Event-related potential and reaction time evidence for inhibition between alternative meanings of ambiguous words

We investigated the effects of two primes that converged onto the same semantic target representation (e.g., LION-STRIPES-TIGER) or diverged onto different semantic target representations (e.g., KIDNEY-PIANO-ORGAN). Balota and Paul (1996) showed that the RT effects of two related primes in naming and lexical decision are additive, both for unambiguous and ambiguous words. Only in a relatedness judgment task ambiguous words showed underadditivity, whereas unambiguous words again showed additivity. This underadditivity was interpreted to reflect inhibition of alternative meanings of ambiguous words. In this article we tested whether inhibition occurs for N400, assumed to index postlexical integration. In lexical decision, we found additive N400 and RT effects for unambiguous and for ambiguous words. In a relatedness judgment task we observed differences between measures: (1) for unambiguous words overadditivity for N400 vs. additivity for RT; (2) although, for ambiguous words underadditivity occurred for N400 and RT, the effects were different. For RT, the alternative meaning was only less available, whereas for N400 the alternative meaning appeared completely unavailable. Our results have implications for our understanding of inhibitory processes in the processing of ambiguous words and for the functional significance of N400.     

Friendly drug-dealers and terrifying puppies: Affective primacy can attenuate the N400 effect in emotional discourse contexts

Words that are semantically congruous with their preceding discourse context are easier to process than words that are semantically incongruous with their context. This facilitation of semantic processing is reflected by an attenuation of the N400 event-related potential (ERP). We asked whether this was true of emotional words in emotional contexts where discourse congruity was conferred through emotional valence. ERPs were measured as 24 participants read two-sentence scenarios with critical words that varied by emotion (pleasant, unpleasant, or neutral) and congruity (congruous or incongruous). Semantic predictability, constraint, and plausibility were comparable across the neutral and emotional scenarios. As expected, the N400 was smaller to neutral words that were semantically congruous (vs. incongruous) with their neutral discourse context. No such N400 congruity effect was observed on emotional words following emotional discourse contexts. Rather, the amplitude of the N400 was small to all emotional words (pleasant and unpleasant), regardless of whether their emotional valence was congruous with the valence of their emotional discourse context. However, consistent with previous studies, the emotional words produced a larger late positivity than did the neutral words. These data suggest that comprehenders bypassed deep semantic processing of valence-incongruous emotional words within the N400 time window, moving rapidly on to evaluate the words’ motivational significance.     

An ERP study of sensory mismatch expressions in Japanese

Combinations of different sensory words produce mismatch expressions like smooth color and red touch in contrast to normal expressions like red color and smooth touch. Concerning these sensory mismatch expressions, results of three experiments are reported. Experiment 1 revealed that (i) mismatch expressions were less comprehensible than normal expressions, and that (ii) there were two patterns among mismatch expressions: the high-comprehensible mismatch expression (HighCME, e.g., smooth color) and the low-comprehensible mismatch expression (LowCME, e.g., red touch). Experiment 2 revealed that the mismatch expressions produced a significantly greater N400 amplitude than the normal expressions. Experiment 3 implied that the difference between High/LowCME was reflected in a later latency band or in a topographical difference of N400, although the statistical significance was marginal. It is argued that the processes to integrate linguistic elements (e.g., combining adjectives and nouns) are not homogeneous.     

Discourse-based emotional consistency modulates early and middle components of event-related potentials

In this study, participants read stories describing emotional episodes with either a positive or negative valence (Experiment 1). Following each story, participants were exposed to short sentences referring to the protagonist, and the event-related potential (ERP) for each sentence's last word was recorded. Some sentences described the protagonist's emotion, either consistent or inconsistent with the story; others were neutral; and others involved a semantically anomalous word. Inconsistent emotions were found to elicit larger N100/P200 and N400 than consistent emotions. However, when participants were exposed to the same critical sentences in a control experiment (Experiment 2) in which the stories had been removed, emotional consistency effects disappeared in all ERP components, demonstrating that these effects were discourse-level phenomena. By contrast, the ordinary N400 effect for locally anomalous words in the sentence was obtained both with and without story context. In conclusion, reading stories describing events with emotional significance determines strong and very early anticipations of an emotional word.     

Social class differences in N400 indicate differences in spontaneous trait inference

An emerging literature indicates that dispositional bias in causal attribution of social behavior is weaker for people with working-class (vs. middle-class) backgrounds. However, it is unknown whether this difference is also present in spontaneous forms of trait inference. In the current work, American undergraduates were asked to merely memorize many pairings of a target face and a trait-implying behavior. In a subsequent lexical judgment task, after each face was presented as a fixation, either an implied trait or its antonym was given as a target. As expected, participants with college-educated parents (middle class) showed a strong N400 event-related potential component to the antonym (vs. the implied trait), suggesting spontaneous trait inference during the memorization phase. In contrast, those with high-school-educated parents (working class) showed no such effect. It is important to note that the N400 spontaneous trait inference effect was associated with perceived significance of dispositions in accounting for social behaviors.     

音乐对情感词加工的情感/意义双启动效应

本研究在前人研究的基础上进一步探讨音乐对情感词的启动机制。采用内隐情感启动范式,运用脑电技术考察多种情感类型的音乐片段对情感意义一致或不一致的词加工的启动影响。行为实验结果显示,音乐对情感词产生启动效应。脑电实验的结果发现,音乐对情感词的启动效应表现为早晚两个子成分的N400效应,首先是音乐直接引发的情绪产生第一个启动,表现为早成分的N400;其次是音乐通过联想引发的情感语义而产生第二个启动,表现为晚成分的N400。据此可以认为,音乐对情感词的启动是双启动模式。     

Performance of neurotics and stables on the standard progressive matrices

The significance of the role of Neuroticism (N) as an important determiner of learning and performance was investigated. The relation of N to performance on intelligence tests was analyzed and it was predicted that as item difficulty increased high N subjects would perform progressively worse and low N subjects would perform better. This type of analysis was shown to demonstrate the Yerkes-Dodson phenomenon better than a single total test score. In the present investigation, 400 subjects were selected for a 2 × 2 design consisting of two personality groups (neurotics vs. stables) and two sexes. Subjects were administered the Standard Progressive Matrices, an intelligence test having five progressively more difficult stages. The findings were that neurotics performed better on the simpler set, but as items became more difficult the stables performed significantly better than neurotics. A correlational analysis also showed a positive relation between N and the first set of items, and a negative relation between N and the other four sets.     

The N400 effect in children: relationships with comprehension, vocabulary and decoding

Using event-related potentials (ERPs), we investigated the N400 (an ERP component that occurs in response to meaningful stimuli) in children aged 8-10 years old and examined relationships between the N400 and individual differences in listening comprehension, word recognition and non-word decoding. Moreover, we tested the claim that the N400 effect provides a valuable indicator of behavioural vocabulary knowledge. Eighteen children were presented with picture-word pairs that were either ‘congruent’ (the picture depicted the spoken word) or ‘incongruent’ (they were unrelated). Three peaks were observed in the ERP waveform triggered to the onset of the picture-word stimuli: an N100 in fronto-central channels, an N200 in central-parietal channels and an N400 in frontal, central and parietal channels. In contrast to the N100 peak, the N200 and N400 peaks were sensitive to semantic incongruency with greater peak amplitudes for incongruent than congruent conditions. The incongruency effects for each peak correlated positively with listening comprehension but when the peak amplitudes were averaged across congruent/incongruent conditions they correlated positively with non-word decoding. These findings provide neurophysiological support for the position that sensitivity to semantic context (reflected in the N400 effect) is crucial for comprehension whereas phonological decoding skill relates to more general processing differences reflected in the ERP waveform. There were no correlations between ERP and behavioural measures of expressive or receptive vocabulary knowledge for the same items, suggesting that the N400 effect may not be a reliable estimate of vocabulary knowledge in children aged 8-10 years.     

The effects of processing requirements on neurophysiological responses to spoken sentences

Ten English speaking subjects listened to sentences that varied in sentential constraint (i.e., the degree to which the context of a sentence predicts the final word of that sentence) and event-related potentials (ERPs) were recorded during the presentation of the final word of each sentence. In the Control condition subjects merely listened to the sentences. In the Orthographic processing condition subjects merely listened to the sentences. In the Orthographic processing condition subjects decided, following each sentence, whether a given letter had been present in the final word of the preceding sentence. In the Phonological processing condition the subjects judged whether a given speech sound was contained in the terminal word. In the Semantic processing condition subjects determined whether the final word was a member of a given semantic category. A previous finding in the visual modality that the N400 component was larger in amplitude for low constraint sentence terminations than for high was extended to the auditory modality. It was also found that the amplitude of a N200-like response was similarly responsive to contextual constraint. The hypothesis that N400 amplitude would vary significantly with the depth of processing of the terminal word was not supported by the data. The "N200" recorded in this language processing context showed the classic frontocentral distribution of the N200. The N400 to spoken sentences had a central/centroparietal distribution similar to the N400 in visual modality experiments. It is suggested that the N400 obtained in these sentence contexts reflects an automatic semantic processing of words that occurs even when semantic analysis is not required to complete a given task. The cooccurrence and topographical dissimilarity of the "N200" and N400 suggest that the N400 may not be a delayed or a generic N200.     

Equivalence relations do exist before they are tested: Confirmatory evidence revealed by EEG measurements

We examined equivalence-based N400 effects by comparing EEG data from participants with different experiences with equivalence testing. Before a priming task used in EEG measurement, Group 1 was given only matching-to-sample training trials whereas Group 2 was exposed to matching-to-sample training and equivalence probe trials. We asked whether exposure to the reinforcement contingency was sufficient to bring about an N400 outcome that might indicate potentially emergent equivalence relations or if such a response depended on experience with equivalence tests. Results showed robust N400 in both groups. Experience with equivalence tests did not further increase the N400 effects. Our findings add confirmatory evidence that equivalence relations may originate via the reinforcement contingency alone. Furthermore, complementary EEG data collected from priming tasks involving words from natural language showed functional overlap between laboratory-defined equivalence and natural word-based N400 effects.     

Semantic memory and verbal working memory correlates of N400 to subordinate homographs

N400 is an event-related brain potential that indexes operations in semantic memory conceptual space, whether elicited by language or some other representation (e.g., drawings). Language models typically propose three stages: lexical access or orthographic- and phonological-level analysis; lexical selection or word-level meaning and associate activation; and lexical integration, sentence- and discourse-level operations. The exact stage that N400 reflects is unknown, although opinion favors lexical integration over lexical selection. Surprisingly, little research has assessed relationships between neuropsychological measures of semantic memory fund of information or verbal working memory capacity and N400. Subjects performed a homograph disambiguation comprehension task with minimal working memory load. Short sentences read: The noun was adjective/verb. The nouns were either homographs or unambiguous. The adjective/verb was disambiguating for the homograph, and congruent or incongruent for the unambiguous noun. The primary noun of interest was the subordinate homograph. Comprehension of the subordinate meaning should correlate with semantic memory stores, reflecting greater knowledge. If N400 primarily reflects lexical access operations, it should also correlate with measures of semantic knowledge. If N400 reflects lexical integration, it should correlate with measures of working memory capacity. Comprehension errors were associated with semantic memory stores, but not working memory capacity. N400 was related to working memory capacity, but not semantic knowledge, suggesting that N400 primarily reflects late-stage working memory operations. N400 to subordinate disambiguating words was larger with greater working memory capacity, and thus may index the absolute capacity of working memory rather than difficulty in contextual integration.     

Finding the Locus of Semantic Satiation: An Electrophysiological Attempt

The present study examined the effect of massed repetition of an initial category name upon the subsequent semantic categorization of a target word by means of an electrophysiological measure of semantic processing: the N400. Results showed the classic N400 effect, whereby evoked potentials were more negative for targets that were not members of the repeated category than for member targets. Moreover, repetition of the category name led to an increased and sustained positivity. The N400 effect was not modified, however, by repetition. Hence, insomuch as the N400 reflects meaning integration processes, these results do not support the hypothesis that massed repetition exerts its influence at the level of meaning integration.     

N200, N250r, and N400 event-related brain potentials reveal three loci of repetition priming for familiar names

The authors assessed immediate repetition effects on event-related potentials (ERPs) while participants performed familiarity decisions for written personal names. For immediately repeated familiar names, the authors observed 3 distinct ERP modulations. At 180-220 ms, a posterior N200 effect occurred for names preceded by same-font primes only. In addition, an increased left temporal negativity (N250r, 220-300 ms) and a reduced central-parietal negativity (N400, 300-400 ms) were seen both for same-font and different-font repetitions. In a 2nd experiment, when names were preceded by either their corresponding face or the face of a different celebrity, only the N400 effect was preserved. These findings suggest that the N200, N250r, and N400 effects reflect facilitated processing at font-specific featural, lexical, and semantic levels of processing, respectively.     

Brain responses to semantic incongruity in bilinguals

Event-related potentials were examined in the first and second languages of bilinguals, and in monolinguals. Stimuli were anomalous sentences presented one word at a time on a CRT monitor. The principal dependent measure was the N400 component, and an accompanying frontal negativity, which provided an estimate of the amount of time the nervous system takes to determine the semantic incongruity of a given word. The results indicate that N400 latency is slightly, but significantly, delayed in bilinguals, with monolinguals having the shortest mean N400 latency, the first language of bilinguals next, and the second language of bilinguals longest. The frontal negativity varied in amplitude somewhat independently of the parietal N400. The amplitude of the frontal negativity was sometimes reduced in the second language, tending to be smaller in those subjects who used their second language the least. Neither N400 nor the frontal negativity varied as a function of age of acquisition of the second language. The results are discussed with reference to the relative automaticity of language in bilinguals, and the sensitivity of N400 to variations in the automaticity of language processing.     

FN400和N400是相同的ERP成分：来自图形材料的证据

本研究通过比较记忆编码阶段语义启动引起的N400效应和提取阶段熟悉性引起的FN400效应的地形图考察图形材料诱发的N400和FN400是否是相同的ERP成分。实验结果发现,语义启动引起的N400效应和熟悉性引起的FN400效应的地形图没有显著差异。这说明图形材料诱发的FN400和N400是相同的ERP成分,两者都反映了语义加工。本研究为FN400效应反映了语义启动而不是熟悉性的观点提供了新的实验证据。     

Influences of semantic and syntactic context on open- and closed-class words

Event-related potentials (ERPs) were recorded as subjects read semantically meaningful, syntactically legal but nonsensical and random word strings. The constraints imposed by formal sentence structure alone did not reduce the amplitude of the N400 component elicited by open-class words, whereas semantic constraints did. Semantic constraints also eliminated the word-frequency effect of a larger N400 for low-frequency words. Responses to closed-class words exhibited reduced N400 amplitudes in syntactic and congruent sentences, indicating that formal sentence structure placed greater restrictions on closed-class words than it did on open-class words. However, unlike the open-class results, the impact of sentence context on closed-class words was stable across word positions, suggesting that these syntactic constraints were applied only locally. A second ERP component, distinct from the N400, was elicited primarily by congruent closed-class words.     

Is "Blank" a suitable neutral prime for event-related potential experiments?

We report an experiment that evaluates whether BLANK or an unrelated prime is a more suitable baseline for assessing priming for an ERP study. Sixteen subjects performed a lexical decision task with a 1 s prime-target stimulus onset asynchrony. Increased amplitude for the N400 was observed for targets in the unrelated prime condition whereas targets in the BLANK prime condition evoked activity that was more like that in the related prime condition. Theoretically, we conclude that the N400 reflects semantic integration. Pragmatically, we conclude that the BLANK prime is a better neutral prime but that unrelated primes yield stronger N400 effects.     

Contextual modulation of N400 amplitude to lexically ambiguous words

Though much is known about the N400 component, an event-related EEG potential that is sensitive to semantic manipulations, it is unclear whether modulations of N400 amplitude reflect automatic processing, controlled processing, or both. We examined this issue using a semantic judgment task that manipulated local and global contextual cues. Word triplets (prime-noun-target, e.g., finance-bank-money) were sequentially presented on a computer screen (500 ms duration, 1000 ms stimulus onset asynchrony), in which the second word was a homograph. The first word (prime) created a neutral-, dominant-meaning- or subordinate-meaning-biased "global context," and the third word (target) created a dominant- or subordinate-biased "local context" that was either congruent or incongruent with the "global context" established by the first prime word. Participants were instructed to read all three words but to decide only whether the second and third words were semantically related. Event-related potentials (ERPs), specifically the N400, were recorded to the third terminal word. N400 amplitudes evoked by dominant meaning-related third words incongruent with the globally biased subordinate context (e.g., river-bridge-money) were significantly more negative than dominant endings in neutral contexts (e.g., taxi-bank-money), but not different from unrelated filler triplets. In addition, there was some indication that left hemisphere, temporal-parietal electrode sites were associated with greater N400 negativity for dominant targets in conflicting subordinate global contexts than homologous right hemisphere electrode sites, the latter of which showed significant activation to subordinate meanings in cooperating contexts. Thus, N400 amplitude was more affected by global than local context suggesting that controlled processes may take priority over automatic processes in modulating N400 amplitude, especially for left hemisphere electrode sites.     

Electrophysiological manifestations of typicality judgment

Ten male subjects participated in an event-related potential study of typicality judgment of words that were of either high or low frequency of usage. The amplitude of a negative wave with an average peak latency of 490 msec (N400) correlated with the goodness-of-fit of a word to a particular category independent of frequency, with poor examples of the category evoking a significantly more negative waveform. The relative insensitivity of the N400 to word frequency suggests that the N400 reflects some postlexical evaluation rather than lexical access.     

Event-related potential sensitivity to acoustic and semantic properties of terminal words in sentences.

This experiment was concerned with the effects of phonologically correct masking on the electrophysiological responses to terminal words of spoken sentences differing in contextual constraint. Two event-related potential (ERP) components, the N400 and N200, were recorded to the terminal words of high and low constraint sentences in four conditions. In the Control condition, subjects (Ss) simply attended to the sentences with no explicit task instructions. In the Semantic condition, Ss were required to listen to the stimuli in order to make semantic judgements about the terminal word of each sentence. The Control+Masking condition was identical to the Control condition except for the simultaneous presentation of a masking stimulus. The Semantic+Masking condition had Ss listening to sentences in the presence of masking with the task of making semantic judgements about the terminal word of each sentence. ERPs were recorded from Fz, Cz, Pz, T3, and T4 in 10 subjects. Amplitudes of both the N200 and the N400 were sensitive to contextual constraint with larger responses elicited by the terminal words of low constraint sentences. In addition to demonstrating the co-occurrence of the N200 and N400, this experiment highlighted a functional separation between the two components. Masking had no statistically significant effect on N200 latency but N400 latency was delayed in the masked conditions relative to those in the unmasked conditions. It is proposed that the N200 and N400 are manifestations of two different processes; the N200 reflects the acoustic/phonological processing of the terminal word while the N400 reflects the cognitive/linguistic processing. The relationship between the N200 recorded in this experiment and the discrimination N200 is discussed.