Rapid activation of the lexicon: a further investigation with behavioral and computational results

Priming effects were observed in a categorization task for both prime-target synonym pairs (e.g., boat-ship) and first-associate pairs (e.g., boat-sea). However, the amount and onset of priming were different for synonyms and associated pairs. The effect appeared sooner for synonyms (at prime duration of 43 ms) than for associated words (57 ms onset) but was present for both these relationships at 71 ms of prime presentation. A prime visibility pretest was conducted with the same participants in order to determine the rate of recognition of our prime words. Last, a French matrix of the HAL model was built, which showed that synonyms pairs were semantically closer than associated pairs. These results are in accordance with our previous study (Frenck-Mestre & Bueno, 1999) and are discussed in relation with semantic models, such as Plaut's (1995) distributed model.     

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.     

What do graded effects of semantic transparency reveal about morphological processing?

We examined the influence of semantic transparency on morphological facilitation in English in three lexical decision experiments. Decision latencies to visual targets (e.g., CASUALNESS) were faster after semantically transparent (e.g., CASUALLY) than semantically opaque (e.g., CASUALTY) primes whether primes were auditory and presented immediately before onset of the target (Experiment 1a) or visual with an stimulus onset asynchrony (SOA) of 250 ms (Experiment 1b). Latencies did not differ at an SOA of 48 ms (Experiment 2) or with a forward mask at an SOA of 83 ms (Experiment 3). Generally, effects of semantic transparency among morphological relatives were evident at long but not at short SOAs with visual targets, regardless of prime modality. Moreover, the difference in facilitation after opaque and transparent primes was graded and increased with family size of the base morpheme.     

The effect of asymmetrical association on positive and negative semantic priming

One's actively ignoring a stimulus can impair subsequent responding to that stimulus. This negative priming effect has been argued to generalize to semantically related items as well, but the evidence for this is still somewhat weak. This article presents a new experiment in which participants made lexical decisions to asymmetrically associated prime-target pairs presented in either the forward (e.g., stork-baby) or backward (e.g., baby-stork) direction. The critical new finding was that both attended positive and ignored negative semantic priming occurred only for prime-target pairs presented in the forward direction. The results support either (1) a spreading inhibition model in which items associated with an ignored distractor are inhibited during prime selection or (2) a version of episodic retrieval theory in which the prime distractor and items associated with it are tagged as "to-be-ignored" during prime selection.     

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.     

Automatic semantic feedback during visual word recognition

Four experiments were conducted to determine whether semantic feedback spreads to orthographic and/or phonological representations during visual word recognition and whether such feedback occurs automatically. Three types of prime-target word pairs were used within the mediated-priming paradigm: (1) homophonically mediated (e.g., frog-[toad]-towed), (2) orthographically mediated (e.g., frog-[toad]-told), and (3) associatively related (e.g., frog-toad). Using both brief (53 msec; Experiment 1) and long (413 msec; Experiment 3) prime exposure durations, significant facilitatory-priming effects were found in the response time data with orthographically, but not homophonically, mediated prime-target word pairs. When the prime exposure duration was shortened to 33 msec in Experiment 4, however, facilitatory priming was absent with both orthographically and homophonically mediated word pairs. In addition, with a brief (53-msec) prime exposure duration, direct-priming effects were found with associatively (e.g., frog-toad), orthographically (e.g., toad-told), and homophonically (e.g., toad-towed) related word pairs in Experiment 2. Taken together, these results indicate that following the initial activation of semantic representations, activation automatically feeds back to orthographic, but not phonological, representations during the early stages of word processing. These findings were discussed in the context of current accounts of visual word recognition.     

Automatic Semantic Priming: The Contribution of Lexical- and Semantic-level Processes

It has recently been argued that the facilitation between associated primetarget pairs observed in automatic semantic priming tasks is due to lowlevel lexical effects. Any ''pure'' semantic priming is thought to be the result of strategic effects and does not therefore reflect automatic access to lexical semantic representations (e.g. Shelton & Martin, 1992). Not only are such claims based on a narrow definition of semantic relatedness as category comembership, but it is argued that the methodology employed by Shelton and Martin and other advocates of the intra-lexical priming hypothesis, who have attempted to dissociate semantic and associative effects by devising non-associated semantic prime-target pairs, is fundamentally flawed. Instead, an experiment is reported in which purely lexical-level primes are compared directly with semantic-level primes for the same target items in a sequential lexical decision task. Both types of prime produce facilitation, but only that from the semantic-level primes is significant. It is argued that, contrary to the intra-lexical priming hypothesis, semantic information is required for automatic semantic priming. If it were not, the lexical-level priming in this experiment would have been greater than the semantic-level priming. As it is, the reverse pattern is reported, providing support for the notion of a semantic contribution to the facilitation observed between associated prime-target pairs.     

Semantic facilitation in lexical decision as a function of prime-target association

Using a lexical decision task, the relationship between magnitude of semantic facilitation and degree of prime-target relatedness was examined as a function of amount of attention allocated to the prime and the prime-target interval. In none of the conditions studied did amount of facilitation vary with prime-target relatedness, a finding which was seen as inconsistent with the spread of activation account of the association effect in lexical decision. Both forward (prime to target) and backward (target to prime) associations were effective in producing semantic facilitation. Backward associates, however, were effective only during earlier stages of the experiment and forward associations only during later stages. The implications of these findings for the processes underlying the association effect was discussed.     

Automatic semantic priming in the left and right hemispheres

We investigated hemispheric differences and inter-hemispheric transfer of facilitation in automatic semantic priming, using prime-target pairs composed of words of the same category but not associated (e.g. skirt-glove), and a blank-target baseline condition. Reaction time and accuracy were measured at short (300 ms) intervals between prime and target onsets, using a go/no-go task to discriminate between word or non-word targets. Reaction times were facilitated more for target words presented in the right visual field (RVF) compared to the left visual field (LVF), and targets presented in RVF were primed in both visual fields, whereas targets presented in LVF were primed by primes in the LVF only. These results suggest that both hemispheres are capable of automatic priming at very short stimulus onset asymmetries (SOA), but cross-hemisphere priming occurs only in the left hemisphere.     

Morphological processing: a comparison between free and bound stem facilitation

Linguists distinguish between words formed from free stems (e.g., actor: act) and those formed from bound stems (e.g., spectator: spect). In a forward masked priming task, we observed significant morphological facilitation for prime-target pairs that shared either a free (e.g., deform-CONFORM) or a bound (e.g., revive-SURVIVE) stem. Relative to an unrelated baseline, magnitudes of facilitation for free (e.g., form) and bound (e.g., vive) stems were significant and comparable, but relative to an orthographic baseline free stem facilitation was greater than bound stem facilitation. In addition, the magnitude of bound (but not free) stem morphological facilitation correlated with the number of morphological relatives.     

Semantic priming,prime reportability,and retroactive priming are interdependent

In two experiments, semantic analysis of prime words was measured in terms of facilitation in naming a semantically related target word. Targets were degraded but gradually clarified until the subject named them. Subjects reported the prime after naming the target. Experiment 1 used semantic associates as primes at a 50-msec prime-target stimulus onset asynchrony (SOA). Experiment 2 used both semantic-associate and identity primes at a 1,000-msec prime-target SOA. Reported primes showed facilitation in both experiments, whereas unreported primes did not. It appears that primes that undergo enough analysis to facilitate target processing are also available for conscious report. However, retroactive priming in both experiments showed that target processing also had an impact on prime reportability. The interdependence of priming and prime reportability disallows a straightforward interpretation of the origin of the facilitation.     

Low-constraint facilitation in lexical decision with single-word contexts

Single-word, low-constraint adjective contexts were used to "prime" lexical decision to noun targets in Serbo-Croat. Semantically congruent situations consisted of adjective-noun pairs that were not highly predictable but were nonetheless plausible (e.g., GOOD-AUNT). Semantically incongruent situations used pairs that were implausible (e.g., SLOW-COAT). All adjective-noun pairs were grammatically congruent and were compared with a neutral XXX baseline. In Experiment 1, at a stimulus onset asynchrony of 300 ms, congruous situations showed 59 ms of facilitation while incongruous situations did not differ from the baseline. The same pattern was repeated in Experiment 2, at a stimulus onset asynchrony of 800 ms. Congruous situations were facilitated 67 ms. Results are discussed in terms of a message-level coherence check in Forster's (1979) model of autonomous levels of language processing.     

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.     

The effects of associative and semantic priming in the lexical decision task

Four lexical decision experiments were conducted to examine under which conditions automatic semantic priming effects can be obtained. Experiments 1 and 2 analyzed associative/semantic effects at several very short stimulus-onset asynchronies (SOAs), whereas Experiments 3 and 4 used a single-presentation paradigm at two response-stimulus intervals (RSIs). Experiment 1 tested associatively related pairs from three semantic categories (synonyms, antonyms, and category coordinates). The results showed reliable associative priming effects at all SOAs. In addition, the correlation between associative strength and magnitude of priming was significant only at the shortest SOA (66 ms). When prime-target pairs were semantically but not associatively related (Experiment 2), reliable priming effects were obtained at SOAs of 83 ms and longer. Using the single-presentation paradigm with a short RSI (200 ms, Experiment 3), the priming effect was equal in size for associative + semantic and for semantic-only pairs (a 21-ms effect). When the RSI was set much longer (1,750 ms, Experiment 4), only the associative + semantic pairs showed a reliable priming effect (23 ms). The results are interpreted in the context of models of semantic memory.     

Semantic and associative priming in picture naming

We report four picture-naming experiments in which the pictures were preceded by visually presented word primes. The primes could either be semantically related to the picture (e.g., "boat" - TRAIN: co-ordinate pairs) or associatively related (e.g., "nest" - BIRD: associated pairs). Performance under these conditions was always compared to performance under unrelated conditions (e.g., "flower" - CAT). In order to distinguish clearly the first two kinds of prime, we chose our materials so that (a) the words in the co-ordinate pairs were not verbally associated, and (b) the associate pairs were not co-ordinates. Results show that the two related conditions behaved in different ways depending on the stimulus-onset asynchrony (SOA) separating word and picture appearance, but not on how long the primes were presented. When presented with a brief SOA (114 ms, Experiment 1), the co-ordinate primes produced an interference effect, but the associated primes did not differ significantly from the unrelated primes. Conversely , with a longer SOA (234 ms, Experiment 2) the co-ordinate primes produced no effect, whereas a significant facilitation effect was observed for associated primes, independent of the duration of presentation of the primes. This difference is interpreted in the context of current models of speech production as an argument for the existence, at an automatic processing level, of two distinguishable kinds of meaning relatedness.     

Predicting semantic priming at the item level

The current study explores a set of variables that have the potential to predict semantic priming effects for 300 prime-target associates at the item level. Young and older adults performed either lexical decision (LDT) or naming tasks. A multiple regression procedure was used to predict priming based upon prime characteristics, target characteristics, and prime-target semantic similarity. Results indicate that semantic priming (a) can be reliably predicted at an item level; (b) is equivalent in magnitude across standardized measures of priming in LDTs and naming tasks; (c) is greater following quickly recognized primes; (d) is greater in LDTs for targets that produce slow lexical decision latencies; (e) is greater for pairs high in forward associative strength across tasks and across stimulus onset asynchronies (SOAs); (f) is greater for pairs high in backward associative strength in both tasks, but only at a long SOA; and (g) does not vary as a function of estimates from latent semantic analysis (LSA). Based upon these results, it is suggested that researchers take extreme caution in comparing priming effects across different item sets. Moreover, the current findings lend support to spreading activation and feature overlap theories of priming, but do not support priming based upon contextual similarity as captured by LSA.     

Automatic and strategic effects in semantic priming: An examination of Becker’s verification model

Becker’s (1980) verification model, in conjunction with a two-strategy hypothesis, is cited as an alternative to a dual-process model (e.g., Posner & Snyder, 1975) of word recognition and semantic priming. Becket’s approach suggests that individuals can use either an “expectancy” or a “prediction” strategy in word recognition, and maintains that the verification model successfully predicts certain patterns of facilitation and inhibition in a semantic priming task that a dual-process model cannot. The present study demonstrated that when a long stimulus-onset asynchrony (SOA = 1,000 msec) is used between prime and target, support is given to Becker’s findings, and to the verification model approach. However, at a short SOA (200 msec), no evidence is found for the hypothesized difference between strategic processes. The results are consistent with other findings (e.g., Neely, 1977) in showing that strategic factors in semantic priming are largely inoperative at short prime-target SOAs, and suggests that Becker’s model is not general enough to rule out some type of dual-process model.     

Automatic semantic priming with various category relations in Alzheimer's disease and normal aging.

The 6 experiments reported here tested the effects of various category relations on automatic semantic priming in 20 Alzheimer's disease (AD), 20 older control, and 22 younger control subjects. The tasks were either word pronunciation or lexical decision; the prime-target stimulus-onset asynchrony (SOA) was always 250 ms. A variety of category relationships between prime and target were examined: highly associated category comembers, subordinate-superordinate or superordinate-subordinate pairs, and pairs selected on the basis of category typically to form typical-typical, atypical-typical, typical-atypical, and atypical-atypical pairings. Both for AD versus older control subjects and for older versus younger control subjects, no significant group differences were found in the magnitude of overall semantic priming or in the effects on priming of factors pertaining to the prime-target relationship.     

Effects of semantic context and event-related potentials: N400 correlates with inhibition effect

Two experiments investigated the modulation of event-related brain potentials (ERPs) by semantic context. A prime-target pair was visually presented in each trial of a lexical decision task. For word targets, three types of relatedness conditions were employed: (1) Related word condition (e.g., school-teacher); (2) Neutral word condition (e.g., [symbol: see text] - number); (3) Unrelated word c((e.g., hospital-potato). In Experiment 1, the reaction time for unrelated targets was longer than that for neutral targets (inhibition effect) which was longer than that for related targets (facilitation effect). The N400 amplitude in the unrelated targets was larger compared to those in the related and neutral targets, which did not differ. In Experiment 2, where only the facilitation effect was obtained, the N400 amplitude did not differ among conditions.     

Dissociative affective and associative priming effects in the lexical decision task: yes versus no responses to word targets reveal evaluative judgment tendencies

The affective priming effect (AP; i.e., shorter evaluative or lexical decision latencies for affectively congruent prime-target pairs) has often been interpreted as evidence for spreading activation from the prime to affectively congruent targets. The present study emphasizes the view that in the lexical decision task, the prime-target configuration is implicitly evaluated as a question of the form "Is (prime) (target)?" (e.g., "Is death wise?") so that there is a tendency to affirm in cases of congruency and to negate in cases of incongruency. Therefore, after establishing the AP with the lexical decision task in Experiment 1, in Experiment 2 the assignment of yes responses to words and nonwords was varied. For the word = yes condition, the AP emerged, whereas the data pattern was reversed for the word = no condition. In Experiment 3, a comparable pattern of results was not found for symmetrical or backward associatively related prime-target pairs.