Memory effects in syntactic ERP tasks

The study presented here investigated the role of memory in normal sentence processing by looking at ERP effects to normal sentences and sentences containing grammatical violations. Sentences where the critical word was in the middle of the sentence were compared to sentences where the critical word always occurred in sentence-final position. Grammaticality judgments were required at the end of the sentence. While the violations in both conditions result in the expected increase in the P600 component (reflecting the fact that the syntactic violation is being processed), the sentences with the sentence-medial critical word also result in a late frontal negativity effect. It is hypothesized that this effect is due to greater memory requirements that are needed to keep the violation in mind until a response can be made at the end of the sentence. The maintenance of the decision that a sentence is ungrammatical must be kept in memory longer for sentence-medial violations as opposed to when the violation occurs at the end of the sentence (immediately preceding the moment at which the judgment can be made).     

The maze task: Measuring forced incremental sentence processing time

The maze task is an online measure of sentence processing time that provides an alternative to the standard moving window version of self-paced reading. Rather than each word of the sentence being presented in succession, two words are presented at the same time, and the participant must choose which word is a grammatical continuation of the sentence. This procedure forces the reader into an incremental mode of processing in which each word must be fully integrated with the preceding context before the next word can be considered. Previous research with this technique has not considered whether it is sufficiently sensitive to syntactic complexity effects or to garden path effects. Four experiments are reported demonstrating that reliable differences in processing time for subject relatives and object relatives can be obtained, and that this technique generates garden path effects that correspond closely with the data from eyetracking experiments, but without the spillover effects that are sometimes obtained with eyetracking. It is also shown that the task is sensitive to word frequency effects, producing estimates well in excess of those found with eyetracking.     

句子阅读理解过程中句意的建构时间

一般语言学理论认为, 在句子阅读理解过程中, 句子意义建构是基于词汇语义整合的, 其反映在N400之上, 开始于词语呈现后约250 ms。然而, 近年关于语义P600效应的研究却提示句意建构可能存在多通道或方式, 读者甚至可能在N400反映的加工出现之前就已建立了初步句意。为探明在句子阅读理解过程中是否存在比N400反映的加工更早的句意建构, 以及如果存在这样的句意建构, 其是从何时开始的, 本研究开展了四个实验。实验1发现被试在句末双字词呈现200 ms后已将其联系到上文语义表征而建立了句意, 提示句意建构开始于N400反映的加工出现之前。实验2与3进一步发现, 读者开始建立句意的时间约在句末词呈现了150 ms之时。实验4排除了实验1~3效应的其他一些可能解释, 提升了实验1~3结果的可靠性。总体上, 本研究提示：在句子阅读理解过程中, 读者在句末双字词呈现了约150 ms之时就已建立了句意; 可能存在比N400反映的加工更早的句意建构。     

Reading between the lines: Event-related brain potentials during natural sentence processing

Event-related potentials (ERPs) were recorded from subjects as they silently read 160 different seven-word sentences, presented one word at a time. Each sentence was in itself a natural, meaningful phrase. Substantial intersubject variability was observed in the ERP waveshapes following the words. More than half of the subjects generated P3 components to word stimuli, but those who did showed similar responses to repeated control presentations of a single word. In addition, it was found that all but the first word in the sentence elicited an ERP with a significant left-greater-than-right asymmetry in the late positivity over temporo-parietal regions. The ERPs to the last words were associated with more late positivity than those to the preceding words. One quarter of the sentences, at random, ended with a word printed in a typeface that was different from that of the preceding words. This infrequent change in typeface elicited a complex ERP having three consistent late positive components.     

The use of rhythm in attending to speech

Three experiments examined attentional allocation during speech processing to determine whether listeners capitalize on the rhythmic nature of speech and attend more closely to stressed than to unstressed syllables. Ss performed a phoneme monitoring task in which the target phoneme occurred on a syllable that was either predicted to be stressed or unstressed by the context preceding the target word. Stimuli were digitally edited to eliminate the local acoustic correlates of stress. A sentential context and a context composed of word lists, in which all the words had the same stress pattern, were used. In both cases, the results suggest that attention may be preferentially allocated to stressed syllables during speech processing. However, a normal sentence context may not provide strong predictive cues to lexical stress, limiting the use of the attentional focus.     

Phoneme-monitoring reaction time and preceding prosody: Effects of stop closure duration and of fundamental frequency

In an earlier study, it was shown that listeners can use prosodic cues that predict where sentence stress will fall; phoneme-monitoring RTs are faster when the preceding prosody indicates that the word bearing the target will be stressed. Two experiments which further investigate this effect are described. In the first, it is shown that the duration of the closure preceding the release of the target stop consonant burst does not affect the RT advantage for stressed words. In the second, it is shown that fundamental frequency variation is not a necessary component of the prosodic variation that produces the predicted-stress effect. It is argued that sentence processing involves a very flexible use of prosodic information.     

Prosodic structure and wh-questions

This study examines the influence of wh-gaps on the prosodic contour of spoken utterances. A previous study (Nagel, Shapiro, & Nawy, 1994) claimed that the phonological representation of a sentence containing a filler-gap dependency explicitly encodes the location of the syntactic gap. In support of this hypothesis, Nagel et al. presented evidence that the word immediately preceding a gap is lengthened and that there is a reliable increase in pitch excursion across the gap location. Our study challenges Nagel et al.'s claim. We argue that their materials confounded the presence/absence of a gap with other factors that are known to affect intonational phrasing independently. We show that, when these factors are separated, the evidence that syntactic gaps are explicitly encoded in the phonological representation of a sentence disappears.     

文本阅读中背景信息的加工过程：激活与整合

采用移动窗口技术和眼动技术探讨了文本阅读中当前信息跟背景信息的具体加工过程。被试为华南师范大学本科生92名。实验1使用移动窗口技术,计算机屏幕上每次只呈现一个句子,让被试自己按键逐句进行阅读,通过分析不同实验条件下探测词的再认反应时间和不同实验条件下目标句的阅读时间来探讨文本阅读中信息加工的具体过程。实验2使用眼动技术在一种更自然的情境中通过分析不同实验条件下眼动指标的差异来进一步探讨文本阅读中信息加工的具体过程。实验结果表明,文本阅读中背景信息的加工过程包括激活和整合两个阶段,这两个阶段相互独立但又紧密联系,激活是整合发生的前提,有整合必先发生激活,但激活发生后并不一定会发生整合;文本阅读过程中读者阅读时间的延长主要发生在整合阶段     

Memory connections between thematically similar episodes

Recent theories about the representation of thematic information in memory propose that two episodes that share a theme are connected together through a thematic structure. We investigated the use of such cross-episode connections in comprehension and memory in six experiments. Experiments 1 and 2 used a priming technique; it was found that verification time for a test sentence from one story was speeded by an immediately preceding test sentence from a thematically similar story but only when subjects were given instructions to rate the similarities of the stories. In the remaining experiments, a single test sentence was presented immediately after a story was read, with timing controlled by presenting the story one word at a time. Response time for a test sentence from a previously read story was facilitated if the immediately preceding story was thematically similar, but only if the previously read story was extensively prestudied. We conclude that, during reading of an episode, thematic information may be encoded so as to lead to activation of similar episodes and formation of connections in memory between episodes, but such encoding is not automatic and depends on subjects' strategies and task difficulty.     

句子理解中颜色信息的心理表征

采用混合实验设计、实时和事后的句子-图片匹配范式, 以隐含物体典型颜色和非典型颜色信息的句子为实验材料, 以被试对图片的反应时间和阅读时间为因变量指标, 通过不同时间间隔的设置以及不同的实验程序, 探讨了句子理解中静态和动态颜色信息心理表征的特点。结果表明：(1)在加工时间有限的情况下, 两个加工任务是否竞争相同的认知资源是造成句-图范式下匹配易化和不匹配易化的关键因素。(2)对于句子隐含的静态颜色信息, 大脑对典型颜色信息的心理表征具有即时性和局部性, 而对非典型颜色信息的心理表征还具有非局部性的特点。(3)对于句子隐含的动态颜色信息, 大脑不能对其进行即时的心理表征, 这种动态颜色信息的心理表征是在句子阅读晚期发生的。     

Syntactic context and lexical access

Recent studies demonstrating that multiple meanings of an ambiguous word are initially accessed even when only one reading is syntactically appropriate with the preceding context can be criticized on at least two grounds. First, many of the syntactic contexts used were not truly restrictive, and, secondly, subjects may not have had time to integrate the context before processing the ambiguous word. In the present study, subjects listened to a sentence ending in an ambiguous word and then made a lexical decision to a target related to either the appropriate or inappropriate reading. Contexts were completely restrictive, and a pause was introduced between the context and the ambiguous word. Multiple access still obtained, providing further support for the claim that lexical access is not guided by syntactic context.     

Understanding words in sentence contexts: the time course of ambiguity resolution

Spoken language comprehension requires rapid integration of information from multiple linguistic sources. In the present study we addressed the temporal aspects of this integration process by focusing on the time course of the selection of the appropriate meaning of lexical ambiguities ("bank") in sentence contexts. Successful selection of the contextually appropriate meaning of the ambiguous word is dependent upon the rapid binding of the contextual information in the sentence to the appropriate meaning of the ambiguity. We used the N400 to identify the time course of this binding process. The N400 was measured to target words that followed three types of context sentences. In the concordant context, the sentence biased the meaning of the sentence-final ambiguous word so that it was related to the target. In the discordant context, the sentence context biased the meaning so that it was not related to the target. In the unrelated control condition, the sentences ended in an unambiguous noun that was unrelated to the target. Half of the concordant sentences biased the dominant meaning, and the other half biased the subordinate meaning of the sentence-final ambiguous words. The ISI between onset of the target word and offset of the sentence-final word of the context sentence was 100 ms in one version of the experiment, and 1250 ms in the second version. We found that (i) the lexically dominant meaning is always partly activated, independent of context, (ii) initially both dominant and subordinate meaning are (partly) activated, which suggests that contextual and lexical factors both contribute to sentence interpretation without context completely overriding lexical information, and (iii) strong lexical influences remain present for a relatively long period of time.     

The generalizability of context effects on word recognition: A reconsideration of the roles of parafoveal priming and sentence context

In three experiments, subjects named target words preceded by congruous, incongruous, or neutral sentence contexts. There was no evidence that the recognition of the target word was affected by the semantic characteristics of a word presented immediately to the right of it. The nature of the preceding sentence context did affect target-naming speed. However, the magnitude of the context effect was considerably smaller in these experiments, in which nonterminal target words were used, than in previous experiments in which the target word was always the final word of the sentence, was highly predictable from the context, and was often semantically related to words in the sentence. The implications of these two findings for theories of reading and context effects are discussed.     

Interference and facilitation effects of primes upon verification processes

Priming effects on sentence verification were investigated. The semantic relation of the prime and the probe, and the interval between prime and probe presentation (SOA), were varied for both ambiguous and unambiguous sentences. Reaction time to decide that a sentence was true or false was longer if the preceding prime was a word that was unrelated to the probe than if the prime was the word “blank.” In contradiction of Posner and Snyder’s (1975) claim that conscious processes develop slowly, this result was found at SOAs as short as 250 msec. Verification performance was facilitated for both sentence types when the prime word was the first of the to-be-presented probe sentence, but the magnitude of the facilitation effects depended upon the truth value of the probe, the associative strength of the subject and predicate of the probe sentence, and upon SOA. These findings indicate that priming affects the processing of relations among concepts in semantic memory, as well as the encoding of the probe.     

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.     

The processing of rhythmic structures in music and prosody by children with developmental dyslexia and developmental language disorder

Rhythm perception seems to be crucial to language development. Many studies have shown that children with developmental dyslexia and developmental language disorder have difficulties in processing rhythmic structures. In this study, we investigated the relationships between prosody and musical processing in Italian children with typical and atypical development. The tasks aimed to reproduce linguistic prosodic structures through musical sequences, offering a direct comparison between the two domains without violating the specificities of each one. About 16 Typically Developing children, 16 children with a diagnosis of Developmental Dyslexia, and 16 with a diagnosis of developmental language disorder (age 10–13 years) participated in the experimental study. Three tasks were administered: an association task between a sentence and its humming version, a stress discrimination task (between couples of sounds reproducing the intonation of Italian trisyllabic words), and an association task between trisyllabic nonwords with different stress position and three‐notes musical sequences with different musical stress. Children with developmental language disorder perform significantly lower than Typically Developing children on the humming test. By contrast, children with developmental dyslexia are significantly slower than TD in associating nonwords with musical sequences. Accuracy and speed in the experimental tests correlate with metaphonological, language, and word reading scores. Theoretical and clinical implications are discussed within a multidimensional model of neurodevelopmental disorders including prosodic and rhythmic skills at word and sentence level.     

Effects of Case Marking and Word Order on Sentence Parsing in Finnish: An Eye Fixation Analysis

Effects of case marking and word order on syntactic parsing in Finnish were examined by registering readers' eye fixation patterns while they read single sentences for comprehension. Target nouns appearing towards the beginning of the sentence took one of three grammatical roles: subject, object, or adverbial. The subject phrase in the sentence-initial position is the canonical order in Finnish, but the two other word orders are less frequent. In one experimental condition, the grammatical role of the target noun was signalled by a case inflection attached to the preceding adjective modifier; in the second condition this was not the case. The results showed a facilitation effect in sentence parsing due to case marking. Similarly, there was an effect of word order, where the canonical SVO order was associated with greater processing ease than were non-canonical word orders. The two factors interacted so that there was no effect of case marking for the SVO order, but a significant case marking effect for the two marked word orders. The same pattern of results showed up as both immediate and delayed effects. The results speak against the notion of head licensing proposed by Abney (1989) and Prichett (1991).     

The interpretation of ambiguous trimorphemic words in sentence context

Many trimorphemic words are structurally and semantically ambiguous. For example, unlock-able can either be un-lockable (cannot be locked) or unlock-able (can be unlocked). Which interpretation is preferred and whether the preceding sentence context affects the initial interpretation is not clear from prior research. The present experiment embedded ambiguous trimorphemic words in sentence contexts, manipulated whether or not preceding context disambiguated the meaning, and examined the pattern of fixation durations on the ambiguous word and the remainder of the text. The results indicated that the unlock-able interpretation was preferred; moreover, preceding context did not exert a significant effect until the eyes had initially exited from the target word.     

Active memory processes in visual sentence comprehension: Clause effects and pronominal reference

Two experiments were conducted to investigate active memory processes during reading. Subjects read two-clause sentences one word at a time at a self-paced rate. Following each sentence a probe word was presented; subjects were to decide if this word occurred in the sentence they had just read. The first experiment examined clausal effects during reading. Reaction times to items from the final clause were shorter than those to items from a previous clause even when the same number of words intervened. The second experiment used the clause effect to address the issue of proniminal reference. Results indicated that a pronoun in the final clause activated the meaning of its antecedent, thus demonstrating that the method is sensitive to both surface and meaning codes in active memory.     

Semantic similarity, predictability, and models of sentence processing

The effects of word predictability and shared semantic similarity between a target word and other words that could have taken its place in a sentence on language comprehension are investigated using data from a reading time study, a sentence completion study, and linear mixed-effects regression modeling. We find that processing is facilitated if the different possible words that could occur in a given context are semantically similar to each other, meaning that processing is affected not only by the nature of the words that do occur, but also the relationships between the words that do occur and those that could have occurred. We discuss possible causes of the semantic similarity effect and point to possible limitations of using probability as a model of cognitive effort.