Prime Words Research Articles

The N400 event-related potential as a neural correlate of language proficiency

Event Abstract Back to Event The N400 event-related potential as a neural correlate of language proficiency Erin Corkett1* and Stephen Provost1 1 Southern Cross University, Psychology, School of Health and Human Sciences, Australia Aims: The N400 component of event-related potentials (ERPs) is a neural correlate of language processing. Despite there being a rich literature on the N400, little is known about its potential as a measure of language proficiency in an individuals’ ability to read, write, and speak. We examined whether there is a relationship between the N400 and language proficiency. Method: Participants completed three tasks: the National Adult Reading Task (NART), a sentence discrimination task, and a lexical decision task. Electroencephalography was recorded from 16 participants in the lexical decision task. An individual trial consisted of a fixation cross for 3000 ms, a prime word for 400 ms, a second fixation cross for 750 ms, a target word that was either congruent or incongruent with the prime word for 400 ms, and a third fixation cross for 500 ms. Results: A difference wave comparing ERPs to congruent and incongruent words was calculated over the time-window associated with N400 (350 to 500 ms). The size of this difference wave was correlated with scores on the NART, sentence discrimination task, and lexical decision task. Conclusions: The relation between psychophysiological and behavioural measures of linguistic ability are important as they help to inform both theories of such behaviour, and potential efforts to find effective means for the amelioration of deficient performance. The evidence described here provides the first such investigation in an adult higher education population. The results will be used in the development of teaching strategies designed to support the acquisition of high-level language skills. Keywords: language processing, N400, event-related potential, Linguistic proficiency Conference: 12th Annual Psychology Research Conference, 2015, Coffs Harbour, Australia, 25 Sep - 26 Sep, 2015. Presentation Type: Research Topic: Psychology Citation: Corkett E and Provost S (2015). The N400 event-related potential as a neural correlate of language proficiency. Front. Psychol. Conference Abstract: 12th Annual Psychology Research Conference, 2015. doi: 10.3389/conf.fpsyg.2015.66.00004 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Sep 2015; Published Online: 23 Sep 2015. * Correspondence: Ms. Erin Corkett, Southern Cross University, Psychology, School of Health and Human Sciences, Coffs Harbour, NSW, 2450, Australia, e.corkett.10@student.scu.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Erin Corkett Stephen Provost Google Erin Corkett Stephen Provost Google Scholar Erin Corkett Stephen Provost PubMed Erin Corkett Stephen Provost Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Emotional and cognitive processing in Parkinson's disease

Event Abstract Back to Event Emotional and cognitive processing in Parkinson's disease Nadeeka Dissanayaka1, 2*, Tiffany Au1, Anthony Angwin3, John O'Sullivan2, Gerard Byrne4, 5, Peter Silburn1, 2, Rodney Marsh4, 5, George Mellick2, 6 and David Copland1, 3 1 The University of Queensland Centre for Clinical Research and RBWH, UQ Centre for Clinical Research, Australia 2 Royal Brisbane & Women's Hospital, Neurology Research Centre, Australia 3 The University of Queensland Centre for Clinical Research and RBWH, School of Health & Rehabilitation Sciences, Australia 4 The University of Queensland Centre for Clinical Research and RBWH, School of Medicine, Australia 5 Royal Brisbane & Women's Hospital, Department of Psychiatry, Australia 6 Griffith University , Eskitis Institute for Cell & Molecular Therapies, Australia Background: Emotional dysfunction and cognitive impairment are frequent non-motor complications in Parkinson's disease (PD). Over 50% experience anxiety and depression, 25% experience mild cognitive impairment (MCI), and a further 25% experience dementia at end stage PD. However, mechanisms underpinning these neuropsychiatric disturbances in PD are poorly understood. This study aims to identify event related potentials (ERPs) associated with cognitive and affective processes in PD. Methods: Fifty three (53) PD patients completed a visual word affective priming task while ERPs were recorded. The task presented negative or neutral word pairs with a stimulus onset asynchrony of 250ms. Participants evaluated the valance of the second word (target word). Repeated measures ANOVAs were used to investigate the effects of Target Valence and Congruency on P3 and LPP ERP amplitudes. We also investigated the interactions between these factors and depression, anxiety and cognitive rating scale scores using covariance and subsequent partial correlations. Results: P3 and LPP amplitude deflections were larger for negative targets compared to neutral targets at Pz electrode (P3 F=6.82, p=0.01; for LPP F=5.88, p=0.01). Target valence X Congruency X Covariate interactions were observed for depression (P3 F=7.8, p<0.01; LPP F=4.30, p=0.04) and cognitive impairment (P3 F=10.3, p<0.01, LPP F=5.84, p=0.01). The P3 difference wave (incongruent - congruent) for neutral targets positively and independently correlated with depression (r=0.39, p=0.005) and cognitive impairment (r=0.33, p=0.02). Similarly, the LPP difference wave for neutral targets positively correlated with depression when adjusted for cognitive impairment and anxiety (r=0.35, p=0.02). Conclusion: P3 and LPP allow discrimination of negative biases associated with stimulus processing. These results demonstrate that depression and cognitive impairment independently influence the processing of negative prime words in PD. Keywords: Cognition, Depression, Parkinson's disease, Event Related Potentials, LPP, P3, negative biases Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Emotional and Social Processes Citation: Dissanayaka N, Au T, Angwin A, O'Sullivan J, Byrne G, Silburn P, Marsh R, Mellick G and Copland D (2015). Emotional and cognitive processing in Parkinson's disease. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00166 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Ms. Nadeeka Dissanayaka, The University of Queensland Centre for Clinical Research and RBWH, UQ Centre for Clinical Research, Brisbane, Australia, n.dissanayaka@uq.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nadeeka Dissanayaka Tiffany Au Anthony Angwin John O'Sullivan Gerard Byrne Peter Silburn Rodney Marsh George Mellick David Copland Google Nadeeka Dissanayaka Tiffany Au Anthony Angwin John O'Sullivan Gerard Byrne Peter Silburn Rodney Marsh George Mellick David Copland Google Scholar Nadeeka Dissanayaka Tiffany Au Anthony Angwin John O'Sullivan Gerard Byrne Peter Silburn Rodney Marsh George Mellick David Copland PubMed Nadeeka Dissanayaka Tiffany Au Anthony Angwin John O'Sullivan Gerard Byrne Peter Silburn Rodney Marsh George Mellick David Copland Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Late bilinguals see a scan in scannerAND in scandal: dissecting formal overlap from morphological priming in the processing of derived words

Masked priming research with late (non-native) bilinguals has reported facilitation effects following morphologically derived prime words (scanner – scan). However, unlike for native speakers, there are suggestions that purely orthographic prime-target overlap (scandal – scan) also produces priming in non-native visual word recognition. Our study directly compares orthographically related and derived prime-target pairs. While native readers showed morphological but not formal overlap priming, the two prime types yielded the same magnitudes of facilitation for non-natives. We argue that early word recognition processes in a non-native language are more influenced by surface-form properties than in one's native language.

Repetition priming of words and nonwords in Alzheimer's disease and normal aging.

This study examines the magnitude and direction of nonword and word lexical decision repetition priming effects in Alzheimer's disease (AD) and normal aging, focusing specifically on the negative priming effect sometimes observed with repeated nonwords. Probable AD patients (30), elderly normal controls (34), and young normal controls (49) participated in a repetition priming experiment using low-frequency words and word-like nonwords with a letter-level orthographic orienting task at study followed by a lexical decision test phase. Although participants' reaction times (RTs) were longer in AD compared with elderly normal, and elderly normal compared with young normal, the repetition priming effect and the degree to which the repetition priming effect was reversed for nonwords compared to words was unaffected by AD or normal aging. AD patients, like young and elderly normal participants, are able to modify (in the case of words) and create (in the case of nonwords) long-term memory traces for lexical stimuli, based on a single orthographic processing trial. The nonword repetition results are discussed from the perspective of new vocabulary learning commencing with a provisional lexical memory trace created after orthographic encoding of a novel word-like letter string.

Priming word order by thematic roles: No evidence for an additional involvement of phrase structure

Three experiments are reported that studied the priming of word order in German. Experiment 1 demonstrated priming of the order of case-marked verb arguments. However, order of noun phrases and order of thematic roles were confounded. In Experiment 2, we therefore aimed at disentangling the impact of these two possible factors. By using primes that differed from targets in phrase structure but were parallel with regard to the order of thematic roles, we nevertheless found priming demonstrating the critical impact of thematic roles. Experiment 3 replicated the priming effects from Experiments 1 and 2 within participants and revealed no evidence for a modulation of priming by phrase structure. Consequently, our findings suggest that word order priming crucially depends on the structural outline of thematic roles rather than on the linearization of phrases.

Dense neighborhoods and mechanisms of learning: evidence from children with phonological delay.

There is a noted advantage of dense neighborhoods in language acquisition, but the learning mechanism that drives the effect is not well understood. Two hypotheses--long-term auditory word priming and phonological working memory--have been advanced in the literature as viable accounts. These were evaluated in two treatment studies enrolling twelve children with phonological delay. Study 1 exposed children to dense neighbors versus non-neighbors before training sound production in evaluation of the priming hypothesis. Study 2 exposed children to the same stimuli after training sound production as a test of the phonological working memory hypothesis. Results showed that neighbors led to greater phonological generalization than non-neighbors, but only when presented prior to training production. There was little generalization and no differential effect of exposure to neighbors or non-neighbors after training production. Priming was thus supported as a possible mechanism of learning behind the dense neighborhood advantage in phonological acquisition.

Language proficiency and morpho-orthographic segmentation.

One key finding in support of the hypothesis that written words are automatically parsed into component morphemes independently of the true morphological structure of the stimuli, so-called morpho-orthographic segmentation, is that suffixed nonword primes facilitate the visual recognition of a stem target (rapidifier-RAPIDE) whereas non-suffixed primes (rapiduit-RAPIDE) do not. However, Morris, Porter, Grainger, and Holcomb (Language & Cognitive Processes, 26(4-6), 558-599, 2011)reported equivalent priming from suffixed and non-suffixed nonword primes, hence questioning the morphological nature of prior findings. Here we provide a further investigation of masked priming with morphologically complex nonword primes with an aim to isolate factors that modulate the size of these priming effects. We conducted a masked primed lexical decision experiment in French, in which the same target (TRISTE) was preceded by a suffixed word (tristesse), a suffixed nonword (tristerie), a non-suffixed nonword (tristald), or an unrelated prime word (direction). Participants were split into two groups, based on their language proficiency. The results show that in the high proficiency group, comparable magnitudes of priming were obtained in all three related prime conditions (including the non-suffixed condition) relative to unrelated primes, whereas in the low proficiency group, priming was significantly reduced in the non-suffixed condition compared to the two suffixed conditions. These findings provide further evidence that individual differences in language proficiency can modulate the impact of morphological factors during reading, and an explanation for the discrepant findings in prior research.

Maximal voluntary force strengthened by the enhancement of motor system state through barely visible priming words with reward.

The topic of unconscious influences on behaviour has long been explored as a means of understanding human performance and the neurobiological correlates of intention, motivation, and action. However, what is relatively unknown is whether subconsciously delivered priming stimuli, with or without rewards, can affect individuals’ maximum level of force produced with their best effort. We demonstrated using transcranial magnetic stimulation that barely visible priming of an action concept, when combined with a reward in the form of a consciously visible positive stimulus, could alter the state of the motor system. In accordance with this neurophysiological alteration, the prime-plus-reward stimuli significantly increased the hand-grip force level of maximum voluntary contraction with little conscious awareness. This is the first objective evidence that the barely conscious presence of a behavioral goal can influence the state of the motor system and arouse latent ability for human force exertion.

How Words Transcend and Pictures Immerse

Drawing from construal level theory, we test the hypothesis that words promote thinking of events in terms of their abstract and central features (i.e., high-level construal), whereas pictures promote thinking in terms of more concrete and idiosyncratic features (i.e., low-level construal). In Experiments 1a and 1b, we found that verbal (vs. pictorial) presentation of objects led to broader, more inclusive categorization of those objects. In Experiment 2, we found that word (vs. picture) priming led to greater global (vs. local) processing of subsequent perceptual information. Finally, in Experiments 3 and 4, we tested the opposite direction of causality. Thinking about high-level “why” versus relatively low-level “how” (Experiment 3) and thinking about high-level categories versus relatively low-level exemplars (Experiment 4) led to more verbal versus pictorial thought. These findings provide converging evidence that medium (word, picture) is associated with level of construal.

Task instructions modulate the attentional mode affecting the auditory MMN and the semantic N400.

Event-related potentials (ERPs) have been proven to be a useful tool to complement clinical assessment and to detect residual cognitive functions in patients with disorders of consciousness. These ERPs are often recorded using passive or unspecific instructions. Patient data obtained this way are then compared to data from healthy participants, which are usually recorded using active instructions. The present study investigates the effect of attentive modulations and particularly the effect of active vs. passive instruction on the ERP components mismatch negativity (MMN) and N400. A sample of 18 healthy participants listened to three auditory paradigms: an oddball, a word priming, and a sentence paradigm. Each paradigm was presented three times with different instructions: ignoring auditory stimuli, passive listening, and focused attention on the auditory stimuli. After each task, the participants indicated their subjective effort. The N400 decreased from the focused task to the passive task, and was extinct in the ignore task. The MMN exhibited higher amplitudes in the focused and passive task compared to the ignore task. The data indicate an effect of attention on the supratemporal component of the MMN. Subjective effort was equally high in the passive and focused tasks but reduced in the ignore task. We conclude that passive listening during EEG recording is stressful and attenuates ERPs, which renders the interpretation of the results obtained in such conditions difficult.

The role of literal meaning in figurative language comprehension: evidence from masked priming ERP.

The role of literal meaning during the construction of meaning that goes beyond pure literal composition was investigated by combining cross-modal masked priming and ERPs. This experimental design was chosen to compare two conflicting theoretical positions on this topic. The indirect access account claims that literal aspects are processed first, and additional meaning components are computed only if no satisfactory interpretation is reached. In contrast, the direct access approach argues that figurative aspects can be accessed immediately. We presented metaphors (These lawyers are hyenas, Experiment 1a and 1b) and producer-for-product metonymies (The boy read Böll, Experiment 2a and 2b) with and without a prime word that was semantically relevant to the literal meaning of the target word (furry and talented, respectively). In the presentation without priming, metaphors revealed a biphasic N400-Late Positivity pattern, while metonymies showed an N400 only. We interpret the findings within a two-phase language architecture where contextual expectations guide initial access (N400) and precede pragmatic adjustment resulting in reconceptualization (Late Positivity). With masked priming, the N400-difference was reduced for metaphors and vanished for metonymies. This speaks against the direct access view that predicts a facilitating effect for the literal condition only and hence would predict the N400-difference to increase. The results are more consistent with indirect access accounts that argue for facilitation effects for both conditions and consequently for consistent or even smaller N400-amplitude differences. This combined masked priming ERP paradigm therefore yields new insights into the role of literal meaning in the online composition of figurative language.

Effects of priming goal pursuit on implicit sequence learning.

Implicit learning, the type of learning that occurs without intent to learn or awareness of what has been learned, has been thought to be insensitive to the effects of priming, but recent studies suggest this is not the case. One study found that learning in the serial reaction time (SRT) task was improved by nonconscious goal pursuit, primed via a word search task (Eitam et al. in Psychol Sci 19:261-267, 2008). In two studies, we used the goal priming word search task from Eitam et al., but with a different version of the SRT, the alternating serial reaction time task (ASRT). Unlike the SRT, which often results in explicit knowledge and assesses sequence learning at one point in time, the ASRT has been shown to be implicit through sensitive measures of judgment, and it enables sequence learning to be measured continuously. In both studies, we found that implicit learning was superior in the groups that were primed for goal achievement compared to control groups, but the effect was transient. We discuss possible reasons for the observed time course of the positive effects of goal priming, as well as some future areas of investigation to better understand the mechanisms that underlie this effect, which could lead to methods to prolong the positive effects.

On the effect of subliminal priming on subjective perception of images: a machine learning approach.

The research presented in this article investigates the influence of subliminal prime words on peoples' judgment about images, through electroencephalograms (EEGs). In this cross domain priming paradigm, the participants are asked to rate how much they like the stimulus images, on a 7-point Likert scale, after being subliminally exposed to masked lexical prime words, with EEG recorded simultaneously. Statistical analysis tools are used to analyze the effect of priming on behavior, and machine learning techniques to infer the primes from EEGs. The experiment reveals strong effects of subliminal priming on the participants' explicit rating of images. The subjective judgment affected by the priming makes visible change in event-related potentials (ERPs); results show larger ERP amplitude for the negative primes compared with positive and neutral primes. In addition, Support Vector Machine (SVM) based classifiers are proposed to infer the prime types from the average ERPs, which yields a classification rate of 70%.

Pathways to meaning: Written and spoken word priming in children with ASD versus typically developing peers

Visual supports are widely utilized with children on the autism spectrum, however, the effect of visual versus auditory modality on language comprehension has not been directly investigated. To address this issue, we utilized a semantic priming paradigm in two experiments with 18 children with ASD and no language impairment and 14 children with typical development. In the first, cross-modal experiment with a spoken word prime, no priming effect was identified. In the second, uni-modal written word prime experiment, a three-way interaction was identified. Subsequent analysis revealed that priming occurred only in the younger participants with ASD. These results are discussed in terms of the cross- and uni-modal demands of the two experiments and in light of lexical processing of spoken and written words within a developmental framework.

Test–retest reliability of N400 event-related brain potential measures in a word-pair semantic priming paradigm in patients with schizophrenia

The N400 event-related brain potential (ERP), a negative voltage deflection occurring approximately 400ms after onset of any meaningful stimulus, is reduced in amplitude when the stimulus is preceded by related context. Previous work has found this N400 semantic priming effect to be decreased in schizophrenia, suggesting impairment in using meaningful context to activate related concepts in semantic memory. Thus, N400 amplitude may be a useful biomarker of abnormal semantic processing and its response to treatment in schizophrenia. To help assess the validity of N400 amplitude as a longitudinal measure in schizophrenia, we evaluated its test–retest reliability. ERPs were recorded in sixteen schizophrenia patients who viewed prime words, each followed at 300- or 750-ms stimulus-onset asynchrony (SOA) by a target that was either a related or unrelated word, or nonword. Participants' task was to indicate whether or not the target was a real word. They were retested on the same procedure one week later. Test–retest reliability was assessed by calculating Pearson's r and intraclass correlation coefficients (ICCs) across timepoints for N400 amplitudes for related and unrelated targets, at each SOA. Consistent with previous results, there were no significant differences between patients' N400 amplitudes for related and unrelated targets, at any SOA/timepoint combination. Pearson's r and ICCs for N400 amplitudes at Fz across timepoints were significant for both target types at each SOA (ranges: r 0.52–0.64, ICC 0.52–0.63; all p<.04). The results suggest potential utility of N400 amplitude as a longitudinal neurophysiological biomarker of semantic processing abnormalities in schizophrenia.

Treack or trit: Adaptation to genuine and arbitrary foreign accents by monolingual and bilingual listeners

Two cross-modal priming experiments examined two questions about word recognition in foreign-accented speech: Does accent adaptation occur only for genuine accents markers, and does adaptation depend on language experience? We compared recognition of words spoken with canonical, genuinely-accented and arbitrarily-accented vowels. In Experiment 1, an Italian speaker pronounced vowels in English prime words canonically, or by lengthening /ɪ/ as in a genuine Italian accent (*/tri:k/ for trick), or by arbitrarily shortening /i:/ (*/trɪt/ for treat). Lexical-decision times to subsequent visual target words showed different priming effects in three listener groups. Monolingual native English listeners recognized variants with lengthened but not shortened vowels. Bilingual nonnative Italian-English listeners, who could not reliably distinguish vowel length, recognized both variants. Bilingual nonnative Dutch-English listeners also recognized both variants. In Experiment 2, bilingual Dutch-English listeners recognized Dutch words with genuinely- and arbitrarily-accented vowels (spoken by a native Italian with lengthened and shortened vowels respectively), but recognized words with canonical vowels more easily than words with accented vowels. These results suggest that adaptation to genuine accent markers arises for monolingual and bilingual listeners alike and can occur in native and nonnative languages, but that bilinguals can adapt to arbitrary accent markers better than monolinguals.

How to meet the neighbors: Modality effects on phonological generalization

Long-term auditory priming of words from dense neighborhoods has been posited as a learning mechanism that affects change in the phonological structure of children's lexical representations. An apparent confound associated with the modality of priming responsible for structural change has been introduced in the literature, which challenges this proposal. Thus, our purpose was to evaluate prime modality in the treatment of children with phonological delay. Nine children were assigned to auditory–visual, auditory, or visual priming of words from dense neighborhoods prior to the treatment of production as the independent variable. The dependent variable was phonological generalization. Results showed that auditory priming (with or without visual input) promoted greater generalization on an order of magnitude of 3:1. Findings support the theoretical significance of auditory priming for phonological learning and demonstrate the applied utility of priming in clinical treatment.

Cardiovascular change during encoding predicts the nonconscious mere exposure effect.

These studies examined memory encoding to determine whether the mere exposure effect could be categorized as a form of conceptual or perceptual implicit priming and, if it was not conceptual or perceptual, whether cardiovascular psychophysiology could reveal its nature. Experiment 1 examined the effects of study phase level of processing on recognition, the mere exposure effect, and word identification implicit priming. Deep relative to shallow processing improved recognition but did not influence the mere exposure effect for nonwords or word identification implicit priming for words. Experiments 2 and 3 examined the effect of study-test changes in font and orientation, respectively, on the mere exposure effect and word identification implicit priming. Different study-test font and orientation reduced word identification implicit priming but had no influence on the mere exposure effect. Experiments 4 and 5 developed and used, respectively, a cardiovascular psychophysiological implicit priming paradigm to examine whether stimulus-specific cardiovascular reactivity at study predicted the mere exposure effect at test. Blood volume pulse change at study was significantly greater for nonwords that were later preferred than for nonwords that were not preferred at test. There was no difference in blood volume pulse change for words at study that were later either identified or not identified at test. Fluency effects, at encoding or retrieval, are an unlikely explanation for these behavioral and cardiovascular findings. The relation of blood volume pulse to affect suggests that an affective process that is not conceptual or perceptual contributes to the mere exposure effect.

An ERP investigation of dichotic repetition priming with temporally overlapping stimuli.

In the present study, we used event-related potentials (ERPs) to examine the effects of prime-target repetition using a dichotic priming paradigm. Participants monitored a stream of target words in the right, attended ear for occasional animal names, and ERPs were recorded to nonanimal words that were either unrelated to or a repetition of prime words presented to the left ear. The prime words were spoken in a different voice and had a lower intensity than did the target words, and the prime word onset occurred 50 ms before target word onset. Repetition-priming effects were observed in the ERPs starting around 150 ms post-target-onset and continued to influence processing for the duration of the target stimuli. These priming effects provide further evidence in favor of parallel processing of overlapping dichotic stimuli, at least up to the level of some form of sublexical phonological representation, a likely locus for the integration of the two sources of information.

The effects of visual half-field priming on the categorization of familiar intransitive gestures, tool use pantomimes, and meaningless hand movements.

Although the control of meaningful gestures is one of the most left-lateralized functions, the relative contribution of the two hemispheres to their processing is still debated. We tested the effects of primes appearing in the left or right visual field in the form of pictures (Experiment 1), and words (Experiment 2) on categorization of movies showing intransitive (“communicative”) gestures, tool use (transitive) pantomimes, and meaningless movements. Fifteen participants (eight women) watched 36 movies (12 from each category) primed for 150 ms with either a congruent or incongruent stimulus followed by a 50-ms mask. On congruent trials, a picture or word was directly related to the presented gesture, including nonsense pictures or non-words for meaningless actions. On incongruent trials, a picture or word belonged to a different category. In Experiment 1, intransitive gestures were categorized significantly faster than the other two types of hand movements. Moreover, whereas the categorization of transitive gestures was significantly facilitated by congruent pictures on the right, the effect was weaker for intransitive, and reversed for meaningless movements. In Experiment 2, intransitive gestures were again categorized significantly faster, but transitive significantly slower than the other two gesture categories. Yet, there was now a significant facilitation of intransitive, and inhibition of transitive gesture categorization following congruent prime words in the right visual field, and significantly faster categorization of intransitive gestures following incongruent words in the left visual field. These outcomes lend support to the complexity account of differences in left-hemisphere representations of meaningful gestures reported in the neuropsychological, behavioral, and neuroimaging literature. Nevertheless, they also indicate that the representations of intransitive gestures show some differential, and sometimes counterintuitive sensitivity to right hemisphere processing.