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In a semantic priming paradigm, the effects of different levels of processing on the N400 were assessed by chang ing the task demands. In the lexical decision task, subjects had to discriminate between words and nonwords, and in the physical task, subjects had to discriminate between uppercase and lowercase letters. The proportion of related versus unrelated word pairs differed between conditions. A lexicality test on reaction times demonstrated that the physical task was performed nonlexically. Moreover, a semantic priming reaction time effect was obtained only in the lexical decision task. The level of processing clearly affected the event-related potentials. An N400 priming effect was only observed in the lexical decision task. In contrast, in the physical task a P300 effect was observed for either related or unrelated targets, depending on their frequency of occurrence. Taken together, the results indicate that an N400 priming effect is only evoked when the task performance induces the semantic aspects of words to become part of an episodic trace of the stimulus event.Descriptors: Levels of processing, Semantic priming, N400, P300In this study, we investigated the influence of task demands on the N400 semantic priming effect. In particular, we focused on the impact on the N400 of different levels of processing of lexical stimuli. In this report, we first discuss the relevant semantic prim ing effects and the mechanisms responsible for these priming effects then we introduce the levels of processing framework within which semantic priming effects were investigated.One of the most consistent findings in the psycholinguistic literature is that words are processed faster and more accurately when they are preceded by a semantically related or associated word than by an unrelated word (e.g., Meyer & Schvaneveldt, 1971; see Neely, 1991, for a review). More recently, it has been demonstrated that semantic priming effects can also be recorded with the use of the event-related brain potential (ERP) method. Hillyard (1980, 1984) identified an ERP component, the N400, a negative peak with a mean latency of 400 ms and a centroparietal distribution, that is larger in amplitude for words that are semantically incongruent with a preceding sen tence context. Subsequent research has shown that the N400 is tied more to semantic expectancy than to anomaly (e.g., Kutas, Lindamood, & Hillyard, 1984).

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Abstract■ Language switching in bilingual speakers requires attentional control to select the appropriate language, for example, in picture naming. Previous language-switch studies used the color of pictures to indicate the required language thereby confounding endogenous and exogenous control. To investigate endogenous language control, our language cues preceded picture stimuli by 750 msec. Cue-locked event-related potentials (ERPs) were measured while Dutch-English bilingual speakers overtly named pictures. The response language on consecutive trials could be the same (repeat trials) or different (switch trials). Naming latencies were longer on switch than on repeat trials, independent of the response language. Cue-locked ERPs showed an early posterior negativity for switch compared to repeat trials for L2 but not for L1, and a late anterior negativity for switch compared to repeat trials for both languages. The early switch-repeat effect might reflect disengaging from the nontarget native language, whereas the late switch-repeat effect reflects engaging in the target language. Implications for models of bilingual word production are discussed. ■

Abstract& Monitoring refers to a process of quality control designed to optimize behavioral outcome. Monitoring for action errors manifests itself in an error-related negativity in event-related potential (ERP) studies and in an increase in activity of the anterior cingulate in functional magnetic resonance imaging studies. Here we report evidence for a monitoring process in perception, in particular, language perception, manifesting itself in a late positivity in the ERP. This late positivity, the P600, appears to be triggered by a conflict between two interpretations, one delivered by the standard syntactic algorithm and one by a plausibility heuristic which combines individual word meanings in the most plausible way. To resolve this conflict, we propose that the brain reanalyzes the memory trace of the perceptual input to check for the possibility of a processing error. Thus, as in Experiment 1, when the reader is presented with semantically anomalous sentences such as, ''The fox that shot the poacher. . .,'' full syntactic analysis indicates a semantic anomaly, whereas the word-based heuristic leads to a plausible interpretation, that of a poacher shooting a fox. That readers actually pursue such a word-based analysis is indicated by the fact that the usual ERP index of semantic anomaly, the socalled N400 effect, was absent in this case. A P600 effect appeared instead. In Experiment 2, we found that even when the word-based heuristic indicated that only part of the sentence was plausible (e.g

In the language domain, most studies of error monitoring have been devoted to language production. However, in language perception, errors are made as well and we are able to detect them. According to the monitoring theory of language perception, a strong conflict between what is expected and what is observed triggers reanalysis to check for possible perceptual errors, a process reflected by the P600. This is at variance with the dominant view that the P600 reflects syntactic reanalysis or repair, after syntactic violations or ambiguity. In the present study, the prediction of the monitoring theory of language perception was tested, that only a strong conflict between expectancies triggers reanalysis to check for possible perceptual errors, reflected by the P600. Therefore, we manipulated plausibility, and hypothesized that when a critical noun is mildly implausible in the given sentence (e.g., "The eye consisting of among other things a pupil, iris, and eyebrow ..."), a mild conflict arises between the expected and unexpected event; integration difficulties arise due to the unexpectedness but they are resolved successfully, thereby eliciting an N400 effect. When the noun is deeply implausible however (e.g., "The eye consisting of among other things a pupil, iris, and sticker ..."), a strong conflict arises; integration fails and reanalysis is triggered, eliciting a P600 effect. Our hypothesis was confirmed; only when the conflict between the expected and unexpected event is strong enough, reanalysis is triggered.

According to embodied theories, the symbols used by language are meaningful because they are grounded in perception, action, and emotion. In contrast, according to abstract symbol theories, meaning arises from the syntactic combination of abstract, amodal symbols. If language is grounded in internal bodily states, then one would predict that emotion affects language. Consistent with this, advocates of embodied theories propose a strong link between emotion and language [Havas, D., Glenberg, A. M., & Rinck, M. Emotion simulation during language comprehension. Psychonomic Bulletin & Review, 14, 436-441, 2007; Niedenthal, P. M. Embodying emotion. Science, 316, 1002-1005, 2007]. The goal of this study was to test abstract symbol vs. embodied views of language by investigating whether mood affects semantic processing. To this aim, we induced different emotional states (happy vs. sad) by presenting film clips that displayed fragments from a happy movie or a sad movie. The clips were presented before and during blocks of sentences in which the cloze probability of mid-sentence critical words varied (high vs. low). Participants read sentences while ERPs were recorded. The mood induction procedure was successful: Participants watching the happy film clips scored higher on a mood scale than those watching the sad clips. For N400, mood by cloze probability interactions were obtained. The N400 cloze effect was strongly reduced in the sad mood compared with the happy mood condition. Furthermore, a difference in late positivity was only present for the sad mood condition. The mood by semantic processing interaction observed for N400 supports embodied theories of meaning and challenges abstract symbol theories that assume that processing of word meaning reflects a modular process.