented evidence of a visual field asymmetry in studies of bilateral letter and word processing (e.g., Bouma, 1973; Ducrot & Grainger, 2007; Hellige, 1976, 1993; Jordan et al, 2003; Scaltritti et al, 2021). The RVF advantage for letter and word stimuli has been argued to reflect the lateralization of language areas in the left cerebral hemisphere (see Josse & Tzourio-Mazoyer, 2004, for a review).…”

“…This effect, known as spatial interference or visual crowding , is more detrimental to accurate letter and word identification than is the effect of visual acuity (Latham & Whitaker, 1996). Visual crowding is also more pronounced from spatially adjacent exterior than interior letters and words, resulting in the paradoxical finding that the final letter of a word to the right of fixation can be more clearly perceived than its initial letter, even though the former is farther from the center of vision than the latter (Bouma, 1973; Legge et al, 2001; Scaltritti et al, 2021). Other factors that modulate the influence of eccentricity on word identification have been demonstrated most clearly in experiments that have investigated the spatial limits on processing letters and words outside of foveal vision (for a discussion of these issues, see Grainger et al, 2016).…”