儿童理解监控的即时加工过程

理解监控在口语和阅读信息的交流中起关键作用。即时加工研究为揭示儿童理解监控发展特点及内在机制提供了新途径。本文结合已有口语理解监控和阅读理解监控成果,对儿童理解监控的特点及其可能的影响因素进行了全面综述。未来研究应在儿童理解监控的时间进程、口语理解监控及理论模型等方面进一步深化,积极开展脑机制研究,并从视听跨通道整合角度探索儿童理解监控过程的发展。     

语义关联性对重复知盲效应的影响：来自汉语成语的证据

重复知盲是在快速系列视觉呈现任务中对第二个重复刺激的加工缺陷。以汉语中反义字和成语为实验材料,采用全部报告任务,探讨刺激的语义关联性对重复知盲的影响。实验1以汉语单字为材料,采用单因素三水平（目标刺激之间的语义关系：无关、相同、相反）被试内设计,结果是重复字产生重复知盲效应,反义字产生语义启动效应。实验2以成语为材料,采用2（目标刺激之间的语义关系：相同、无关）×2（位置：前位置、后位置）设计,结果是语义关联性消解了重复知盲效应。结果表明：（1）反义字不产生重复知盲效应。（2）语义关联性消解成语中重复字的重复知盲效应。（3）实验结果支持竞争假设。     

心理模拟在语言理解中的作用

心理模拟在语言理解中的作用逐渐受到人们重视。相关理论包括知觉符号系统理论、语言的神经理论和语言与情境模拟理论。行为研究发现感知觉运动信息与语言理解存在交互作用,而脑机制研究显示感知觉运动脑区参与语言理解。目前的研究对于心理模拟参与语言理解的机制仍缺乏细致探讨,导致结果存在矛盾之处。对隐喻语言里心理模拟作用的探讨也需加强。此外,心理模拟系统如何与语言学信息交互作用的相关假设也需要完善。     

Interplay between acoustic/phonetic and semantic processes during spoken sentence comprehension: an ERP study

When listening to speech in everyday-life situations, our cognitive system must often cope with signal instabilities such as sudden breaks, mispronunciations, interfering noises or reverberations potentially causing disruptions at the acoustic/phonetic interface and preventing efficient lexical access and semantic integration. The physiological mechanisms allowing listeners to react instantaneously to such fast and unexpected perturbations in order to maintain intelligibility of the delivered message are still partly unknown. The present electroencephalography (EEG) study aimed at investigating the cortical responses to real-time detection of a sudden acoustic/phonetic change occurring in connected speech and how these mechanisms interfere with semantic integration. Participants listened to sentences in which final words could contain signal reversals along the temporal dimension (time-reversed speech) of varying durations and could have either a low- or high-cloze probability within sentence context. Results revealed that early detection of the acoustic/phonetic change elicited a fronto-central negativity shortly after the onset of the manipulation that matched the spatio-temporal features of the Mismatch Negativity (MMN) recorded in the same participants during an oddball paradigm. Time reversal also affected late event-related potentials (ERPs) reflecting semantic expectancies (N400) differently when words were predictable or not from the sentence context. These findings are discussed in the context of brain signatures to transient acoustic/phonetic variations in speech. They contribute to a better understanding of natural speech comprehension as they show that acoustic/phonetic information and semantic knowledge strongly interact under adverse conditions.     

BOLD response to motion verbs in left posterior middle temporal gyrus during story comprehension

A primary focus within neuroimaging research on language comprehension is on the distribution of semantic knowledge in the brain. Studies have shown that the left posterior middle temporal gyrus (LPMT), a region just anterior to area MT/V5, is important for the processing of complex action knowledge. It has also been found that motion verbs cause activation in LPMT. In this experiment we investigated whether this effect could be replicated in a setting resembling real life language comprehension, i.e. without any overt behavioral task during passive listening to a story. During fMRI participants listened to a recording of the story “The Ugly Duckling”. We incorporated a nuisance elimination regression approach for factoring out known nuisance variables both in terms of physiological noise, sound intensity, linguistic variables and emotional content. Compared to the remaining text, clauses containing motion verbs were accompanied by a robust activation of LPMT with no other significant effects, consistent with the hypothesis that this brain region is important for processing motion knowledge, even during naturalistic language comprehension conditions.     

Are depictive gestures like pictures? commonalities and differences in semantic processing

Conversation is multi-modal, involving both talk and gesture. Does understanding depictive gestures engage processes similar to those recruited in the comprehension of drawings or photographs? Event-related brain potentials (ERPs) were recorded from neurotypical adults as they viewed spontaneously produced depictive gestures preceded by congruent and incongruent contexts. Gestures were presented either dynamically in short, soundless video-clips, or statically as freeze frames extracted from gesture videos. In a separate ERP experiment, the same participants viewed related or unrelated pairs of photographs depicting common real-world objects. Both object photos and gesture stimuli elicited less negative ERPs from 400 to 600 ms post-stimulus when preceded by matching versus mismatching contexts (dN450). Object photos and static gesture stills also elicited less negative ERPs between 300 and 400 ms post-stimulus (dN300). Findings demonstrate commonalities between the conceptual integration processes underlying the interpretation of iconic gestures and other types of image-based representations of the visual world.     

A sensitive period for language in the visual cortex: distinct patterns of plasticity in congenitally versus late blind adults

Recent evidence suggests that blindness enables visual circuits to contribute to language processing. We examined whether this dramatic functional plasticity has a sensitive period. BOLD fMRI signal was measured in congenitally blind, late blind (blindness onset 9-years-old or later) and sighted participants while they performed a sentence comprehension task. In a control condition, participants listened to backwards speech and made match/non-match to sample judgments. In both congenitally and late blind participants BOLD signal increased in bilateral foveal-pericalcarine cortex during response preparation, irrespective of whether the stimulus was a sentence or backwards speech. However, left occipital areas (pericalcarine, extrastriate, fusiform and lateral) responded more to sentences than backwards speech only in congenitally blind people. We conclude that age of blindness onset constrains the non-visual functions of occipital cortex: while plasticity is present in both congenitally and late blind individuals, recruitment of visual circuits for language depends on blindness during childhood.