Negative congruence effects in letter and pseudo-letter recognition: the role of similarity and response conflict

Letters and pseudo-letters were presented in three experiments using a sequential same-different task. While first items were always presented in isolation, the second item was either presented in isolation or surrounded by geometrical non-target shapes that could be congruent or incongruent to the target. In two experiments, a physical sameness criterion was used. In Experiment 1, in one condition, different pairs were always distinct in shape, in another they were similar in shape. Negative congruence effects were obtained for different pairs that are similar. In Experiment 2, this effect is replicated within participants. In this experiment, similar and dissimilar stimuli were mixed. The results were explained in terms of the difficulty of responding different to stimuli that are similar in shape: when the second item is surrounded by a congruent shape, the similarity is emphasized, making this response even more difficult. In Experiment 3, the same stimuli were presented using a categorical sameness criterion. This reduces the role of physical similarity and thus eliminates the response conflict. As a result, negative congruence effects were no longer observed. Taken together, the three experiments identify another source of negative congruence effects besides the ones recently reported in the literature.     

Visual similarity effects in detecting letter rhymes

Previous demonstrations of "visual" effects in auditory tasks have been largely restricted to orthographic effects with word stimuli. As a result, explanations of such effects have centered around a shared orthography--the similarity of the spelling patterns at the ends of the words. In the present study, these effects were extended to single-letter stimuli. Subjects made rhyming decisions about pairs of letters presented auditorily. Visually similar letter pairs facilitated responses to rhyming pairs and inhibited responses to nonrhyming pairs. The results indicate that visual effects are not restricted to word stimuli and suggest that additive effects of visual similarity and shared orthography may be responsible for these findings.     

The role of letter recognition in word recognition

In a paradigm that avoids methodological problems of earlier studies, evidence was gathered addressed to the question of whether we read letter by letter. If word recognition involves letter recognition, then the difficulty of recognizing a word should vary with the difficulty of recognizing its letters. This was tested by assessing letter difficulty in two letter discrimination tasks and in a letter naming task, and then comparing 15 adult subjects' visual recognition latency to 72 easy-letter words and to 72 difficult-letter words. Word frequency and word length were also manipulated. Results indicated no effect for letter difficulty, although recognition latency reliably decreased with word frequency and monotonically increased with word length (21 msec/letter), suggesting that we do not read letter by letter, but that whatever plays a role in word recognition is smaller than the word and correlated with word length in letters.     

Some factors affecting tachistoscopic letter recognition

Summary The paper reports a series of studies that attempt to examine the issue of tachistoscopic identification of letter material. In particular a reductionist approach is used to investigate the influence of retinal locus, cerebral dominance, metacontrast, letter symmetry, and ocular dominance on the task. Retinal locus, metacontrast, and ocular dominance were shown to influence letter reportability under the present conditions with, it is argued, retinal locus and metacontrast affecting the integrity of the icon. Evidence is given for the construct of ocular dominance as the eye (dominant) initiating eye movements with the other passively following.     

The extraction of phrase structure during reading: Evidence from letter detection errors

In light of recent suggestions regarding the prominence of structure in speech production and comprehension, it has been postulated that structural processing might also play a similarly important role in reading. Some evidence in support of this contention can be gleaned from eye-movement research. However, more systematic support comes from recent work on letter detection during reading, which has shown that the rate of omission errors is inordinately high for morphemes that disclose phrase structure. The results of three lines of research suggest that, early in text processing, readers attempt to extract a structural frame for the sentence to help the on-line integration of accessed representations, and that structure-supporting units recede to the background as the meaning of the sentence evolves.     

Contrasting five different theories of letter position coding: evidence from orthographic similarity effects

Five theories of how letter position is coded are contrasted: position-specific slot-coding, Wickelcoding, open-bigram coding (discrete and continuous), and spatial coding. These theories make different predictions regarding the relative similarity of three different types of pairs of letter strings: substitution neighbors, neighbors-once-removed, and double-substitution neighbors. In Experiment 1, we used an illusory word paradigm and found that neighbor-once-removed similarity contexts resulted in fewer illusory word reports than substitution neighbors but more illusory words than double-substitution neighbors. In Experiments 2 and 3, we used a masked form priming technique with a lexical-decision task. The pattern of facilitation was as predicted by spatial coding but was incompatible with slot-coding, Wickelcoding, and both versions of open-bigram coding. These results provide further support for the SOLAR (self-organizing lexical aquisition and recognition) model of visual word identification.     

Temporal order of strokes primes letter recognition

Does the perception of objects that are the result of human actions reflect the underlying temporal structure of the actions that gave rise to them? We tested whether the temporal order of letter strokes influences letter recognition. In three experiments, participants were asked to identify letters that temporally unfolded as an additive sequence of letter strokes, either consistent or inconsistent with common writing action. Participants were significantly faster to identify letters from consistent temporal sequences, indicating that the initial part of the sequence contained sufficient information to prime letter recognition. We suggest that letter perception reflects the temporal structure of letter production; in other words, Simon sees as Simon does.     

Temporal order of strokes primes letter recognition

Does the perception of objects that are the result of human actions reflect the underlying temporal structure of the actions that gave rise to them? We tested whether the temporal order of letter strokes influences letter recognition. In three experiments, participants were asked to identify letters that temporally unfolded as an additive sequence of letter strokes, either consistent or inconsistent with common writing action. Participants were significantly faster to identify letters from consistent temporal sequences, indicating that the initial part of the sequence contained sufficient information to prime letter recognition. We suggest that letter perception reflects the temporal structure of letter production; in other words, Simon sees as Simon does.     

Factorial similarity of letter and number series comprising identical rules

Letter series and number series tests, comprising items based on identical rules, were administered in a counterbalanced design to 320 undergraduates in order to determine the similarity of factorial structure by means of Tucker’s coefficients of congruence. Results indicated that the letter and number series tests, in which each item in one had a same-rule counter-part in the other, possessed limited factorial similarity because only 4 of the 8 identically constituted factors yielded coefficients of congruence between .80 and .91 (median = .85). Examination of item-wise patterns of responses of the persons, whose total scores on the letter series tests were five or more points lower than their total scores on the corresponding number series tests, revealed certain tactics of this group (n = 92) that might account for the lack of adequate factorial similarity.     

Factorial similarity of letter and number series comprising identical rules

Letter series and number series tests, comprising items based on identical rules, were administered in a counterbalanced design to 320 undergraduates in order to determine the similarity of factorial structure by means of Tucker’s coefficients of congruence. Results indicated that the letter and number series tests, in which each item in one had a same-rule counter-part in the other, possessed limited factorial similarity because only 4 of the 8 identically constituted factors yielded coefficients of congruence between .80 and .91 (median = .85). Examination of item-wise patterns of responses of the persons, whose total scores on the letter series tests were five or more points lower than their total scores on the corresponding number series tests, revealed certain tactics of this group (n = 92) that might account for the lack of adequate factorial similarity.