Semantic representations of word meanings by the cerebral hemispheres

Two priming experiments investigated kind and strength of semantic knowledge underlying known, frontier, and unknown low frequency words. Results from Experiment 1 suggest that known words reflect categorical knowledge, but frontier and unknown words reflect thematic knowledge. Thematic knowledge for frontier words appears to be stronger than that for unknown words. Experiment 2 entailed visual half-field presentation of targets. All facilitory effects were restricted to the lvf/RH, and inhibitory effects to the rvf/LH. Experiment 1 findings were mirrored by the RH. Thematic knowledge appears to precede categorical knowledge for the RH, but the opposite may be true of the LH. Results are also discussed in terms of the RH role in meaning acquisition and metacontrol.     

The acquisition of morphological knowledge investigated through artificial language learning

Affix knowledge plays an important role in visual word recognition, but little is known about how it is acquired. The authors present a new method of investigating the acquisition of affixes in which participants are trained on novel affixes presented in novel word contexts (e.g., sleepnept). Experiment 1 investigated the role of semantic information on affix acquisition by comparing a form-learning condition with a condition in which participants also received definitions for each novel word. Experiment 2 investigated the role of long-term consolidation on affix acquisition by comparing knowledge of learned affixes two days and nearly two months after training. Results demonstrated that episodic knowledge of affixes can be acquired shortly after a single training session using either form or semantic learning, but suggested that the development of lexicalized representations of affixes requires the provision of semantic information during learning as well as a substantial period of offline consolidation.     

The concurrent use of three implicit measures (eye movements,pupillometry, and event-related potentials) to assess receptive vocabulary knowledge in normal adults

Recent years have seen the advent and proliferation of the use of implicit techniques to study learning and cognition. One such application is the use of event-related potentials (ERPs) to assess receptive vocabulary knowledge. Other implicit assessment techniques that may be well-suited to other testing situations or to use with varied participant groups have not been used as widely to study receptive vocabulary knowledge. We sought to develop additional implicit techniques to study receptive vocabulary knowledge that could augment the knowledge gained from the use of the ERP technique. Specifically, we used a simple forced-choice paradigm to assess receptive vocabulary knowledge in normal adult participants using eye movement monitoring (EM) and pupillometry. In the same group of participants, we also used an N400 semantic incongruity ERP paradigm to assess their knowledge of two groups of words: those expected to be known to the participants (high-frequency, familiar words) and those expected to be unknown (low-frequency, unfamiliar words). All three measures showed reliable differences between the known and unknown words. EM and pupillometry thus may provide insight into receptive vocabulary knowledge similar to that from ERPs. The development of additional implicit assessment techniques may increase the feasibility of receptive vocabulary testing across a wider range of participant groups and testing situations, and may make the conduct of such testing more accessible to a wider range of researchers, clinicians, and educators.     

Lexical leverage: category knowledge boosts real‐time novel word recognition in 2‐year‐olds

Recent research suggests that infants tend to add words to their vocabulary that are semantically related to other known words, though it is not clear why this pattern emerges. In this paper, we explore whether infants leverage their existing vocabulary and semantic knowledge when interpreting novel label–object mappings in real time. We initially identified categorical domains for which individual 24‐month‐old infants have relatively higher and lower levels of knowledge, irrespective of overall vocabulary size. Next, we taught infants novel words in these higher and lower knowledge domains and then asked if their subsequent real‐time recognition of these items varied as a function of their category knowledge. While our participants successfully acquired the novel label–object mappings in our task, there were important differences in the way infants recognized these words in real time. Namely, infants showed more robust recognition of high (vs. low) domain knowledge words. These findings suggest that dense semantic structure facilitates early word learning and real‐time novel word recognition.     

Practice makes perfect: Training the interpretation of emotional ambiguity

The interpretation of emotionally ambiguous words, sentences, or scenarios can be altered through training procedures that are collectively called cognitive bias modification for interpretation (CBM-I). In three experiments, we systematically manipulated the nature of the training in order to discriminate between emotional priming and ambiguity resolution accounts of training effects. In Experiment 1 participants completed word fragments that were consistently related to either a negative or benign interpretation of an ambiguous sentence. In a subsequent semantic priming task they demonstrated an interpretation bias, in that they were faster to identify relatedness of targets that were associated with the training-congruent meaning of an emotionally ambiguous homograph. We then manipulated the training sentences to show that interpretation bias was eliminated when participants simply completed valenced word fragments following unrelated sentences (Experiment 2), or completed fragments that were related to emotional but unambiguous sentences (Experiment 3). Only when participants were required to actively resolve emotionally ambiguous sentences during training did changes in interpretation emerge at test. Findings suggest that CBM-I achieves its effects by altering a production rule that aids the selection of meaning from emotionally ambiguous alternatives, in line with an ambiguity resolution account.     

The right hemisphere maintains solution-related activation for yet-to-be-solved problems

In five experiments, we examined the time course of hemispheric differences in solution activation for insight-like problems. We propose that solving insight problems requires retrieval of unusual interpretations of problem elements, and that right-hemisphere (RH) coarse semantic coding is more likely than left-hemisphere (LH) fine semantic coding to maintain semantic activation of such interpretations. In four experiments, participants attempted word problems for 7 sec (Experiments 1A and 1B) or 2 sec (Experiments 2A and 2B), and 750 msec later responded to lateralized target words. After 7 sec of solving effort, Experiment 1A participants showed greater solution-related priming (i.e., they named solutions faster than unrelated words) for left visual field-RH (lvf-RH) targets than for right visual field-LH (rvf-LH) targets, and Experiment 1B participants made faster solution decisions on target words presented to the RH, as previously demonstrated following 15 sec of effort. After 2 sec of solving effort in Experiment 2A, women showed symmetric solution-related priming, although men showed a slight lvf-RH advantage in priming; and in Experiment 2B participants made equally quick solution decisions for targets presented to the LH and to the RH. In Experiment 3, participants viewed the problems for 1,250 msec then named lateralized target words; they showed symmetric solution-related priming. These experiments demonstrate solution activation initially in both hemispheres, but maintained solution activation only in the RH.     

Robust affective priming effects in a conditional pronunciation task: Evidence for the semantic representation of evaluative information

Based on the hypothesis that information about the valence of words is encoded in a semantic system, we predicted that the match between the valence of a prime and the valence of a target word will influence the pronunciation of the target only if and to the extent that pronunciation is semantically mediated. In line with this prediction, we found affective priming effects (faster pronunciation when prime and target had the same valence than when they had a different valence) only when participants were instructed to read words but not nonwords (Experiment 1) or words that were not names of occupations (Experiment 2). Priming was not significant when participants were asked to read white but not red words (Experiment 1) or words that did not have a frame around them (Experiment 2).     

Partial word knowledge in the absence of recall

Attributes of words can be known even when the words are not currently retrievable. Although repeatedly demonstrated for semantic and contextual dimensions, the evidence is ambiguous for structural characteristics. The present research demonstrates significant above-chance first-letter knowledge across four ordinal levels of retrieval confidence for nonretrieved words—tip of the tongue (TOT), high familiar, low familiar, unfamiliar. Contrary to prior research, there was minimal evidence for syllable number knowledge, even at highest confidence levels. Initial letter recognition in the absence of retrieval resembles the recognition without identification in episodic memory (Cleary, Current Directions in Psychological Science 17: 353–357, 2008), and such implicit familiarity may contribute more generally to confidence assessments of word knowledge in both semantic and episodic memory domains. Furthermore, this outcome suggests that word feature priming in the form of partial phonological activation may occur to some extent for all words during a retrieval attempt, and even for ones that are judged to be unknown.     

Evidence for a difference in syntactic knowledge between skilled and less skilled adult readers

In two experiments, we investigated the relationship between reading ability and linguistic knowledge in adults. The results from Experiment 1 showed that good comprehenders performed more accurately than average comprehenders in a syntactic-judgment task that required them to decide whether pairs of words served the same grammatical function in sentences. By contrast, the reader groups performed similarly when required to make semantic judgments about whether pairs of words were related in meaning. In Experiment 2, individuals were classified according to comprehension level and reading speed. Good comprehenders again performed more accurately than average comprehenders in the syntactic task but not the semantic task. We argued that differences in form-class knowledge could be associated with corresponding differences in syntacticprocessing efficiency, and thus with variation in reading-comprehension skill generally.     

Strategy use in the reading span test: An analysis of eye movements and reported encoding strategies

Strategy use in the traditional reading span test was examined by recording participants’ eye movements during the task (Experiment 1) and by interviewing participants about their strategy use (Experiment 2). In Experiment 1, no differences between individuals with a low, medium, and high span were observed in how they distributed processing time between task elements. In all three groups, fixation times on words up to the to-be-remembered (TBR) word became shorter and the time spent on the TBR longer as memory load in the task increased. The results of Experiment 2, however, show that span groups differ in the use of memory encoding strategies: individuals with a low span use mainly rehearsal, whereas individuals with a high span use almost exclusively semantic elaboration. The results indicate that the use of elaborative strategies may enhance span performance but that not all individuals are necessarily able to use such strategies efficiently.     

Naming digits in a semantic blocking paradigm

It is widely agreed that word numerals are processed similar to other words, and, thus, they can be named without semantic mediation. However, there is no consensus about Arabic digits. Although digits seem to have a preferential link to magnitude representation, there is some evidence indicating a possible asemantic route to access phonological information. In the present study, we used a semantic blocking paradigm to explore this question. In Experiment 1, participants were asked to name digits and pictures or numeral words and name of objects in a semantic blocked context and in a mixed context. For both types of numerical notation we found facilitation in the blocked condition relative to the mixed condition. In Experiment 2, participants named two-digit numbers in a blocked condition (short numerical distance) or in a mixed condition (large numerical distance). Again, facilitation was found for the blocked condition relative to the mixed condition. This pattern of results seems to indicate that Arabic digits, like number words, might be named through an asemantic route.     

Experimental Studies in Ocular Behavior: I. The Dodge Mirror-Recorder for Photographing Eye-Movements

Two experiments are reported concerning the effects of semantic encoding operations on the subsequent usefulness of interitem semantic relations in recall. These experiments employ the Mathews paradigm in which Ss first make judgments about the semantic relatedness of words presented in triplets and subsequently have their memory for the words tested. These experiments examine the effects of variations in interitem associative strength (Experiment 1), and task instructions and triplet order (Experiment 2). The results are discussed in terms of the general effects of the semantic judgment task on the encoding of task-relevant and task-irrelevant semantic attributes of words.     

Naming digits in a semantic blocking paradigm

It is widely agreed that word numerals are processed similar to other words, and, thus, they can be named without semantic mediation. However, there is no consensus about Arabic digits. Although digits seem to have a preferential link to magnitude representation, there is some evidence indicating a possible asemantic route to access phonological information. In the present study, we used a semantic blocking paradigm to explore this question. In Experiment 1, participants were asked to name digits and pictures or numeral words and name of objects in a semantic blocked context and in a mixed context. For both types of numerical notation we found facilitation in the blocked condition relative to the mixed condition. In Experiment 2, participants named two-digit numbers in a blocked condition (short numerical distance) or in a mixed condition (large numerical distance). Again, facilitation was found for the blocked condition relative to the mixed condition. This pattern of results seems to indicate that Arabic digits, like number words, might be named through an asemantic route.     

Lexical coherence in short-term memory: Strategic reconstruction or “semantic glue”?

This study explores the foundation of lexical/semantic phoneme binding effects in verbal short-term memory (STM). The immediate serial recall of pure lists of words and nonwords was compared with the recall of mixed lists that had either a predictable, alternating structure (e.g., wnwnwn) or an unpredictable structure (i.e., the serial positions of the words/nonwords could not be known in advance). The study provides evidence for two separate mechanisms by which long-term linguistic knowledge contributes to STM. First, there was evidence for automatic lexical/semantic binding effects that were independent of knowledge of lexical status. The nonwords in both types of mixed list damaged word recall and encouraged the phonological elements of words to migrate. In both alternating and unpredictable mixed lists, the phonemes of words were more likely than the phonemes of nonwords to be recalled together as a coherent item, suggesting that lexical/semantic knowledge encourages the phonological elements of words to emerge together in immediate serial recall, even when lexical status is unknown. Secondly, there was evidence for “strategic redintegration”, which was dependent on prior knowledge of the lexical status of the items in mixed lists. When participants recalled items that they knew to be words in advance, they were able to use this knowledge to constrain their responses so that they were more likely to be lexically appropriate. These findings motivate modifications to current theories of the interaction between linguistic knowledge and verbal short-term memory.     

Accent modulates access to word meaning: Evidence for a speaker-model account of spoken word recognition

Speech carries accent information relevant to determining the speaker’s linguistic and social background. A series of web-based experiments demonstrate that accent cues can modulate access to word meaning. In Experiments 1–3, British participants were more likely to retrieve the American dominant meaning (e.g., hat meaning of “bonnet”) in a word association task if they heard the words in an American than a British accent. In addition, results from a speeded semantic decision task (Experiment 4) and sentence comprehension task (Experiment 5) confirm that accent modulates on-line meaning retrieval such that comprehension of ambiguous words is easier when the relevant word meaning is dominant in the speaker’s dialect. Critically, neutral-accent speech items, created by morphing British- and American-accented recordings, were interpreted in a similar way to accented words when embedded in a context of accented words (Experiment 2). This finding indicates that listeners do not use accent to guide meaning retrieval on a word-by-word basis; instead they use accent information to determine the dialectic identity of a speaker and then use their experience of that dialect to guide meaning access for all words spoken by that person. These results motivate a speaker-model account of spoken word recognition in which comprehenders determine key characteristics of their interlocutor and use this knowledge to guide word meaning access.     

Further evidence of the intricacy of memory span

Memory span was measured for lists of verbal items constructed such that the items in the first half of the list were of one category and those of the second half were of another. In Experiment 1, the lists consisted of digits and words (e.g., 2, 8, 7, horse, cow, sheep or horse, cow, sheep, 2, 8, 7); in Experiment 2, they consisted of words from the same semantic domain and words from different semantic domains; in Experiments 3 and 4, they consisted of words that rhymed and words that did not rhyme. A category-order effect occurred in each experiment: Span was larger when the digits, same-domain words, or rhyming words occurred in the first half of the list than when they occurred in the second half. These findings suggest that memory span is more complex than is generally assumed.     

The acquisition of morphological knowledge investigated through artificial language learning

Affix knowledge plays an important role in visual word recognition, but little is known about how it is acquired. The authors present a new method of investigating the acquisition of affixes in which participants are trained on novel affixes presented in novel word contexts (e.g., sleepnept). Experiment 1 investigated the role of semantic information on affix acquisition by comparing a form-learning condition with a condition in which participants also received definitions for each novel word. Experiment 2 investigated the role of long-term consolidation on affix acquisition by comparing knowledge of learned affixes two days and nearly two months after training. Results demonstrated that episodic knowledge of affixes can be acquired shortly after a single training session using either form or semantic learning, but suggested that the development of lexicalized representations of affixes requires the provision of semantic information during learning as well as a substantial period of offline consolidation.     

Negative priming from masked words: retrospective prime clarification of center-surround inhibition?

Masked repetition and semantic priming effects were examined in 2 experiments. In Experiment 1, a masked-prime lexical decision task followed a phase of detection, semantic, or repetition judgments about masked words. In Experiment 2 participants made speeded pronunciations to target words after they tried to identify masked primes, and the proportion of semantically and identically related prime-target pairs was varied. Center-surround theory CT. H. Carr & D. Dagenbach, 1990; D. Dagenbach, T. H. Carr, & A. Wilhelmsen, 1989) predicts positive repetition priming but negative semantic priming when people attempt, but fail, to extract the meanings of masked words. A retrospective prime-clarification account, in contrast, predicts that semantic and repetition priming effects will vary (being positive or negative) as a function of expectations about the prime-target relation. The data support a retrospective prime-clarification account, which, unlike center-surround theory, correctly predicted negative repetition priming effects.     

Context effects of pictures and words in naming objects, reading words, and generating simple phrases

In five language production experiments it was examined which aspects of words are activated in memory by context pictures and words. Context pictures yielded Stroop-like and semantic effects on response times when participants generated gender-marked noun phrases in response to written words (Experiment 1A). However, pictures yielded no such effects when participants simply read aloud the noun phrases (Experiment 2). Moreover, pictures yielded a gender congruency effect in generating gender-marked noun phrases in response to the written words (Experiments 3A and 3B). These findings suggest that context pictures activate lemmas (i.e., representations of syntactic properties), which leads to effects only when lemmas are needed to generate a response (i.e., in Experiments 1A, 3A, and 3B, but not in Experiment 2). Context words yielded Stroop-like and semantic effects in picture naming (Experiment 1B). Moreover, words yielded Stroop-like but no semantic effects in reading nouns (Experiment 4) and in generating noun phrases (Experiment 5). These findings suggest that context words activate the lemmas and forms of their names, which leads to semantic effects when lemmas are required for responding (Experiment 1B) but not when only the forms are required (Experiment 4). WEAVER++ simulations of the results are presented.     

Multisensory synesthetic interactions in the speeded classification of visual size

In the present study, we attempted to demonstrate a synesthetic relationship between auditory frequency and visual size. In Experiment 1, participants performed a speeded visual size discrimination task in which they had to judge whether a variable-sized disk was bigger or smaller than a standard reference disk. A task-irrelevant sound that was either synesthetically congruent with the relative size of the disk (e.g., a low-frequency sound presented with a bigger disk) or synesthetically incongruent with it (e.g., a low-frequency sound presented with a smaller disk) was sometimes presented together with the variable disk. Reaction times were shorter in the synesthetically congruent condition than in the incongruent condition. Verbal labeling and semantic mediation interpretations of this interaction were explored in Experiment 2, in which high- and low-frequency sounds were presented in separate blocks of trials, and in Experiment 3, in which the tones were replaced by the spoken words "high" and "low." Response priming/bias explanations were ruled out in Experiment 4, in which a synesthetic congruency effect was still reported even when participants made same-versus-different discrimination responses regarding the relative sizes of the two disks. Taken together, these results provide the first empirical demonstration that the relative frequency of an irrelevant sound can influence the speed with which participants judge the size of visual stimuli when the sound varies on a trial-by-trial basis along a synesthetically compatible dimension. The possible cognitive bases for this synesthetic association are also discussed.