Visual and phonetic codes and the process of generation in letter matching.

Abstract

Physically identical letter pairs are matched more quickly than are nominally identical or nonidentical pairs, which is an effect usually interpreted as resulting from the use of a visual memory code versus a phonetic or name code. However, prior manipulations of phonetic confusion and visual-field lateralization have provided little evidence consistent with this notion. Here, three reaction time experiments suggest through converging confusion and visual-field manipulations that a phonetic code is not used in either simultaneous or successive letter matching. Two additional experiments yield confusion evidence consistent with a rapid visual generation process underlying nominally identical and nonidentical matches, emphasizing the role of visual memory processes in all of the commonly used same-different letter-matching tasks. Implications for coding and hemispheric theories are discussed.

Symmetry and similarity effects in the comparison of visual patterns

“…This finding is difficult to reconcile with Proctor's notion that all simultaneous letter matching is done according to a "name" code, as is the recently reported failure of phonetic confusion to affect both simultaneous and successive matches (Boles & Eveland, 1983). Furthermore, the symmetry effects suggest, as they did in Experiment 1, that somewhat disparate processes underlie "same" and "different" matches.…”

Case effects in letter-name matching: A partial replication

“…One possibility comes from the work of Boles and Eveland (1983). They reported converging evidence that mixed-case letter pairs are not matched using a name or phonetic code, but rather may be matched following a generation process that evokes visually represented opposit e cases of the letters .…”

A masked priming ERP study of letter processing using single letters and false fonts

“…Moreover, the P260 priming effect was distributed similarly between conditions: maximal at bilateral, medial, posterior sites, which was clearly illustrated in voltage maps of the difference waves (refer to Figure 6B). Although the results of a number of behavioral and neuroimaging studies in which cross-case (e.g., Boles & Eveland, 1983;Bowers et al, 1998;Petit et al, 2006;Shin et al, 2006) how could false fonts access that code? It is conceivable that the specialized expert processing of letters (assumed in the college student participants, who had no history of reading or language disorder and normal or corrected-tonormal vision) is designed in such a way as to allow for great variability and even inaccuracy in the way that the elements of the letters are assembled and presented.…”

“…In adults, the accuracy and latency of letter-naming responses are unaffected by changes in case in a masked priming paradigm with pairs of single letters, even when the visual features of the letters are dissimilar (Bowers et al, 1998), suggesting that letter naming is, at least in part, dependent on case-insensitive representations. In simple matching tasks, identical letters (AA) are matched more quickly than letters that are not identical orthographically but have the same name (Aa; e.g., Boles & Eveland, 1983;Posner & Boies, 1969;Posner & Keele, 1967). According to Haber and Cole (1980), "the reaction time differences between visual and name matches suggest that the visual representations are established more rapidly or take less time to process than name matches" (p. 183), consistent with at least two separable levels of letter processing: one (earlier) based on visual features and another (later) based on more abstract name information.…”