The effects of lexical and semantic information on same-different visual comparison of words

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.     

Orthographic and phonological activation in auditory and visual word recognition

A discrete-trials color naming (Stroop)’paradigm was used to examine activation along orthographic and phonological dimensions in visual and auditory word recognition. Subjects were presented a prime word, either auditorily or visually, followed 200 msec later by a target word printed in a color. The orthographic and phonological similarity of prime-target pairs varied. Color naming latencies were longer when the primes and targets were orthographically and/or phonologically similar than when they were unrelated. This result obtained for both prime presentation modes. The results suggest that word recognition entails activation of multiple codes and priming of orthographically and phonologically similar words.     

The time course of phonological, semantic, and orthographic coding in reading: Evidence from the fast-priming technique

The present experiment employed the fast-priming paradigm in reading (Sereno & Rayner, 1992), in which sentences are silently read while eye-movement-contingent changes are made on a specified target region. In this paradigm, when readers fixate on a specified target word region, a prime word is encountered for a brief duration at the beginning of the fixation and then it is replaced by a target word. Three types of primes were employed:homophones, semantically related, andorthographically similar, and five prime durations were employed: 29, 32, 35, 38, and 41 msec. The primary finding was that significant homophone priming was obtained at prime durations ranging from 29 to 35 msec, whereas significant semantic priming occurred only at the 32-msec prime duration. In contrast, significant orthographic priming occurred at all prime durations. These findings indicate that phonological codes are activated during an eye fixation at least as rapidly as semantic codes. An explanation for the pattern of events is suggested using the framework of an activation-verification model.     

Threshold-style processing of Chinese characters for adult second-language learners

To assess the learning of word form and meaning in an unfamiliar writing system, we carried out primed-naming experiments with learners of Chinese at the end of their first and second terms in a Chinese class at an American university. The subjects were required to name a target Chinese character after a prime character had been presented for 500 msec. There were three priming conditions defined by the relation between the prime and the target: orthographically similar, homophonic, and semantically related. At the end of the first term, there was a significant facilitation for naming speed in the orthographic condition, but not in the homophonic or semantic conditions. However, at the end of the second term, orthographical facilitation disappeared. Instead, naming speed was facilitated by semantically related primes. A threshold-style framework was proposed to illustrate the processing of Chinese orthography, phonology, and semantics by second-language learners.     

Semantic category discrimination and N400

14 subjects performed a semantic category-discrimination task in which they were presented pairs of words and asked to judge whether these belonged to the same category. Three semantic distance conditions, established for the word pairs on the basis of a survey, were semantically close condition (mammals and birds condition) and two semantically distant conditions (mammals and tools condition and birds and tools condition). The reaction times and the percentage of errors were significantly greatest for the mammals and bird condition. There were no significant differences among the three different conditions in N400 latency for target, but the amplitude of N400 tended to be largest for the mammal and bird condition. Comparison N400 of prime and target for each of the conditions showed that the latency for prime was longer than for target in all three conditions.     

Lateralization of lexical codes in auditory word recognition

Three experiments examined the lateralization of lexical codes in auditory word recognition. In Experiment 1 a word rhyming with a binaurally presented cue word was detected faster when the cue and target were spelled similarly than when they were spelled differently. This orthography effect was larger when the target was presented to the right ear than when it was presented to the left ear. Experiment 2 replicated the interaction between ear of presentation and orthography effect when the cue and target were spoken in different voices. In Experiment 3, subjects made lexical decisions to pairs of stimuli presented to the left or the right ear. Lexical decision times and the amount of facilitation which obtained when the target stimuli were semantically related words did not differ as a function of ear of presentation. The results suggest that the semantic, phonological, and orthographic codes for a word are represented in each hemisphere; however, orthographic and phonological representations are integrated only in the left hemisphere.     

Evidence for word length coding during visual word recognition

In a masked priming procedure manipulating orthographic neighbourhood size, the priming word activates a number of word candidates of which the target could be one. Whether the target is one of the candidates or not determines how quickly it is recognised. However, the efficiency of lexical processing may be markedly less if all possible candidates are activated. One solution to this problem is if the visual system uses prime length information to reduce the number of candidates to a more manageable amount. Here, we investigated in two masked priming experiments whether prime length and orthographic information combine to facilitate target word recognition. In Experiment 1, we showed that the efficiency of visual word recognition is not influenced by the length of primes alone. However, when combined with orthographically related primes, word length coding is preserved. In Experiment 2, we investigated whether length priming affects recognition of short and long words differently. Results showed that only short words benefit from a same-length orthographically related prime, and that the priming effect does not generalise to longer words. These results suggest that the length of a word is not an essential feature in lexical processing, but that it can facilitate recognition by constraining the activation of orthographically related words.     

The processing of morpheme-like units in monomorphemic words

The word virus is not normally considered polymorphemic, yet it is clearly both semantically and orthographically related to the word viral. Thus, the subunit vir takes on the role of a bound morpheme. In contrast, the words future and futile also share a subunit (fut), but are semantically unrelated. The reported experiment demonstrates facilitation in a masked priming experiment for the semantically related pairs that share an initial orthographic subunit (e.g., virus-viral), but not for the semantically unrelated pairs (e.g., future-futile). Whether the subunit was pronounced the same way in the prime and target was shown to be irrelevant. Furthermore, semantic relatedness was insufficient to produce priming when orthography was not shared. It was concluded that, while the units of processing within the orthographic system may be the same for the two types of item, their representation at a higher level may depend on the correlation between form with meaning. For example, virus and viral might share a higher level representation and thus facilitate each other, whereas future and futile might be represented separately at that higher level and even compete with each other.     

Expectancy,integration, and interactional processes: Age differences in the nature of words affected by sentence context

Two experiments investigated sentence context effects on the naming times of sentence completion words by third-grade children and college students. Across both experiments, the largest age difference in contextual facilitation was obtained for highly predictable, best completion words. Pronounced age differences in facilitation effects were also present for semantically acceptable target words which were much less predictable in the sentence context than the best completion words. However, age differences in contextual facilitation were negligible for target words which were associatively related to the best completion word, but which were not also semantically acceptable in the sentence context. Thus, the semantic acceptability of the word in the sentence context had a much greater influence on children's as compared to adults' word identification times, both when the word was highly predictable, as well as when it was much less predictable in the sentence context.     

Orthographically mediated inhibition effects: evidence of activational feedback during visual word recognition

Models of visual word recognition that have adopted an interactive activation framework (e.g., Coltheart, Curtis, Atkins, & Haller, 1993; Grainger & Jacobs, 1996) assume that activation can spread from semantic to orthographic representations via a feedback mechanism during visual word recognition. The present study used a mediated priming paradigm to test whether such feedback exists and, if so, under what conditions. Participants named aloud targets that were preceded either by a semantically related prime (e.g., dog-cat) or by a prime that was related to the target via a mediating word (e.g., cat-[dog]-bog). Direct evidence of activational feedback was obtained in the form of orthographically mediated inhibition effects. These mediated inhibition effects are consistent with activational feedback and support models of visual word recognition that have adopted an interactive activation framework.     

Attention and semantic processing during speech: an fMRI study

This fMRI study was conducted to investigate whether language semantics is processed even when attention is not explicitly directed to word meanings. In the “unattended” condition, the subjects performed a visual detection task while hearing semantically related and unrelated word pairs. In the “phoneme” condition, the subjects made phoneme judgements between prime and target words, and in the “word” condition, they indicated whether the words in each word pair were semantically related or unrelated. In the word condition, stronger activity was obtained for unrelated than related words in the superior temporal gyrus/sulcus (STG/STS), lingual/fusiform gyri and cuneus, whereas in the phoneme condition no such effect was observed. However, during the unattended condition, stronger activity was found in the right STG. Our results suggest that both semantic judgement of word pairs and their passive hearing activate the same neural networks but this activation is more restricted in the passive hearing.     

The sound of enemies and friends in the neighborhood

Previous studies (e.g., Pecher, Zeelenberg, & Wagenmakers, 2005) found that semantic classification performance is better for target words with orthographic neighbors that are mostly from the same semantic class (e.g., living) compared to target words with orthographic neighbors that are mostly from the opposite semantic class (e.g., nonliving). In the present study we investigated the contribution of phonology to orthographic neighborhood effects by comparing effects of phonologically congruent orthographic neighbors (book-hook) to phonologically incongruent orthographic neighbors (sand-wand). The prior presentation of a semantically congruent word produced larger effects on subsequent animacy decisions when the previously presented word was a phonologically congruent neighbor than when it was a phonologically incongruent neighbor. In a second experiment, performance differences between target words with versus without semantically congruent orthographic neighbors were larger if the orthographic neighbors were also phonologically congruent. These results support models of visual word recognition that assume an important role for phonology in cascaded access to meaning.     

List context fosters semantic processing: parallels between semantic and morphological facilitation when primes are forward masked

The authors examined patterns of facilitation under forward-masked priming conditions across 3 list contexts (Experiments 1-3) that varied with respect to properties of filler trials -- (a) mixed (morphological, orthographic, semantic), (b) identity, and (c) semantic -- but held the relatedness proportion constant (75%). Facilitation for targets that were related morphologically to their prime occurred regardless of filler context, but facilitation for semantically related pairs occurred only in the context of identity and semantic fillers. Facilitation was absent for orthographically similar prime-target pairs in all 3 filler contexts when matching numbers of orthographically similar word-word and word-nonword prime-target pairs rendered orthographic similarity uninformative with respect to lexicality of the target. Enhanced semantic and morphological facilitation in the context of identity and semantic relative to mixed fillers support a semantically attuned, as contrasted with a purely form-based, account of early morphological processing.     

Age stereotypes in younger and older women: analyses of accommodative shifts with a sentence-priming task

A sentence-priming technique was used to examine whether older women (N = 39) share a more positive view of aging than younger women (N = 35). Situationally specified statements about older and younger persons were presented, followed either by a semantically related word, an unrelated word of the same valence, or a nonword. The accessibility of target words was measured by reaction times in a lexical decision task. Whereas a semantic priming effect for negatively connoted materials emerged for both groups, a priming effect for positively connoted materials was found for older women only. Furthermore, an affective priming effect was found for the older group, i.e., older women tended to respond relatively faster (slower) to semantically unrelated positive (negative) words following a sentence about an older person. The results are discussed within a coping-theoretical framework.     

Priming word recognition with orthographic neighbors: effects of relative prime-target frequency

Four lexical decision experiments were performed with an orthographic priming paradigm in which test words were preceded by orthographically related or unrelated prime words. When prime words were presented for 350 ms without a mask, it was observed that primes that are lower frequency orthographic neighbors of the target interfered with target processing relative to an unrelated condition. When primes were higher frequency neighbors of the target, no interference or facilitation was observed. On the other hand, with briefly presented masked primes, interference was observed with higher frequency prime words. Finally, facilitatory effects in masked repetition priming were obtained with both high- and low-frequency prime-target pairs. The results are interpreted in terms of activation and selection processes operating in visual word recognition.     

The effects of processing requirements on neurophysiological responses to spoken sentences

Ten English speaking subjects listened to sentences that varied in sentential constraint (i.e., the degree to which the context of a sentence predicts the final word of that sentence) and event-related potentials (ERPs) were recorded during the presentation of the final word of each sentence. In the Control condition subjects merely listened to the sentences. In the Orthographic processing condition subjects merely listened to the sentences. In the Orthographic processing condition subjects decided, following each sentence, whether a given letter had been present in the final word of the preceding sentence. In the Phonological processing condition the subjects judged whether a given speech sound was contained in the terminal word. In the Semantic processing condition subjects determined whether the final word was a member of a given semantic category. A previous finding in the visual modality that the N400 component was larger in amplitude for low constraint sentence terminations than for high was extended to the auditory modality. It was also found that the amplitude of a N200-like response was similarly responsive to contextual constraint. The hypothesis that N400 amplitude would vary significantly with the depth of processing of the terminal word was not supported by the data. The "N200" recorded in this language processing context showed the classic frontocentral distribution of the N200. The N400 to spoken sentences had a central/centroparietal distribution similar to the N400 in visual modality experiments. It is suggested that the N400 obtained in these sentence contexts reflects an automatic semantic processing of words that occurs even when semantic analysis is not required to complete a given task. The cooccurrence and topographical dissimilarity of the "N200" and N400 suggest that the N400 may not be a delayed or a generic N200.     

Integration of parafoveal orthographic information during foveal word reading: beyond the sub-lexical level?

Prior research has shown that processing of a given target word is facilitated by the simultaneous presentation of orthographically related stimuli in the parafovea. Here we investigate the nature of such spatial integration processes by presenting orthographic neighbours of target words in the parafovea, considering that neighbours have been shown to inhibit, rather than facilitate, recognition of target words in foveal masked priming research. In Experiment 1, we used the gaze-contingent boundary paradigm to manipulate the parafoveal information subjects received while they fixated a target word within a sentence. In Experiment 2, we used the Flanking Letters Lexical Decision paradigm to manipulate parafoveal information while subjects read isolated words. Parafoveal words were either a higher-frequency orthographic neighbour of targets words (e.g., blue-blur) or a high-frequency unrelated word (e.g., hand-blur). We found that parafoveal orthographic neighbours facilitated, rather than inhibited, processing of the target. Thus, the present findings provide further evidence that orthographic information is integrated across multiple words and suggest that either the integration process does not enable simultaneous access to those words’ lexical representations, or that lexical representations activated by spatially distinct stimuli do not compete for recognition.     

The generalizability of context effects on word recognition: A reconsideration of the roles of parafoveal priming and sentence context

In three experiments, subjects named target words preceded by congruous, incongruous, or neutral sentence contexts. There was no evidence that the recognition of the target word was affected by the semantic characteristics of a word presented immediately to the right of it. The nature of the preceding sentence context did affect target-naming speed. However, the magnitude of the context effect was considerably smaller in these experiments, in which nonterminal target words were used, than in previous experiments in which the target word was always the final word of the sentence, was highly predictable from the context, and was often semantically related to words in the sentence. The implications of these two findings for theories of reading and context effects are discussed.