Visual word recognition: Evidence for global and local control over semantic feedback.

Two lexical decision experiments examined the joint effects of stimulus quality, semantic context, and cue-target associative strength when all factors were intermixed in a block of trials. Both experiments found a three-way interaction. Semantic context and stimulus quality interacted when associative strength between cue-target pairs was strong, and the interaction was eliminated when the strength was weak. These results support a role for a local mechanism that relies on trial specific information, in addition to a mechanism that makes use of global information available across a block of trials. The absence of an interaction between the joint effects of semantic context and stimulus quality is attributed to blocking the feedback from the semantic system to the orthographic system, functionally separating the orthographic and semantic modules. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for sequential processing in visual word recognition.

The orthographic uniqueness point (OUP) of a word is introduced as the position of the 1st letter, reading from left to right, that distinguishes a word from all other printed words. In 3 experiments, observers named words that had early versus late OUPs. With unlimited viewing time, early-OUP words were named faster than late-OUP words. The effect disappeared in a delayed-naming task; hence, it was not associated with response production. The effect remained when exposure duration was reduced to limit eye movements. Results indicate that observers process the letters of a word in left-to-right order, contrary to strictly parallel accounts of word identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suedohomofoan effects in visual word recognition: Evidence for phonological processing.

Investigated the pseudohomophone effect, which is considered to be evidence that phonological recoding occurs in the lexical decision task in which a letter string like brane is identified as a nonword. 22 undergraduates read 156 letter strings, half of which were words, and identified them as words or nonwords. Half of the nonwords were pseudohomophones like brane, which sounds like a real word but is not spelled like one; half were strings like slint, which neither looks nor sounds like a real word. Response time to pseudohomophones was slower than response time to other nonwords. The interpretation of this result is that the letter string brane is transformed into a phonological code that accesses the entry for brain in a phonological lexicon, thus necessitating a time-consuming spelling check to avoid making a false positive response. Since letter strings like slint have no lexical entries, a postaccess spelling check is not necessary. Thus, the pseudohomophone effect reflects phonological processing. (French abstract) (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence of flexible coding in visual word recognition.

In 3 visual word recognition experiments, the authors examined Ss' differential dependence on phonological vs orthographic information in accessing the lexicon. The critical manipulation was the presence or absence of pseudohomophones in the nonword context of a lexical decision task. Ss received a list with either no pseudohomophones (NPsH group) or 17–30% pseudohomophones among the nonwords (PsH group). In the 1st 2 experiments Ss in the PsH group were faster and no less accurate on word trials than Ss in the NPsH group. Furthermore, performance in the NPsH group was adversely affected by phonological inconsistency in the target's orthographic neighborhood. In the final experiment, a double lexical decision paradigm was used, and performance on orthographically similar but phonologically dissimilar pairs differed in the 2 conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency effects in spoken and visual word recognition: Evidence from dual-task methodologies.

The authors report 3 dual-task experiments concerning the locus of frequency effects in word recognition. In all experiments, Task 1 entailed a simple perceptual choice and Task 2 involved lexical decision. In Experiment 1, an underadditive effect of word frequency arose for spoken words. Experiment 2 also showed underadditivity for visual lexical decision. It was concluded that word frequency exerts an influence prior to any dual-task bottleneck. A related finding in similar dual-task experiments is Task 2 response postponement at short stimulus onset asynchronies. This was explored in Experiment 3, and it was shown that response postponement was equivalent for both spoken and visual word recognition. These results imply that frequency-sensitive processes operate early and automatically. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional demands of visual word recognition.

Becker's (1976, 1979, 1980, 1985; Becker & Killion, 1977; Eisenberg & Becker, 1982) verification model was used as a framework to investigate the attentional demands of word recognition. In two experiments, a lexical decision task and an auditory probe task were performed in single- and dual-task conditions. Responses to probes were divided into detection and movement measures that indexed the demands of recognition and response output, respectively. In Experiment 1, single- to dual-task decrements in probe detection performance were larger during low-frequency as compared with high-frequency trials. This finding indicates that the attentional demands of word recognition vary with word frequency. These findings were replicated in Experiment 2, which was designed to separate a response compatibility and a capacity interpretation of the results. The findings are interpreted within Becker's verification model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strategies for visual word recognition and orthographical depth: A multilingual comparison.

We investigated the psychological reality of the concept of orthographical depth and its influence on visual word recognition by examining naming performance in Hebrew, English, and Serbo-Croatian. Experiment 1 revealed that the lexical status of the stimulus (high-frequency words, low-frequency words, and nonwords) significantly affected naming in Hebrew (the deepest of the three orthographies). This effect was only moderate in English and nonsignificant in Serbo-Croatian (the shallowest of the three orthographies). Moreover, only in Hebrew did lexical status have similar effects on naming and lexical decision performance. Experiment 2 revealed that semantic priming effects in naming were larger in Hebrew than in English and completely absent in Serbo-Croatian. Experiment 3 revealed that a large proportion of nonlexical tokens (nonwords) in the stimulus list affects naming words in Hebrew and in English, but not in Serbo-Croatian. Results support the orthographical depth hypothesis and suggest, in general, that in shallow orthographies phonology is generated directly from print, whereas in deep orthographies phonology is derived from the internal lexicon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual grouping in visual word recognition

Morphine has been reported to possess immunosuppressive actions in both in vitro as well as in vivo assays of immune function. Our work in female B6C3F1 mice, surgically implanted with a 75-mg time release morphine pellet, has confirmed previous reports of a rapid loss in the cellularity of the spleen and thymus. To evaluate the effect of morphine on the subpopulations of cells in the thymus, two color fluorescence flow cytometry studies were performed. Fluorescently conjugated monoclonal antibodies specific for the murine cell surface CD4 and CD8 markers were used to identify the four major subpopulations of thymocytes. These studies indicated that morphine pellet-implanted mice suffered a loss in each of the four thymocyte subpopulations in comparison to placebo-implanted mice. However, the loss (> 90%) in the important CD4+/CD8+ subpopulation of immature thymocytes greatly exceeded that which was observed for any other subpopulation. Kinetic studies of morphine's effect on the thymocyte subpopulations revealed that the maximal depletion of the CD4+/CD8+ cells occurs approximately 4 days after pellet implantation. Thymocyte cell populations recovered by 14 days, with an increase above placebo for the double positive cells. Naltrexone administration blocked thymic alterations, suggesting that these immunologic consequences of morphine may be mediated through an opiate receptor. Measurements in thymocytes from morphine pellet-implanted mice showed an increased level of DNA fragmentation, whereas in vitro exposure to morphine (1-100 microM) produced no such increases. This suggests morphine may be working indirectly to induce apoptosis of immature thymocytes.     

Letter legibility and visual word recognition

Word recognition performance varies systematically as a function of where the eyes fixate in the word. Performance is maximal with the eye slightly left of the center of the word and decreases drastically to both sides of this optimal viewing position. While manipulations of lexical factors have only marginal effects on this phenomenon, previous studies have pointed to a relation between the viewing position effect (VPE) and letter legibility: When letter legibility drops, the VPE becomes more exaggerated. To further investigate this phenomenon, we improved letter legibility by magnifying letter size in a way that was proportional to the distance from fixation (e.g., TABLE). Contrary to what would be expected if the VPE were due to limits of acuity, improving the legibility of letters has only a restricted influence on performance. In particular, for long words, a strong VPE remains even when letter legibility is equalized across eccentricities. The failure to neutralize the VPE is interpreted in terms of perceptual learning: Since normally, because of acuity limitations, the only information available in parafoveal vision concerns low-resolution features of letters; even when magnification provides better information, readers are unable to make use of it.     

Morphological and orthographic similarity in visual word recognition.

The differential impact of orthographic and morphological relatedness on visual word recognition was investigated in a series of priming experiments in Dutch and German. With lexical decision and naming tasks, repetition priming and contiguous priming procedures, and masked and unmasked prime presentation, a pattern of results emerged with qualitative differences between the effects of morphological and form relatedness. With lexical decision, mere orthographic similarity between primes and targets (e.g., keller–KELLE, cellar–ladle) produced negative effects, whereas morphological relatedness (e.g., kellen–KELLE, ladles–ladle) consistently resulted in facilitation. With the naming task, positive priming effects were found for morphological as well as for mere form similarity. On the basis of these results, a model of the lexicon is proposed in which information about word form is represented separately from morphological structure and in which processing at the form level is characterized in terms of activation of, and competition between, form-related entries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prosodic phonological representations early in visual word recognition.

Two experiments examined the nature of the phonological representations used during visual word recognition. We tested whether a minimality constraint (R. Frost, 1998) limits the complexity of early representations to a simple string of phonemes. Alternatively, readers might activate elaborated representations that include prosodic syllable information before lexical access. In a modified lexical decision task (Experiment 1), words were preceded by parafoveal previews that were congruent with a target's initial syllable as well as previews that contained 1 letter more or less than the initial syllable. Lexical decision times were faster in the syllable congruent conditions than in the incongruent conditions. In Experiment 2, we recorded brain electrical potentials (electroencephalograms) during single word reading in a masked priming paradigm. The event-related potential waveform elicited in the syllable congruent condition was more positive 250-350 ms posttarget compared with the waveform elicited in the syllable incongruent condition. In combination, these experiments demonstrate that readers process prosodic syllable information early in visual word recognition in English. They offer further evidence that skilled readers routinely activate elaborated, speechlike phonological representations during silent reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the locus of the word frequency effect in visual word recognition.

Examined the effect of word frequency and stimulus quality factor effects on response time (RT) performance in multi-factor lexical decision (word recognition) experiments using a sample of 54 university students. Results show that additive effects of stimulus quality and word frequency are observed in mean RTs, variances, and the ex-Gaussian parameters of the RT distribution. These findings are consistent with the conclusion that word frequency and stimulus quality affect separate stages of processing. This is consistent with the conclusion that word frequency effects reflect mapping operations between stages, but, when taken in conjunction with other reports in the literature, is inconsistent with the received view in many activation models that word frequency exerts its effect within the word detector level of representation. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Code-specific processes in word naming: Evidence supporting a dual-route model of word recognition.

This research examined visual and phonological coding in visual word recognition, Participants named words while performing 1 of 3 memory tasks. The difficulty of the memory tasks was varied. In Experiment 1, increasing the difficulty of a digit-memory load resulted in slower naming of low-frequency regular (e.g., wink) words but faster naming of low-frequency exception (e.g., pint) words. In Experiment 2, increasing the difficulty of a dot-memory load slowed naming of low-frequency exception words more than naming of low-frequency regular words. In Experiment 3, increasing the difficulty of a tone-memory load resulted in slower naming of both low-frequency regular and exception words. The results are consistent with dual-route assumptions concerning code-specific processes in word recognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Orthographic processing in visual word recognition: A multiple read-out model.

A model of orthographic processing is described that postulates read-out from different information dimensions, determined by variable response criteria set on these dimensions. Performance in a perceptual identification task is simulated as the percentage of trials on which a noisy criterion set on the dimension of single word detector activity is reached. Two additional criteria set on the dimensions of total lexical activity and time from stimulus onset are hypothesized to be operational in the lexical decision task. These additional criteria flexibly adjust to changes in stimulus material and task demands. thus accounting for strategic influences on performance in this task. The model unifies results obtained in response-limited and data-limited paradigms and helps resolve a number of inconsistencies in the experimental literature that cannot be accommodated by other current models of visual word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention constraints of semantic activation during visual word recognition.

The reduction of semantic priming following letter search of the prime suggests that semantic activation can be blocked if attention is allocated to the letter level during word processing. Is this true even for the very fast-acting component of semantic activation? To test this, the authors explored semantic priming of lexical decision at stimulus onset asynchronies (SOAs) of either 200 or 1000 ms. Following semantic prime processing, priming occurred at both SOAs. In contrast, no priming occurred at the long SOA following letter-level processing. Of greatest interest, at the short SOA there was priming following the less demanding consonant/vowel task but not following the more attention-demanding letter search task. Hence, semantic activation can occur even when attention is directed to the letter level, provided there are sufficient resources to support this activation. The authors conclude that the default setting during word recognition is for fast-acting activation of the semantic system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A phoneme effect in visual word recognition

In alphabetic writing systems like English or French, many words are composed of more letters than phonemes (e.g. BEACH is composed of five letters and three phonemes, i.e./biJ/). This is due to the presence of higher order graphemes, that is, groups of letters that map into a single phoneme (e.g. EA and CH in BEACH map into the single phonemes /i/ and /J/, respectively). The present study investigated the potential role of these subsyllabic components for the visual recognition of words in a perceptual identification task. In Experiment 1, we manipulated the number of phonemes in monosyllabic, low frequency, five-letter, English words, and found that identification times were longer for words with a small number of phonemes than for words with a large number of phonemes. In Experiment 2, this 'phoneme effect' was replicated in French for low frequency, but not for high frequency, monosyllabic words. These results suggest that subsyllabic components, also referred to as functional orthographic units, play a crucial role as elementary building blocks of visual word recognition.     

New evidence for phonological processing during visual word recognition: The case of Arabic.

Lexical decision and naming were examined with words and pseudowords in literary Arabic and with transliterations of words in a Palestinian dialect that has no written form. Although the transliterations were visually unfamiliar, they were not easily rejected in lexical decision, and they were more slowly accepted in phonologically based lexical decision. Naming transliterations of spoken words was slower than naming of literary words and pseudowords. Apparently, phonological computation is mandatory for both lexical decision and naming. A large frequency effect in both lexical decision and naming suggests that addressed phonology is an option for familiar orthographic patterns. The frequency effect on processing transliterations indicated that lexical phonology is involved with prelexical phonological computation even if addressed phonology is not possible. These data support a combination between a cascade-type process, in which partial products of the grapheme-to-phoneme translation activate phonological units in the lexicon, and an interactive model, in which the activated lexical units feed back, shaping the prelexical phonological computation process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual word recognition in bilinguals: Evidence from masked phonological priming.

Bilingual written language representation was investigated with the masked phonological priming paradigm. Pseudohomophonic and control primes of French target words were used to show that Dutch–French bilinguals exhibit the same pattern of phonological and orthographic priming as native French speakers, which suggests that the same processes underlie first- and second-language processing. It was also found that for bilinguals, but not monolinguals, it is possible to prime a target word of the second language with a homophonic stimulus (either word or nonword) of the first language. This interlingual phonological priming effect was of the same size as the intralingual priming effect. Implications for theories of bilingual written language representation and for the interpretation of the masked phonological priming paradigm are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for the use of phonological representations during transsaccadic word recognition.

The authors explored the role of phonological representations in the integration of lexical information across saccadic eye movements. Study participants executed a saccade to a preview letter string that was presented extrafoveally. In Experiment 1, the preview string was replaced by a target string during the saccade, and the participants performed a lexical decision. Targets with phonologically regular initial trigrams benefited more from a preview than did targets with irregular initial trigrams. In Experiment 2, words with regularly pronounced initial trigrams were more likely to be correctly identified from the preview alone. In Experiment 3, participants were more likely to detect a change across a saccade from regular to irregular initial trigrams than from irregular to regular trigrams. The results suggest that phonological representations are activated from an extrafoveal preview and that this phonological information can be integrated with foveal information following a saccade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Models of visual word recognition: Sampling the state of the art.

A classification of models of visual word recognition is presented that facilitates formal comparisons between models of different formats. In light of the theoretical contributions to this special section, sets of criteria for the evaluation of models and strategies for model construction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)