文盲与非文盲汉字字形和语音加工的脑机制

利用功能性磁共振成像(fMRI)技术探讨文盲和非文盲汉字字形和语音加工脑机制的差异。实验1使用汉字字形和图形比较了中国人文盲和非文盲字形加工过程脑机制的左侧差异。实验2使用汉字语音和纯音比较了文盲和非文盲语音加工过程脑机制的双侧差异。结果表明文盲与非文盲汉字字形和语音加工脑机制不同,且非文盲的脑活动强。     

Neuro-cognitive aspects of “OM” sound/syllable perception: A functional neuroimaging study

The sound “OM” is believed to bring mental peace and calm. The cortical activation associated with listening to sound “OM” in contrast to similar non-meaningful sound (TOM) and listening to a meaningful Hindi word (AAM) has been investigated using functional magnetic resonance imaging (MRI). The behaviour interleaved gradient technique was employed in order to avoid interference of scanner noise. The results reveal that listening to “OM” sound in contrast to the meaningful Hindi word condition activates areas of bilateral cerebellum, left middle frontal gyrus (dorsolateral middle frontal/BA 9), right precuneus (BA 5) and right supramarginal gyrus (SMG). Listening to “OM” sound in contrast to “non-meaningful” sound condition leads to cortical activation in bilateral middle frontal (BA9), right middle temporal (BA37), right angular gyrus (BA 40), right SMG and right superior middle frontal gyrus (BA 8). The conjunction analysis reveals that the common neural regions activated in listening to “OM” sound during both conditions are middle frontal (left dorsolateral middle frontal cortex) and right SMG. The results correspond to the fact that listening to “OM” sound recruits neural systems implicated in emotional empathy.     

Cultural differences in neural function associated with object processing

Behavioral research suggests that Westerners focus more on objects, whereas East Asians attend more to relationships and contexts. We evaluated the neural basis for these cultural differences in an event-related fMRI study. East Asian and American participants incidentally encoded pictures of (1) a target object alone, (2) a background scene with no discernable target object, and (3) a distinct target object against a meaningful background. Americans, relative to East Asians, activated more regions implicated in object processing, including bilateral middle temporal gyrus, left superior parietal/angular gyrus, and right superior temporal/supramarginal gyrus. In contrast to the cultural differences in object-processing areas, few differences emerged in background-processing regions. These results suggest that cultural experiences subtly direct neural activity, particularly for focal objects, at an early stage of scene encoding.     

Dissociation and association of the embodied representation of tool-use verbs and hand verbs: An fMRI study

Embodied semantic theories suppose that representation of word meaning and actual sensory-motor processing are implemented in overlapping systems. According to this view, association and dissociation of different word meaning should correspond to dissociation and association of the described sensory-motor processing. Previous studies demonstrate that although tool-use actions and hand actions have overlapping neural substrates, tool-use actions show greater activations in frontal–parietal–temporal regions that are responsible for motor control and tool knowledge processing. In the present study, we examined the association and the dissociation of the semantic representation of tool-use verbs and hand action verbs. Chinese verbs describing tool-use or hand actions without tools were included, and a passive reading task was employed. All verb conditions showed common activations in areas of left middle frontal gyrus, left inferior frontal gyrus (BA 44/45) and left inferior parietal lobule relative to rest, and all conditions showed significant effects in premotor areas within the mask of hand motion effects. Contrasts between tool-use verbs and hand verbs demonstrated that tool verbs elicited stronger activity in left superior parietal lobule, left middle frontal gyrus and left posterior middle temporal gyrus. Additionally, psychophysiological interaction analyses demonstrated that tool verbs indicated greater connectivity among these regions. These results suggest that the brain regions involved in tool-use action processing also play more important roles in tool-use verb processing and that similar systems may be responsible for word meaning representation and actual sensory-motor processing.     

The neural reality of syntactic transformations: evidence from functional magnetic resonance imaging

The functional anatomy of syntactic transformations, a major computational operation invoked in sentence processing, was identified through a functional magnetic resonance imaging investigation. A grammaticality judgment task was used, presented through a novel hidden-blocks design. Subjects listened to transformational and nontransformational sentences in which a host of other complexity generators (number of words, prepositions, embeddings, etc.) were kept constant. A series of analyses revealed that the neural processing of transformations is localizable, evoking a highly lateralized and localized activation in the left inferior frontal gyrus (Broca's region) and bilateral activation in the posterior superior temporal sulcus. The pattern of activation associated with transformational analysis was distinct from the one observed in neighboring regions, and anatomically separable from the effects of verb complexity, which yielded significant activation in the left posterior superior temporal sulcus. Taken together with neuropsychological evidence, these results uncover the neural reality of syntactic transformations.     

动词论元结构复杂性加工的认知神经机制

动词论元结构复杂性表现在论元数量、论元范畴选择模式、题元角色指派模式和映射方式四个方面。大部分实证研究表明, 更多的论元数量、选择性论元范畴、选择性题元角色指派以及非典型映射, 使动词论元结构加工的认知神经机制更复杂。多论元加工功能脑区主要涉及左侧额下回和外侧裂周后部; 选择性论元范畴加工功能脑区主要涉及左侧额下回、额叶中后部、颞上回和颞叶中后部; 选择性题元角色指派加工功能脑区主要涉及外侧裂周后部、左侧额叶中后部和额下回; 非典型映射加工功能脑区主要涉及左侧额下回、颞上回、颞中回和颞叶后部。左侧额下回可能涉及初始句法加工、动词次范畴确定、句法移位和非宾格动词语义加工, 左侧额叶中后部可能涉及初始句法加工和动词次范畴确定, 左侧颞上回和颞叶中后部可能涉及表层句法加工和表层论元句法-语义整合, 外侧裂周后部可能涉及论元语义表征。动词论元结构加工过程和动词词汇特征表明, 复杂性某些方面存在交互作用。动词论元结构复杂性与加工难易的对应关系、复杂性加工难度层级和交互作用的认知神经机制以及汉语动词论元结构复杂性加工认知神经机制等议题, 有待进一步探讨。     

Dissociating semantic and phonological maintenance using fMRI

Functional magnetic resonance imaging (fMRI) distinguished regions of neural activity associated with active maintenance of semantic and phonological information. Subjects saw a single word for 2 sec, and following a 10-sec delay, made a judgment about that word. In the semantic task, subjects focused on the meaning of the word and decided whether a second word was synonymous with it. In the phonological task, subjects repeated the word silently and decided whether it shared a vowel sound with a nonsense word. Analyses allowed for isolation of neural activity during the maintenance delay. Semantic maintenance elicited greater activity in bilateral inferior frontal gyrus and left middle temporal gyrus regions of interest (ROI). In contrast, there was greater activity for phonological maintenance in the left superior parietal ROI. These results show a frontal-temporal network involved in actively maintaining the meanings of words, and they indicate that semantic and phonological maintenance processes are dissociable within working memory.     

自闭症谱系障碍人群词义加工的脑激活模式：基于fMRI研究的元分析

本研究筛选了11项采用功能性磁共振成像技术探究言语自闭症人群词义加工的研究, 探讨了该人群与典型人群脑激活模式的差异是否具有跨研究的稳定性。结果表明, 差异的脑激活模式稳定存在, 且表现为主要涉及左额上回的典型脑区激活不足。该结果为言语ASD人群语言加工的神经机制提供了来自词义加工的跨研究激活证据, 在明确“减弱的额叶激活”这一稳定差异表现的基础上, 强调了针对不同语言加工任务开展元分析研究的必要性。     

The role of the ventral and dorsal pathways in reading Chinese characters and English words

Previous literature in alphabetic languages suggests that the occipital-temporal region (the ventral pathway) is specialized for automatic parallel word recognition, whereas the parietal region (the dorsal pathway) is specialized for serial letter-by-letter reading ( [Cohen et al., 2008] and [Ho et al., 2002] ). However, few studies have directly examined the role of the ventral and dorsal pathways in Chinese reading compared to English reading. To investigate this issue, we adopted the degraded word processing paradigm used by Cohen et al. (2008) and compared brain regions involved in the processing of degraded Chinese characters and English words during lexical decision, using functional magnetic resonance imaging (fMRI). The degraded characters/words were created by inserting blank spaces between radicals of Chinese characters or syllables of English polysyllabic words. Generally, the current study replicated the effects of Cohen et al. (2008), showing that in Chinese – like in alphabetic languages – character spacing modulates both ventral (bilateral cuneus, left middle occipital gyrus) and dorsal (left superior parietal lobule and middle frontal gyrus) pathways. In addition, the current study showed greater activation in bilateral cuneus and right lingual gyrus for Chinese versus English when comparing spaced to normal stimuli, suggesting that Chinese character recognition relies more on ventral visual-spatial processing than English word recognition. Interestingly, bilateral cuneus showed monotonic patterns in response to increasing spacing, while the rest of the regions of interest showed non-monotonic patterns, indicating different profiles for these regions in visual-spatial processing.     

汉语双字词在心理词典中的表征方式:来自fNIRS的证据

以汉语双字构成的真词与假词为实验材料,22名大学生为被试,采用功能性近红外脑成像技术(f NIRS)和事件相关设计,考察被试在完成词汇判断任务时的大脑激活模式,探索汉语双字词在心理词典中的表征方式。结果发现:(1)在完成真假词判断任务时,被试大脑左侧额叶和左侧颞叶均被激活;(2)与判断假词相比,被试在判断真词时显著地激活左额上回和左额中回。这一结果说明汉语双字词在心理词典中是混合表征的。     

The neural basis of autobiographical and semantic memory: new evidence from three PET studies

A novel, neuropsychologically informed paradigm (extended retrieval of events in response to a cue word) was used to investigate the neural basis of autobiographical and semantic memory. Contrasting retrieval of autobiographical memories with retrieval of semantic facts (ABM-SEM) in 24 subjects across three PET studies revealed bilateral involvement of the middle temporal gyrus (BA 21) and medial frontal cortex (BA 9/10). The opposite contrast, SEM-ABM, resulted in increased regional cerebral blood flow in left posterior temporal regions (BA 37) and left prefrontal cortex (BA 45/46). Laterality maps suggest that the bilateral pattern seen in our studies, but not often in other neuroimaging investigations, reflects the use of a task stressing retrieval of specific personal events. Further comparisons revealed that the activation in the right anterior temporal lobe during autobiographical recall was virtually identical to that seen during retrieval of information about famous people or events in contrast with retrieval of general semantic facts. These findings suggest that the retrieval of an autobiographical event requires participation from conceptual knowledge, and that this type of knowledge is bilaterally distributed in the temporal lobes.     

Modulation of brain activity during phonological familiarization

We measured brain activity in 12 adults for the repetition of auditorily presented words and nonwords, before and after repeated exposure to their phonological form. The nonword phoneme combinations were either of high (HF) or low (LF) phonotactic frequency. After familiarization, we observed, for both word and nonword conditions, decreased activation in the left posterior superior temporal gyrus, in the bilateral temporal pole and middle temporal gyri. At the same time, interaction analysis showed that the magnitude of decrease of activity in bilateral posterior temporal lobe was significantly smaller for LF nonwords, relative to words and HF nonwords. Decrease of activity in this area also correlated with the size of behavioral familiarization effects for LF nonwords. The results show that the posterior superior temporal gyrus plays a fundamental role during phonological learning. Its relationship to sublexical and lexical phonological processing as well as to phonological short-term memory is discussed.     

Neural responses to meaningless pseudosigns: evidence for sign-based phonetic processing in superior temporal cortex

To identify neural regions that automatically respond to linguistically structured, but meaningless manual gestures, 14 deaf native users of American Sign Language (ASL) and 14 hearing non-signers passively viewed pseudosigns (possible but non-existent ASL signs) and non-iconic ASL signs, in addition to a fixation baseline. For the contrast between pseudosigns and baseline, greater activation was observed in left posterior superior temporal sulcus (STS), but not in left inferior frontal gyrus (BA 44/45), for deaf signers compared to hearing non-signers, based on VOI analyses. We hypothesize that left STS is more engaged for signers because this region becomes tuned to human body movements that conform the phonological constraints of sign language. For deaf signers, the contrast between pseudosigns and known ASL signs revealed increased activation for pseudosigns in left posterior superior temporal gyrus (STG) and in left inferior frontal cortex, but no regions were found to be more engaged for known signs than for pseudosigns. This contrast revealed no significant differences in activation for hearing non-signers. We hypothesize that left STG is involved in recognizing linguistic phonetic units within a dynamic visual or auditory signal, such that less familiar structural combinations produce increased neural activation in this region for both pseudosigns and pseudowords.     

Cortical localisation of the visual and auditory word form areas: a reconsideration of the evidence

In this paper we examine the evidence for human brain areas dedicated to visual or auditory word form processing by comparing cortical activation for auditory word repetition, reading, picture naming, and environmental sound naming. Both reading and auditory word repetition activated left lateralised regions in the frontal operculum (Broca's area), posterior superior temporal gyrus (Wernicke's area), posterior inferior temporal cortex, and a region in the mid superior temporal sulcus relative to baseline conditions that controlled for sensory input and motor output processing. In addition, auditory word repetition increased activation in a lateral region of the left mid superior temporal gyrus but critically, this area is not specific to auditory word processing, it is also activated in response to environmental sounds. There were no reading specific activations, even in the areas previously claimed as visual word form areas: activations were either common to reading and auditory word repetition or common to reading and picture naming. We conclude that there is no current evidence for cortical sites dedicated to visual or auditory word form processing.     

不同情绪载体的神经活动及其异同——脑成像研究的ALE元分析

情绪识别一直是学界关注的热点。虽然已有研究探讨了动态面孔表情、动态身体表情和声音情绪的脑机制, 但对每种情绪载体的整体认识相对不完善, 同时对不同情绪载体之间神经机制的共性和区别知之甚少。因此, 本研究首先通过三项独立的激活似然估计元分析来识别每种情绪模式的大脑激活区域, 然后进行对比分析以评估三种情绪载体之间共同的和独特的神经活动。结果显示, 动态面孔表情的大脑活动包括广泛的额叶、枕叶、颞叶和部分顶叶皮层以及海马、小脑、丘脑、杏仁核等皮层下区域; 动态身体表情的激活集中于颞/枕叶相关脑区以及小脑和海马; 声音情绪则引起了颞叶、额叶、杏仁核、尾状核和脑岛的激活。联合分析表明, 三种情绪载体跨模态激活了左侧颞中回和右侧颞上回。对比分析的结果证明了视觉刺激比听觉刺激更占优势, 动态面孔表情尤为突出, 同时动态身体表情也发挥着重要作用, 但声音情绪有其独特性。总之, 这些发现验证和拓展了三种情绪载体的现有神经模型, 揭示了情绪处理中心的、普遍性的区域, 但每种情绪载体又有自己可靠的特异性神经回路。     

Brain activation during semantic processing in autism spectrum disorders via functional magnetic resonance imaging

Language and communication deficits are core features of autism spectrum disorders (ASD), even in high-functioning adults with ASD. This study investigated brain activation patterns using functional magnetic resonance imaging in right-handed adult males with ASD and a control group, matched on age, handedness, and verbal IQ. Semantic processing in the controls produced robust activation in Broca's area (left inferior frontal gyrus) and in superior medial frontal gyrus and right cerebellum. The ASD group had substantially reduced Broca's activation, but increased left temporal (Wernicke's) activation. Furthermore, the ASD group showed diminished activation differences between concrete and abstract words, consistent with behavioral studies. The current study suggests Broca's area is a region of abnormal neurodevelopment in ASD, which may be linked with semantic and related language deficits frequently observed in ASD.     

音乐表演训练对神经可塑性的影响:元分析研究

音乐表演是人类最复杂和精细的技能之一。通过激活似然性评估元分析,对音乐表演训练所诱发的神经可塑性进行探究。结果发现,音乐表演者与非音乐家在左侧小脑、双侧中央前回、双侧颞上回、左侧额下回、双侧顶下小叶以及右侧脑岛等脑区存在差异。这些脑区与听觉、运动以及多通道信息整合等加工有关。未来研究应从不同音乐表演训练诱发的神经适应性出发,进一步探究音乐表演训练与大脑可塑性之间的关联。     

Neural responses to morphological, syntactic, and semantic properties of single words: an fMRI study

Dissociations in the recognition of specific classes of words have been documented in brain-injured populations. These include deficits in the recognition and production of morphologically complex words as well as impairments specific to particular syntactic classes such as verbs. However, functional imaging evidence for distinctions among the neural systems underlying these dissociations has been inconclusive. We explored the neural systems involved in processing different word classes in a functional Magnetic Resonance Imaging study, contrasting four groups of words co-varying morphological complexity (simple, monomorphemic words vs complex derived or inflected words) and syntactic class (verbs vs nouns/adjectives). Subtraction of word from letter string processing showed activation in left frontal and temporal lobe regions consistent with prior studies of visual word processing. No differences were observed for morphologically complex and simple words, despite adequate power to detect stimulus specific effects. A region of posterior left middle temporal gyrus showed significantly increased activation for verbs. Post hoc analyses showed that this elevated activation could also be related to semantic properties of the stimulus items (verbs have stronger action associations than nouns, and action association is correlated with activation). Results suggest that semantic as well as syntactic factors should be considered when assessing the neural systems involved in single word comprehension.     

The question shapes the answer: the neural correlates of task differences reveal dynamic semantic processing

Task effects in semantic processing were investigated by contrasting the neural activation associated with two semantic categorization tasks (SCT) using event-related fMRI. The two SCTs involved different decision categories: is it an animal? vs. is it a concrete thing? Participants completed both tasks and, across participants, the same core set of items were presented in both tasks. Results showed task differences in the neural activation associated with these items: in the animal SCT there was greater activation in a number of frontal and temporal regions, including left superior and middle temporal gyri, while in the concrete SCT there was greater activation in left medial frontal gyrus and bilaterally in the precentral gyri. These results are interpreted as evidence of top-down modulation of semantic processing; participants make adjustments to optimize performance in a given task and these adjustments have consequences for the activation observed.