Left-to-right processing of alphabetic material is independent of retinal location

Abstract

The effects of retinal location, serial letter position, and order of approximation to English on the accuracy of report of tachistoscopically presented letter arrays were examined. Processing time was controlled by a visual mask. The results show the following: (1) Overall accuracy is higher for arrays which appeared symmetrically around a central fixation point than for arrays which appeared either in the right or left visual field. (2) The first and last letters of an array are identified with the greatest accuracy except with symmetrical arrays.

How the brain encodes the order of letters in a printed word: The SERIOL model and selective literature review

“…We believe that this mechanism can account for conflicting f indings regarding the perceptibility of strings' final letters. In general, the final letter has been found to be preferentially perceived with respect to the internal letters, denoted a final-letter advantage (Hammond & Green, 1982;Lefton et al, 1978;Mason, 1982;Perea, 1998). However, in other studies the final letter was the least well perceived of all the letters (Hellige et al, 1995; error data analysis in Humphreys et al, 1990; five-and six-letter words in Montant et al, 1998).…”

“…Although, for normal subjects, letter perceptibility falls off from left to right (with the exception of the final position) for strings presented entirely within a single visual field (Lefton et al, 1978), this monotonicity is not maintained if the string is presented centrally. In that case, a W-shaped pattern of perceptibility emerges, with increased perceptibility for the letter under fixation (in addition to the initial and final letters; see Hammond & Green, 1982;Lefton et al, 1978;Mason, 1982).…”

“…Studies have shown a robust pattern of decreasing letter perceptibility with increasing string position (with the possible exceptions of the fixated letter and the final letter; see Hammond & Green, 1982;Lefton et al, 1978;Mason, 1982;Wolford & Hollingsworth, 1974). This overall pattern is generally independent of fixation point.…”

“…Experimentally, it has been noted that the pattern of perception of letters within a string violates the pattern of the acuity gradient. Numerous studies of briefly presented letter strings have shown that the initial letter of a string is the most accurately perceived of all the letters, even when the initial letter is far from fixation (Hammond & Green, 1982;Lefton et al, 1978; Mason, 1982;Wolford & Hollingsworth, 1974). This pattern cannot be attributed to decreased lateral inhibition for boundary letters; when strings of nonletter symbols are centrally presented, the initial and final symbols are the least well perceived, as would be expected if perception were simply a function of visual acuity (Hammond & Green, 1982;Mason, 1982).…”

“…Such experiments have shown that, for briefly presented letter strings, the first letter has the highest probability of being correctly recognized, the second letter has the second highest probability, with the probability of recognition generally decreasing from left to right (with the possible exceptions of the final letter and the letter at fixation; see Estes, Allmeyer, & Reder 1976;Lefton, Fisher, & Kuhn, 1978;Montant, Nazir, & Poncet, 1998;Wolford & Hollingsworth, 1974). Initial interpretations of these results postulated a serial scanning process across an input trace (Lefton et al, 1978;Mewhort, Merikle, & Bryden, 1969). More recently, interpretations have focused instead on weights derived from perceptual factors and/or position of maximal information within a string (Brysbaert, Vitu, & Schroyens, 1996;Montant et al, 1998;O'Regan, Levy-Schoen, Pynte, & Brugaillere, 1984).…”