Semantic category effects in visual word search

The initial question was whether subjects could categorize a word semantically before they precisely identified the word itself. This failed to occur. When searching a visual display for a single target word, subjects searched at the same rate whether the distractors were in the same or in a different semantic category. However, when the size of the target set was increased to three, then six, items, subjects increasingly used category information to speed their search rate when targets and distractors belonged to different categories. Subjects appeared to perform the task by comparing the category of each display word to the category of the target set.     

Semantic context and word frequency effects in visual word recognition

Semantic context and word frequency factors exert a strong influence on the time that it takes subjects to recognize words. Some of the explanations that have been offered for the effects of the two factors suggest that context and frequency should interact, and other explanations imply additivity. In a recent study, Schuberth and Eimas reported that context and frequency effects added to determine their subjects' reaction times in a lexical decision (word vs. nonword) task. The present experiment reexamines this question with improved procedures. The data show that context and frequency do interact, with a semantic context facilitating the processing of low-frequency words more than high-frequency words.     

Semantic context effects in visual word recognition: An analysis of semantic strategies

Using a procedure that isolates the facilitatory and interfering effects of a semantic context, the present study examines two distinct patterns of context effects. One pattern shows a dominance of facilitation for target words in a related context, and the other pattern shows a dominance of interference for target words in an unrelated context. The controlling factor seems to be the overall characteristics of the stimulus list. For materials that include semantic relationships that are consistent in the strength of the relationships, facilitation dominance obtains. For materials that include a wide range of semantic relationship strengths, interference dominance results. These two patterns of facilitation and interference are attributed to two semantic strategies available to subjects for using context information. The explication of the strategies includes a theoretical treatment of the present data.     

Semantic expectancy effects on word access

Summary Access to word-representations in memory was studied in an experiment that used a lexical decision task: Ss had to decide whether a string of letters was a word or a nonword. Independent variables were context-similarity and semantic expectancy. The former is defined in terms of the categorical relationship that holds between a set of context words and the subsequently presented test word. The second refers to the cue-value given to subjects as to the likelihood with which related or unrelated test words would be presented. Cue-values did not provide information on the likelihood with which word or nonword decisions were required, but only on the most probable semantic relationship holding among context and test words. In theory, Meyer and Ellis' (1970) race model for word access was extended for the present purpose. It is shown that the two search processes assumed to mediate lexical access interfere on the basis of limited processing capacity, at least under the special conditions prevailing during the experiment. Furthermore, it is shown that Ss effectively manage to control the point in time at which they decide to issue a nonword response. Cuing for related test words tends to produce faster nonword decisions than cuing for unrelated words.This paper reports work that was conceived and begun at Stanford University, Calif., USA, where the author spent a year as a post-doctoral fellow. This fellowship was made possible by the Deutsche Forschungsgemeinschaft, Bad Godesberg, Federal Republic of Germany, Grant Schm 350/1. I am grateful to R.C. Atkinson, S. Monsell, P. Matthews, and D. Vorberg for supporting this research in a number of ways.     

Semantic context effects and priming in word association

Two experiments investigated priming in word association, an implicit memory task. In the study phase of Experiment 1, semantically ambiguous target words were presented in sentences that biased their interpretation. The appropriate interpretation of the target was either congruent or incongruent with the cue presented in a subsequent word association task. Priming (i.e., a higher proportion of target responses relative to a nonstudied baseline) was obtained for the congruent condition, but not for the incongruent condition. In Experiment 2, study sentences emphasized particular meaning aspects of nonambiguous targets. The word association task showed a higher proportion of target responses for targets studied in the more congruent sentence context than for targets studied in the less congruent sentence context. These results indicate that priming in word association depends largely on the storage of information relating the cue and target.     

Semantic access in number word translation: the role of crosslingual lexical similarity

The revised hierarchical model of bilingualism (e.g., Kroll & Stewart, 1994) assumes that second language (L2) words primarily access semantics through their first language (L1) translation equivalents. Consequently, backward translation from L2 to L1 should not imply semantic access but occurs through lexical wordform associations. However, recent research with Dutch-French bilinguals showed that both backward and forward translation of number words yields a semantic number magnitude effect (Duyck & Brysbaert, 2004), providing evidence for strong form-to-meaning mappings of L2 number words. In two number-word translation experiments with Dutch-English-German trilinguals, the present study investigated whether semantic access in L1-L2 and L1-L3 number-word translation depends on lexical similarity of the languages involved. We found that backward translation from these more similar language pairs to L1 still yields a semantic magnitude effect, whereas forward translation does not, in contrast with the Dutch-French results of Duyck and Brysbaert (2004). We argue against a dual route model of word translation and suggest that the degree of semantic activation in translation depends on lexical form overlap between translation equivalents.     

Homophone interference effects in visual word recognition

In three lexical decision experiments and one progressive demasking experiment, performance on low-frequency heterographic homophones having a high-frequency mate was compared with performance on non-homophone target words with or without high-frequency orthographic neighbours. Robust homophone interference effects were observed in all experiments, as well as inhibitory effects of neighbourhood frequency. When speed-accuracy trade-offs were reduced, the homophone interference effects were found to be additive with effects of high-frequency orthographic neighbours. Furthermore, the size of homophone interference effects increased when pseudohomophone stimuli were presented among the nonwords. These results are tentatively interpreted within the framework of a bi-modal interactive activation model.     

Semantic priming effects on picture and word processing

The effects of semantic priming on picture and word processing were assessed under conditions in which subjects were required simply to identify stimuli (label pictures or read words) as rapidly as possible. Stimuli were presented in pairs (a prime followed by a target), with half of the pairs containing members of the same semantic category and half containing unrelated concepts. Semantic relatedness was found to facilitate the identification of both pictures (Experiment 1) and words (Experiment 2), and obtained interactions of semantic relatedness and stimulus quality in both experiments suggested that semantic priming affects the initial encoding of both types of stimuli. In Experiment 3, subjects received pairs of pictures, pairs of words, and mixed pairs composed of a picture and a word or of a word and a picture. Significant priming effects were obtained on mixed as well as unmixed pairs, supporting the assumption that pictures and words access semantic information from a common semantic store. Of primary interest was the significantly greater priming obtained in picture-picture pairs than in word-word or mixed pairs. This suggests that, in addition to priming that is mediated by the semantic system, priming may occur in picture-picture pairs that results from the overlap in visual features common to the pictorial representations of objects from the same semantic category.     

Semantic processing in visual word recognition: activation blocking and domain specificity

Lexical decision to a target is typically facilitated when a related prime is simply read, but is typically eliminated if subjects carry out a letter search on the prime when probe and prime appear simultaneously. Three experiments involving the addition of a task-irrelevant word to this prime search paradigm address (1) Stolz and Besner’s (1996, 1998) account in which semantic priming is eliminated because letter search on the prime instantiates an activation block between lexical and semantic levels of representation, (2) Chiappe, Smith, and Besner’s (1996) account that activation blocking is domain specific, and (3) Neely and Kahan’s (2001) claim that semantic activation is context independent and capacity free. The results are (1) consistent with the account that activation blocking is general to a level, rather than item specific, (2) consistent with the account that activation blocking is domain specific, and (3) inconsistentwith the claim that semantic activation is context independent and capacity free.     

Semantic and phonological influences on visual word learning in a transparent language

Orthographic representations of words are indispensable for reading fluency. The ways in which these representations are developed and their resistance to decay are hotly debated topics. The aim of this study was to investigate the influence of semantic and phonological representations on the formation of orthographic representations in a transparent orthography. In order to achieve this objective, an experiment with three conditions was carried out. In the first condition, a group of university students were asked to repeatedly read 10 new words after semantic and phonological training, in the second condition another group of participants read the new words after phonological training, and in the third condition participants read without previous training. Finally, a follow-up session was performed to test the resistance to decay of the orthographic representations. The results showed that participants who had received semantic training formed the representations faster than participants in the other conditions, as indicated by the decrease in length effect. These results indicate the important role of previous knowledge when people face new written words. A month later these orthographic representations still remained in the lexicon of the participants.     

Semantic cueing effects on word retrieval in aphasic patients with lexical retrieval deficit

We examined lexical access in word production, focusing on lexical retrieval deficit in aphasic patients. These patients were asked to name one picture at a time and we investigated how semantic cueing affected their ability to retrieve the word. When the subjects experienced a retrieval failure, they were presented with one type of cue, and then they tried to name the target picture again. Four types of cues were used: phonological, semantic related, semantic category member, and baseline cue. Both phonological and semantically related cues improved performance. In contrast, category member cues had no effects on releasing the retrieval block. These results can be explained by an interactive activation model in word production (Dell & O'Seaghdha, 1991).     

Semantic priming in visual word recognition: Activation blocking and domains of processing

The fact that letter search on a prime eliminates the typically robust semantic priming effect in lexical decision is often attributed to the “shallowness” of the prime-processing task. In three experiments we investigated this claim by using two different “shallow” prime-processing tasks: letter search and color identification. Consistent with previous reports, lexical decisions to semantically related targets were not facilitated when subjects searched the prime for a probe letter. In contrast, semantic priming was observed following a color discrimination task on the prime. We suggest that a levels-of-processing interpretation is not an adequate framework for understanding these data. Instead, a domain-specific processing account is offered in which explicit processing at the letter level (as in letter search) makes demands on resources (e.g., activation) that drives processing at the semantic level. This competition is resolved by establishing a temporary activation block at the lexical-semantic interface, which results in the elimination or attenuation of semantic priming. In contrast, global judgment of color is viewed as a domain that does not make demands on the resources that drive the visual word recognition machinery. There is therefore no need for an activation block, and semantic priming is not prevented.     

Familiarity effects and word unitization in visual comparison tasks

The decision that two words are identical is made more quickly than the decision that two non-words are identical. This familiarity effect was shown to be larger in a simultaneous matching task than in a sequential matching task. In the simultaneous task, two words were not matched as quickly as a single letter and a letter in a predesignated location within a word. The latter finding rules out a perceptual unitization account of the familiarity effect (Silverman, 1985). The familiarity effect was interpreted to be due to the facilitated encoding of a comparison item when a holistic cognitive unit representing the target is activated in memory.     

Sequential effects of phonological priming in visual word recognition

Two masked priming experiments were conducted to examine phonological priming of bisyllabic words in French, and in particular, whether it operates sequentially or in parallel. Bisyllabic target words were primed by pseudowords that shared either the first or the second phonological syllable of the target. Overlap of the first syllable only-not the second-produced facilitation in both the lexical decision and the naming tasks. These findings suggest that, for polysyllabic words, phonological codes are computed sequentially during silent reading and reading aloud.     

Syllabic length effects in visual word recognition and naming

Two experiments investigated the role of the number of syllables in visual word recognition and naming. Experiment 1 (word and nonword naming) showed that effects of number of syllables on naming latencies were observed for nonwords and very low-frequency words but not for high-frequency words. In Experiment 2 (lexical decision), syllabic length effects were also obtained for very low-frequency words but not for high-frequency words and nonwords. These results suggest that visual word recognition and naming do require syllabic decomposition, at least for very low-frequency words in French. These data are compatible with the multiple-trace memory model for polysyllabic word reading [Psychol. Rev. 105 (1998) 678]. In this model, reading depends on the activity of two procedures: (1) a global procedure that operates in parallel across a letter string (and does not generate a strong syllabic length effect) and that is the predominant process in generating responses to high-frequency words, and (2) an analytic procedure that operates serially across a letter string (and generates a strong syllabic length effect) and that is the predominant process in generating responses to very low-frequency words. A modified version of the dual route cascaded model [Psychol. Rev. 108 (1) (2001) 204] can also explain the present results, provided that syllabic units are included in this model. However, the Parallel Distributed Processing model [Psychol. Rev. 96 (1989) 523; J. Exp. Psychol.: Human Perception Perform. 16 (1990) 92] has difficulties to account for these results.     

The time course of similarity effects in visual search

It is well established that visual search becomes harder when the similarity between target and distractors is increased and the similarity between distractors is decreased. However, in models of visual search, similarity is typically treated as a static, time-invariant property of the relation between objects. Data from other perceptual tasks (e.g., categorization) demonstrate that similarity is dynamic and changes as perceptual information is accumulated (Lamberts, 1998). In three visual search experiments, the time course of target-distractor similarity effects and distractor-distractor similarity effects was examined. A version of the extended generalized context model (EGCM; Lamberts, 1998) provided a good account of the time course of the observed similarity effects, supporting the notion that similarity in search is dynamic. Modeling also indicated that increasing distractor homogeneity influences both perceptual and decision processes by (respectively) increasing the rate at which stimulus features are processed and enabling strategic weighting of stimulus information.     

Auditory and visual similarity effects in recognition and recall

The role of auditory and visual factors in short-term recall and recognition performance was evaluated. Auditory similarity, but not visual similarity, was found to be predictive of the probability of a correct response and response confidence for both types of tests. The results were interpreted as support for a single-trace model of recall and recognition performance.     

Semantic access in second-language visual word processing: Evidence from the semantic Simon paradigm

The present study investigated whether visually presented second-language words activate their meaning during low-level word processing, just as native-language words do. Using the semantic Simon paradigm (De Houwer, 1998) with a letter-case judgment task, Dutch-English bilingual participants were instructed to classify targets’ letter case using verbal labels (e.g., by saying “animal” to uppercase targets or “occupation” to lowercase targets). Results showed that both native-language and second-language targets yielded faster responses if the verbal response corresponded to the targets’ semantic category (e.g., the response “animal” to the target LEEUW or LION) than when it did not (e.g., LAWYER), even though the meaning of target words was irrelevant for the task. These results show that second-language word forms may quickly and automatically activate their meaning through strong form-to-meaning mappings, which is consistent with theories of bilingual lexicosemantic organization, such as that of Duyck and Brysbaert (2004).     

Two studies of visual search for word targets with controlled rates of presentation*

The two studies reported involve the visual search of word lists for a target item when the rate of presentation is controlled and the words are presented tachistoscopically. In the first study, the target is differentiated physically from the filler items by being capitalized. When the target is the last item in a list, it is readily identified at all presentation rates, but when it is the first word or is embedded in a list, recognition accuracy is inversely related to presentation rate. In the second study, the differentiation between target and filler items is in terms of the presence or absence of category membership. All Ss at all presentation rates do significantly better on lists with an animal word as a target and a set of unrelated words as filler items than on the converse arrangement.     

Semantic similarity influences early morphological priming in Serbian: A challenge to form-then-meaning accounts of word recognition

Semantically similar (e.g., coolant-COOL) primes have produced greater facilitation than have form-similar but semantically dissimilar (e.g., rampant-RAMP) primes when English words have appeared in the forward-masked primed lexical decision task (Feldman, O'Connor, & Moscoso del Prado Martín, Psychonomic Bulletin & Review 16: 684-691, 2009). These results challenge claims that form-based, semantically blind activation underlies early morphological facilitation. Some have argued that the English materials in previous studies were not ideally constructed, insofar as the types of spelling changes to affixed stems differed in the semantically similar and dissimilar pairs. The present study exploited Serbian's bialphabetism, rich morphology, and homographic (form-identical) stems to replicate early effects of semantic similarity. Furthermore, it incorporated within-target manipulations of prime type and of alphabet, such that the alphabets of the prime-target pairs matched in Experiment 1a and alternated in Experiment 1b. Importantly, no letter or phoneme changes occurred between the stems of the primes and targets. These results revealed significant effects of semantic similarity that are comparable with and without alphabet alternation. The semantic effects in Serbian replicated almost exactly those in English (Feldman et al., Psychonomic Bulletin & Review 16: 684-691, 2009), which suggests that even early in the course of processing, morphemes are units of meaning as well as of form. The results failed to support models of lexical processing that postulate sequential access, first to the morphological form, and then to the semantic aspects of words.