Automatic activation of phonological information in reading: Evidence from the semantic relatedness decision task

A semantic relatedness decision task was used to investigate whether phonological recoding occurs automatically and whether it mediates lexical access in visual word recognition and reading. In this task, subjects read a pair of words and decided whether they were related or unrelated in meaning. In Experiment 1, unrelated word-homophone pairs (e.g., LION-BARE) and their visual controls (e.g., LION-BEAN) as well as related word pairs (e.g., FISH-NET) were presented. Homophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, suggesting phonological access of word meanings. In Experiment 2, word-pseudohomophone pairs (e.g., TABLE-CHARE) and their visual controls (e.g., TABLE-CHARK) as well as related and unrelated word pairs were presented. Pseudohomophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, again suggesting automatic phonological recoding in reading.     

Lexical ambiguity, semantic context, and visual word recognition.

Some alternative hypotheses about the recognition of ambiguous words are considered. According to the selective-access hypothesis, prior semantic context biases people to access one meaning of an ambiguous word rather than another in lexical memory during recognition. In contrast, the nonselectiveaccess hypothesis states that all meanings of the word are accessed regardless of the context. We tested certain versions of these hypotheses by having students decide whether selected strings of letters were English words. The stimuli included test sequnces of three words in which the second word had two distinct possible meanings, whereas the first and third words were related to these meanings in various ways. When the first and third words were related to the same meaning of the ambiguous second word (e.g., SAVE-BANK-MONEY), the reaction time to recognize the third word decreased. But when the first and third words were related to different meanings of the second word (e.g., RIVER-BANK-MONEY), the reaction time for the third word was not reliably different from a control sequence with unrelated words. These and other data favor the selective-access hypothesis. Selective access to lexical memory is discussed in relation to models of word recognition.     

Learning new vocabulary during childhood: Effects of semantic training on lexical consolidation and integration

Research suggests that word learning is an extended process, with offline consolidation crucial for the strengthening of new lexical representations and their integration with existing lexical knowledge (as measured by engagement in lexical competition). This supports a dual memory systems account, in which new information is initially sparsely encoded separately from existing knowledge and integrated with long-term memory over time. However, previous studies of this type exploited unnatural learning contexts, involving fictitious words in the absence of word meaning. In this study, 5- to 9-year-old children learned real science words (e.g., hippocampus) with or without semantic information. Children in both groups were slower to detect pauses in familiar competitor words (e.g., hippopotamus) relative to control words 24 h after training but not immediately, confirming that offline consolidation is required before new words are integrated with the lexicon and engage in lexical competition. Children recalled more new words 24 h after training than immediately (with similar improvements shown for the recall and recognition of new word meanings); however, children who were exposed to the meanings during training showed further improvements in recall after 1 week and outperformed children who were not exposed to meanings. These findings support the dual memory systems account of vocabulary acquisition and suggest that the association of a new phonological form with semantic information is critical for the development of stable lexical representations.     

Recognizing cognates and interlingual homographs: Effects of code similarity in language-specific and generalized lexical decision

In four experiments, we investigated how cross-linguistic overlap in semantics, orthography, and phonology affects bilingual word recognition in different variants of the lexical decision task. Dutch-English bilinguals performed a language-specific or a generalized lexical decision task including words that are spelled and/or pronounced the same in English and in Dutch and that matched one-language control words from both languages. In Experiments 1 and 3, "false friends" with different meanings in the two languages (e.g., spot) were presented, whereas in Experiments 2 and 4 cognates with the same meanings across languages (e.g., film) were presented. The language-specific Experiments 1 and 2 replicated and qualified an earlier study (Dijkstra, Grainger, & Van Heuven, 1999). In the generalized Experiment 3, participants reacted equally quickly on Dutch-English homographs and Dutch control words, indicating that their response was based primarily on the fastest available orthographic code (i.e., Dutch). In Experiment 4, cognates were recognized faster than English and Dutch controls, suggesting coactivation of the cognates' semantics. The nonword results indicate that the bilingual rejection procedure can, to some extent, be language specific. All results are discussed within the BIA+ (bilingual interactive activation) model for bilingual word recognition.     

When do leotards get their spots? Semantic activation of lexical neighbors in visual word recognition

Shadowing and priming studies have provided strong evidence that during spoken word recognition, the meanings of different words that share their onset (e.g., captain and captive) are activated in parallel. In contrast, for visual word recognition, there is little evidence that the meanings of visually similar words are activated in parallel. This is consistent with the idea that for reading (in contrast to listening), since all the sensory information necessary to identify a word is available at once, any competition between visually similar words is resolved before their meanings are retrieved. However, Forster and Hector (2002) have recently shown that for nonwords (e.g., turple), some aspect of the meanings of lexical neighbors (e.g., turtle) can be activated. However, this finding is limited to non-words. The activation of turtle's meaning in response to turple may occur because turple has no meaning. In normal reading, we do not encounter nonwords, and there is strong pressure on the reading system to produce meaningful representations for every word (even misspelled words). The two semantic categorization experiments reported here extend this finding to real words. Participants are slower to decide that leotard is not an animal because of its animal neighbor leopard. This shows that information about a word's meaning can be available before it has been uniquely recognized.     

Ambiguity Advantage Revisited: Two Meanings are Better than One When Accessing Chinese Nouns

This paper revisits the effect of lexical ambiguity in word recognition, which has been controversial as previous research reported advantage, disadvantage, and null effects. We discuss factors that were not consistently treated in previous research (e.g., the level of lexical ambiguity investigated, parts of speech of the experimental stimuli, and the choice of non-words) and report on a lexical decision experiment with Chinese nouns in which ambiguous nouns with homonymic and/or metaphorical meanings were contrasted with unambiguous nouns. An ambiguity advantage effect was obtained—Chinese nouns with multiple meanings were recognized faster than those with only one meaning. The results suggested that both homonymic and metaphorical meanings are psychologically salient semantic levels actively represented in the mental lexicon. The results supported a probability-based model of random lexical access with multiple meanings represented by separate semantic nodes. We further discuss these results in terms of lexical semantic representation and how different experimental paradigms result in different ambiguity effects in lexical access.     

Effects of relative embodiment in lexical and semantic processing of verbs

Research examining semantic richness effects in visual word recognition has shown that multiple dimensions of meaning are activated in the process of word recognition (e.g., Yap et al., 2012). This research has, however, been limited to nouns. In the present research we extended the semantic richness approach to verb stimuli in order to investigate how verb meanings are represented. We characterized a dimension of relative embodiment for verbs, based on the bodily sense described by Borghi and Cimatti (2010), and collected ratings on that dimension for 687 English verbs. The relative embodiment ratings revealed that bodily experience was judged to be more important to the meanings of some verbs (e.g., dance, breathe) than to others (e.g., evaporate, expect). We then tested the effects of relative embodiment and imageability on verb processing in lexical decision (Experiment 1), action picture naming (Experiment 2), and syntactic classification (Experiment 3). In all three experiments results showed facilitatory effects of relative embodiment, but not imageability: latencies were faster for relatively more embodied verbs, even after several other lexical variables were controlled. The results suggest that relative embodiment is an important aspect of verb meaning, and that the semantic richness approach holds promise as a strategy for investigating other aspects of verb meaning.     

Semantic, phonological, and mediated priming in reading and lexical decisions

Four experiments were conducted to investigate whether semantic activation of a concept spreads to phonologically and graphemically related concepts. In lexical decision or self-paced reading tasks, subjects responded to pairs of words that were semantically related (e.g., light-lamp), that rhymed (e.g., lamp-damp), or that combined both of these relations through a mediating word (e.g., light-damp). In one version of each task, test lists contained word-word pairs (e.g., light-lamp) as well as nonword-word (e.g., pown-table) and word-nonword pairs (e.g., month-poad); in another version, test lists contained only word-word pairs. The lexical decision and self-paced reading tasks were facilitated by semantic and rhyming relations regardless of the presence or absence of nonwords on the test lists. The effect of the mediated relation, however, depended on the presence of nonwords among the stimuli. When only words were included, there was no effect of the mediated relation, but when nonwords were included, lexical decision and self-paced reading responses were inhibited by the mediated relation. These inhibitory effects are attributed to processes occurring after lexical access, and the relative advantages of the self-paced reading task are discussed.     

Eye movements and brain electric potentials during reading

The development of theories and computational models of reading requires an understanding of processing constraints, in particular of timelines related to word recognition and oculomotor control. Timelines of word recognition are usually determined with event-related potentials (ERPs) recorded under conditions of serial visual presentation (SVP) of words; timelines of oculomotor control are derived from parameters of eye movements (EMs) during natural reading. We describe two strategies to integrate these approaches. One is to collect ERPs and EMs in separate SVP and natural reading experiments for the same experimental material (but different subjects). The other strategy is to co-register EMs and ERPs during natural reading from the same subjects. Both strategies yield data that allow us to determine how lexical properties influence ERPs (e.g., the N400 component) and EMs (e.g., fixation durations) across neighboring words. We review our recent research on the effects of frequency and predictability of words on both EM and ERP measures with reference to current models of eye-movement control during reading. Results are in support of the proposition that lexical access is distributed across several fixations and across brain-electric potentials measured on neighboring words.     

Interhemispheric communication via direct connections for alternative meanings of ambiguous words

A priming experiment was used to investigate Burgess and Simpson's (1988) claim that interhemispheric cooperation plays an essential role in the interpretation of ambiguous text. In doing so, the merits of two models of interhemispheric cooperation, the homotopic inhibition theory (Cook, 1986) and the direct connections model (Collins & Coney, 1998), were examined. Priming of alternative meanings of ambiguous words was measured using homographs and their dominant (e.g., BARK-DOG) and subordinate meanings (e.g., BARK-TREE) as related pairs in a lexical decision task, with normal university students as subjects. Stimulus pairs were temporally separated by stimulus onset asynchronies (SOAs) of 180 and 350 ms and were independently projected to the left or right visual fields (LVF or RVF). At the shorter SOA, priming was restricted to LVF-RVF presentations, with homograph primes directed to the LVF equally facilitating responses to RVF targets which were associated with their dominant and subordinate meanings. This suggests that within 180 ms, a homograph projected to the right hemisphere activates a range of alternative meanings in the left hemisphere. At an SOA of 350 ms, LVF-RVF priming was obtained along with RVF-LVF and RVF-RVF priming. Evidently at this stage of processing, an ambiguous word directed to either hemisphere activates a range of alternative meanings in the contralateral hemisphere, while RVF primes also activate subordinate, but not dominant meanings in the left hemisphere. A homograph directed to the LVF did not activate dominant or subordinate meanings within the right hemisphere at either SOA. Generally, ambiguous words directed to either hemisphere activated a more extensive array of meanings in the contralateral hemisphere than in the hemisphere to which the prime was directed. This confirms the importance of interhemispheric cooperation in generating alternate meanings of ambiguous words. Strong support was found for the direct connections model (Collins & Coney, 1998), but no support for the homotopic inhibition theory (Cook, 1986).     

Phonological recoding and context

This paper reports an experiment in which lexical decision times for words with irregular spelling-to-sound correspondence (e.g., GAUGE) and matched regular words (e.g., GRILL) were measured under two conditions: priming, in which each target was preceded by a semantically related word, and a control condition, in which each target was preceded by an asterisk. The results showed that lexical decision times were significantly longer for irregular words and that lexical decision times were significantly faster in the priming condition. There was no interaction between these two factors, indicating that these two variables have an additive effect on lexical decision speed. The experiment therefore extends the range of conditions under which word regularity effects can be demonstrated and suggests that the phonological component of the lexical access process is uninfluenced by the provision of semantic context. The nature of regularity effects with regard to lexical decision is also briefly discussed.     

Lexical search speed in children and adults

The retrieval of words from lexical memory was investigated in kindergartners (Age 6), first-graders (Age 7), third-graders (Age 9), and adults. A lexical decision task with auditorily presented words and nonwords was used, with decision latency as the dependent variable. Multiple regression analyses were used to examine the effects of word frequency, age of word acquisition, and number of word meanings. Results showed that word frequency contributed to decision latency for all age groups, age of word acquisition contributed to all groups but the third-grade subjects, and number of word meanings did not contribute for any age group. Results are discussed in relation to a model of the lexicon in children and adults. It is suggested that factors from the external linguistic community are internalized in the lexicon at an early age.     

Testing the direct-access model: GOD does not prime DOG

In three repetition priming experiments that employed identical (e.g., DOG-DOG) and reversed repetitions (e.g., GOD-DOG), it was found that relative to controls (e.g., DOG-DOG), GOD-type words did not prime DOG-type words. Also, neither DUT-type nor TUD-type nonwords primed DUT-type nonwords. In Experiments 1 and 2, these results occurred using both long- and short-term repetition priming conditions, respectively. In Experiment 3, the word results held under conditions of short-term priming coupled with stimulus misorientation. However, the nonword results resembled the word results (i.e., identical but not reversed repetitions primed nonwords). The failure to provide explicit evidence for direct visual access (e.g., GOD does not prime DOG while DOG does) irrespective of other sources of lexical activation supports theories of word recognition that postulate multiple and varied lexical representations that are activated through a matrix of connections.     

Allomorphic variation in Arabic: implications for lexical processing and representation

This study probes the effects of allomorphy on access to Arabic roots and word patterns in two cross-modal priming experiments. Experiment 1 used strong roots which undergo no allomorphy, and weak roots which undergo allomorphy and surface with only two of their three consonants in some derivations. Word pairs sharing a root morpheme prime each other reliably not only when the root was strong (e.g., [see text] participant/participate), but also when it was weak (e.g., [see text] agreement-agree, where the weak root [wfq] surfaces fully in the target but not the prime). This facilitation occurred even when the weak root surfaced with different semantic meanings across prime and target (e.g., [see text] destination/confront). Experiment 2 assessed the effects of allomorphy on word pattern processing, comparing word pairs where the word pattern is transparently realised in both prime and target (e.g., [see text] spread/bear], with pairs which share the same underlying word pattern but where a weak root triggers an assimilation process in the prime (e.g., [see text] unite/smile). This assimilation process does not disrupt the CV-structure of the word pattern, in contrast to a third condition where this is disrupted in both prime and target (e.g., [see text] turn around/say). Strong priming effects were observed in the first two conditions but not in the third. The bearing of these findings on models of lexical processing and representation is discussed.     

Grasping the invisible: Semantic processing of abstract words

The problem of how abstract word meanings are represented has been a challenging one. In the present study, we extended the semantic richness approach (e.g., Yap, Tan, Pexman, & Hargreaves in Psychonomic Bulletin & Review 18:742–750, 2011) to abstract words, examining the effects of six semantic richness variables on lexical–semantic processing for 207 abstract nouns. The candidate richness dimensions were context availability (CA), sensory experience rating (SER), valence, arousal, semantic neighborhood (SN), and number of associates (NoA). The behavioral tasks were lexical decision (LDT) and semantic categorization (SCT). Our results showed that the semantic richness variables were significantly related to both LDT and SCT latencies, even after lexical and orthographic factors were controlled. The patterns of richness effects varied across tasks, with CA effects in the LDT, and SER and valence effects in the SCT. These results provide new insight into how abstract meanings may be grounded, and are consistent with a dynamic, multidimensional framework for semantic processing.     

The effect of polysemy on lexical decision time: Now you see it,now you don’t

Gernsbacher (1984) found that number of word meanings (polysemy) did not influence lexical decision time when it was operationalized as number of dictionary definitions. This finding supports her contention that subjects do not store all possible dictionary meanings for words in memory. The present experiments extended Gernsbacher's research by determining whether more psychologically valid measures of polysemy affect lexical decision time. Three metrics were used to represent the meanings that subjects actually access from memory (accessible polysemy): (1) the first meanings subjects think of when asked to define stimulus words, (2) all the meanings subjects generate for words, and (3) the average number of meanings subjects generate. The results showed that the second and third metrics of polysemy influenced lexical decision time, whereas the first metric (representing mostly the access to dominant meanings for words) only approached significance.     

Phonological processing and lexical access in aphasia

This study explored the relationship between on-line processing of phonological information and lexical access in aphasic patients. A lexical decision paradigm was used in which subjects were presented auditorily with pairs of words or word-like stimuli and were asked to make a lexical decision about the second stimulus in the pair. The initial phonemes of the first word primes, which were semantically related to the real word targets, were systematically changed by one or more than one phonetic feature, e.g., cat-dog, gat-dog, wat-dog. Each of these priming conditions was compared to an unrelated word baseline condition, e.g., nurse-dog. Previous work with normals showed that even a nonword stimulus receives a lexical interpretation if it shares a sufficient number of phonetic features with an actual word in the listener's lexicon. Results indicated a monotonically decreasing degree of facilitation as a function of phonological distortion. In contrast, fluent aphasics showed priming in all phonological distortion conditions relative to the unrelated word baseline. Nonfluent aphasics showed priming only in the undistorted, related word condition relative to the unrelated word baseline. Nevertheless, in a secondary task requiring patients to make a lexical decision on the nonword primes presented singly, all aphasics showed phonological feature sensitivity. These results suggest deficits for aphasic patients in the various processes contributing to lexical access, rather than impairments at the level of lexical organization or phonological organization.     

Effects of syntactic category assignment on lexical ambiguity resolution in reading: an eye movement analysis

Readers' eye movements were monitored as they read sentences containing lexically ambiguous words whose meanings share a single syntactic category (e.g., calf), lexically ambiguous words whose meanings belong to different syntactic categories (e.g., duck), or unambiguous control words. Information provided prior to the target always unambiguously specified the context-appropriate syntactic-category assignment for the target. Fixation times were longer on ambiguous words whose meanings share a single syntactic category than on controls, both when prior context was semantically consistent with the subordinate interpretation of a biased ambiguous word (Experiment 1) and when prior context was semantically neutral as to the intended interpretation of a balanced ambiguous word (Experiment 2). These ambiguity effects, which resulted from differences in difficulty with meaning resolution, were not found when the ambiguity crossed syntactic categories. These data indicate that, in the absence of syntactic ambiguity, syntactic-category information mediates the semantic-resolution process.     

Is phonological information mapped onto semantic information in a one-to-one manner?

Spoken word recognition models have to explain the influence of mismatching information on lexical activation. The effect of mismatching information is usually addressed with cross-modal semantic priming experiments using priming effects as a measure of the degree of lexical activation. Pseudowords phonologically related to a semantic associate of the target, e.g., *domato-PAPRIKA, serve as primes. Mismatch effects at the word form level are supposed to percolate unaltered to the semantic level. We show that cross-modal semantic priming might underestimate activation at the word form level. Targets (e.g., PAPRIKA) were preceded by either phonologically related pseudoword primes (e.g., *baprika) or semantically related pseudoword primes (e.g., *domato). Different priming and RT patterns were obtained for the two priming relations.