Functional MRI of conventional and anomalous metaphors in Mandarin Chinese

This study looks at whether conventional and anomalous metaphors are processed in different locations in the brain while being read when compared with a literal condition in Mandarin Chinese. We find that conventional metaphors differ from the literal condition with a slight amount of increased activation in the right inferior temporal gyrus. In addition, when the anomalous metaphor condition is compared with the literal condition, increased activation occurs bilaterally in the frontal and temporal gyri. Lastly, the comparison between the anomalous and conventional metaphor conditions shows bilateral activation in the middle frontal gyrus and the precentral gyrus, and right-hemisphere activation in the superior frontal gyrus. Left hemisphere activation is found in the inferior frontal gyrus and fusiform gyrus. The left hemisphere activation in the frontal and temporal gyri point to the recruitment of traditional language-based areas for anomalous metaphor sentences, while the right-hemisphere activation found suggests that remote associations are being formed. In short, our study supports the idea that metaphors are not a homogenous type of figurative language and that distinguishing between different types of metaphors will advance theories of language comprehension.     

The effects of simulated stuttering and prolonged speech on the neural activation patterns of stuttering and nonstuttering adults

Functional magnetic resonance imaging was used to investigate the neural correlates of passive listening, habitual speech and two modified speech patterns (simulated stuttering and prolonged speech) in stuttering and nonstuttering adults. Within-group comparisons revealed increased right hemisphere biased activation of speech-related regions during the simulated stuttered and prolonged speech tasks, relative to the habitual speech task, in the stuttering group. No significant activation differences were observed within the nonstuttering participants during these speech conditions. Between-group comparisons revealed less left superior temporal gyrus activation in stutterers during habitual speech and increased right inferior frontal gyrus activation during simulated stuttering relative to nonstutterers. Stutterers were also found to have increased activation in the left middle and superior temporal gyri and right insula, primary motor cortex and supplementary motor cortex during the passive listening condition relative to nonstutterers. The results provide further evidence for the presence of functional deficiencies underlying auditory processing, motor planning and execution in people who stutter, with these differences being affected by speech manner.     

An event-related fMRI study of syntactic and semantic violations

We used event-related functional magnetic resonance imaging to identify brain regions involved in syntactic and semantic processing. Healthy adult males read well-formed sentences randomly intermixed with sentences which either contained violations of syntactic structure or were semantically implausible. Reading anomalous sentences, as compared to well-formed sentences, yielded distinct patterns of activation for the two violation types. Syntactic violations elicited significantly greater activation than semantic violations primarily in superior frontal cortex. Semantically incongruent sentences elicited greater activation than syntactic violations in the left hippocampal and parahippocampal gyri, the angular gyri bilaterally, the right middle temporal gyrus, and the left inferior frontal sulcus. These results demonstrate that syntactic and semantic processing result in nonidentical patterns of activation, including greater frontal engagement during syntactic processing and larger increases in temporal and temporo-parietal regions during semantic analyses.     

Neural correlates of music recognition in Down syndrome

The brain mechanisms that subserve music recognition remain unclear despite increasing interest in this process. Here we report the results of a magnetoencephalography experiment to determine the temporal dynamics and spatial distribution of brain regions activated during listening to a familiar and unfamiliar instrumental melody in control adults and adults with Down syndrome (DS). In the control group, listening to the familiar melody relative to the unfamiliar melody, revealed early and significant activations in the left primary auditory cortex, followed by activity in the limbic and sensory-motor regions and finally, activation in the motor related areas. In the DS group, listening to the familiar melody relative to the unfamiliar melody revealed increased significant activations in only three regions. Activity began in the left primary auditory cortex and the superior temporal gyrus and was followed by enhanced activity in the right precentral gyrus. These data suggest that familiar music is associated with auditory–motor coupling but does not activate brain areas involved in emotional processing in DS. These findings reveal new insights on the neural basis of music perception in DS as well as the temporal course of neural activity in control adults.     

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。     

Structure and stimulus familiarity: a study of memory in chess-players with functional magnetic resonance imaging

A grandmaster and an international chess master were compared with a group of novices in a memory task with chess and non-chess stimuli, varying the structure and familiarity of the stimuli, while functional magnetic resonance images were acquired. The pattern of brain activity in the masters was different from that of the novices. Masters showed no differences in brain activity when different degrees of structure and familiarity where compared; however, novices did show differences in brain activity in such contrasts. The most important differences were found in the contrast of stimulus familiarity with chess positions. In this contrast, there was an extended brain activity in bilateral frontal areas such as the anterior cingulate and the superior, middle, and inferior frontal gyri; furthermore, posterior areas, such as posterior cingulate and cerebellum, showed great bilateral activation. These results strengthen the hypothesis that when performing a domain-specific task, experts activate different brain systems from that of novices. The use of the experts-versus-novices paradigm in brain imaging contributes towards the search for brain systems involved in cognitive processes.     

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.     

Cortical integration of audio–visual speech and non-speech stimuli

Using fMRI we investigated the neural basis of audio–visual processing of speech and non-speech stimuli using physically similar auditory stimuli (speech and sinusoidal tones) and visual stimuli (animated circles and ellipses). Relative to uni-modal stimuli, the different multi-modal stimuli showed increased activation in largely non-overlapping areas. Ellipse-Speech, which most resembles naturalistic audio–visual speech, showed higher activation in the right inferior frontal gyrus, fusiform gyri, left posterior superior temporal sulcus, and lateral occipital cortex. Circle-Tone, an arbitrary audio–visual pairing with no speech association, activated middle temporal gyri and lateral occipital cortex. Circle-Speech showed activation in lateral occipital cortex, and Ellipse-Tone did not show increased activation relative to uni-modal stimuli. Further analysis revealed that middle temporal regions, although identified as multi-modal only in the Circle-Tone condition, were more strongly active to Ellipse-Speech or Circle-Speech, but regions that were identified as multi-modal for Ellipse-Speech were always strongest for Ellipse-Speech. Our results suggest that combinations of auditory and visual stimuli may together be processed by different cortical networks, depending on the extent to which multi-modal speech or non-speech percepts are evoked.     

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.     

Multimodal action representation in human left ventral premotor cortex

We used functional magnetic resonance imaging (fMRI) to investigate the neural systems responding to the sight and to the sound of an action. Subjects saw a video of paper tearing in silence (V), heard the sound of paper tearing (A), and saw and heard the action simultaneously (A + V). Compared to a non-action control stimulus, we found that hearing action sounds (A) activated the anterior inferior frontal gyrus and middle frontal gyrus in addition to primary auditory cortex. The anterior inferior frontal gyrus, which is known to be activated by environmental sounds, also seems to be involved in recognizing actions by sound. Consistent with previous research, seeing an action video (V) compared with seeing a non-action video activated the premotor cortex, intraparietal cortex, and the pars opercularis of the inferior frontal gyrus. An A + V facilitation effect was found in the ventral premotor cortex on the border of areas 44, 6, 3a, and 3b for the action stimuli but not for the control stimuli. This region may be involved in integrating multimodal information about actions. These data provide evidence that the ventral premotor cortex may provide an action representation that abstracts across both agency (self and other) and sensory modality (hearing and seeing). This function may be an important precursor of language functions.     

Differential prefrontal-temporal neural correlates of semantic processing in children

This study used functional magnetic resonance imaging (fMRI) to examine brain-behavior correlations in a group of 16 children (9- to 12-year-olds). Activation was measured during a semantic judgment task presented in either the visual or auditory modality that required the individual to determine whether a final word was related in meaning to one of two previous words (e.g., found-tank-lost). The main finding was that higher performers (i.e., accuracy) were associated with more activation in posterior representational systems including the inferior and middle temporal gyri, whereas lower performers were associated with more activation in anterior regions including the inferior and middle frontal gyri. This pattern of results was interpreted as reflecting an elaborated semantic representational system in temporal areas for the high accuracy performers that allowed them to efficiently and accurately make meaning based judgments. The low accuracy performers may have an inaccurate or weakly interconnected semantic system that results in greater use of frontal areas in a feature selection process.     

Neural correlates of metaphor processing: The roles of figurativeness,familiarity and difficulty

There is currently much interest in investigating the neural substrates of metaphor processing. In particular, it has been suggested that the right hemisphere plays a special role in the comprehension of figurative (non-literal) language, and in particular metaphors. However, some studies find no evidence of right hemisphere involvement in metaphor comprehension (e.g. [Lee, S. S., & Dapretto, M. (2006). Metaphorical vs. literal word meanings: fMRI evidence against a selective role of the right hemisphere. NeuroImage, 29, 536–544; Rapp, A. M., Leube, D. T., Erb, M., Grodd, W., & Kircher, T. T. J. (2004). Neural correlates of metaphor processing. Cognitive Brain Research, 20, 395–402]). We suggest that lateralization differences between literal and metaphorical language may be due to factors such as differences in familiarity ([Schmidt, G. L., DeBuse, C. J., & Seger, C. A. (2007). Right hemisphere metaphor processing? Characterizing the lateralization of semantic processes. Brain and Language, 100, 127–141]), or difficulty ([Bookheimer, S. (2002). Functional MRI of language: New approaches to understanding the cortical organization of semantic processing. Annual Review of Neuroscience, 25, 151–188; Rapp, A. M., Leube, D. T., Erb, M., Grodd, W., & Kircher, T. T. J. (2004). Neural correlates of metaphor processing. Cognitive Brain Research, 20, 395–402]) in addition to figurativeness. The purpose of this study was to separate the effects of figurativeness, familiarity, and difficulty on the recruitment of neural systems involved in language, in particular right hemisphere mechanisms. This was achieved by comparing neural activation using functional magnetic resonance imaging (fMRI) between four conditions: literal sentences, familiar and easy to understand metaphors, unfamiliar and easy to understand metaphors, and unfamiliar and difficult to understand metaphors. Metaphors recruited the right insula, left temporal pole and right inferior frontal gyrus in comparison with literal sentences. Familiar metaphors recruited the right middle frontal gyrus when contrasted with unfamiliar metaphors. Easy metaphors showed higher activation in the left middle frontal gyrus as compared to difficult metaphors, while difficult metaphors showed selective activation in the left inferior frontal gyrus as compared to easy metaphors. We conclude that the right hemisphere is involved in metaphor processing and that the factors of figurativeness, familiarity and difficulty are important in determining neural recruitment of semantic processing.     

Neural activation pattern in self-deceivers

While deception is a conscious cognitive effort and self-deception is an unconscious cognitive effort. Such effort possibly shapes the working memory and generates a neural activation pattern in self-deception. Little attempt was made to identify activation pattern in self-deception. The present study investigated the phenomenon of self-deception by increasing the working memory functions using a boxcar design. functional magnetic resonance imaging (fMRI) revealed more activation in bilateral inferior parietal lobule (BA 40), superior parietal lobule (BA 7), middle frontal gyrus (BA 9), medial frontal gyrus (BA 6), thalamus and cerebellum. Activated areas in frontal and parietal cortex suggest significant role of working memory during self-deception.     

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。     

Multichannel fNIRS assessment of overt and covert confrontation naming

Confrontation naming tasks assess cognitive processes involved in the main stage of word production. However, in fMRI, the occurrence of movement artifacts necessitates the use of covert paradigms, which has limited clinical applications. Thus, we explored the feasibility of adopting multichannel functional near-infrared spectroscopy (fNIRS) to assess language function during covert and overt naming tasks. Thirty right-handed, healthy adult volunteers underwent both naming tasks and cortical hemodynamics measurement using fNIRS. The overt naming task recruited the classical left-hemisphere language areas (left inferior frontal, superior and middle temporal, precentral, and postcentral gyri) exemplified by an increase in the oxy-Hb signal. Activations were bilateral in the middle and superior temporal gyri. However, the covert naming task recruited activation only in the left-middle temporal gyrus. The activation patterns reflected a major part of the functional network for overt word production, suggesting the clinical importance of fNIRS in the diagnosis of aphasic patients.     

The effect of sublexical and lexical frequency on speech production: An fMRI investigation

There is no consensus regarding the fundamental phonetic units that underlie speech production. There is, however, general agreement that the frequency of occurrence of these units is a significant factor. Investigators often use the effects of manipulating frequency to support the importance of particular units. Studies of pseudoword production have been used to show the importance of sublexical units, such as initial syllables, phonemes, and biphones. However, it is not clear that these units play the same role when the production of pseudowords is compared to the production of real words. In this study, participants overtly repeated real and pseudowords that were similar for length, complexity, and initial syllable frequency while undergoing functional magnetic resonance imaging. Compared to real words, production of pseudowords produced greater activation in much of the speech production network, including bilateral inferior frontal cortex, precentral gyri and supplementary motor areas and left superior temporal cortex and anterior insula. Only middle right frontal gyrus showed greater activation for real words than for pseudowords. Compared to a no-speech control condition, production of pseudowords or real words resulted in activation of all of the areas shown to comprise the speech production network. Our data, in conjunction with previous studies, suggest that the unit that is identified as the basic unit of speech production is influenced by the nature of the speech that is being studied, i.e., real words as compared to other real words, pseudowords as compared to other pseudowords, or real words as compared to pseudowords.     

Motor-iconicity of sign language does not alter the neural systems underlying tool and action naming

Positron emission tomography was used to investigate whether the motor-iconic basis of certain forms in American Sign Language (ASL) partially alters the neural systems engaged during lexical retrieval. Most ASL nouns denoting tools and ASL verbs referring to tool-based actions are produced with a handshape representing the human hand holding a tool and with an iconic movement depicting canonical tool use, whereas the visual iconicity of animal signs is more idiosyncratic and inconsistent across signs. We investigated whether the motor-iconic relation between a sign and its referent alters the neural substrate for lexical retrieval in ASL. Ten deaf native ASL signers viewed photographs of tools/utensils or of actions performed with or without an implement and were asked to overtly produce the ASL sign for each object or action. The control task required subjects to judge the orientation of unknown faces. Compared to the control task, naming tools engaged left inferior and middle frontal gyri, bilateral parietal lobe, and posterior inferotemporal cortex. Naming actions performed with or without a tool engaged left inferior frontal gyrus, bilateral parietal lobe, and posterior middle temporal gyrus at the temporo-occipital junction (area MT). When motor-iconic verbs were compared with non-iconic verbs, no differences in neural activation were found. Overall, the results indicate that even when the form of a sign is indistinguishable from a pantomimic gesture, the neural systems underlying its production mirror those engaged when hearing speakers name tools or tool-based actions with speech.     

Neuroanatomical correlates of oral reading in acute left hemispheric stroke

Oral reading is a complex skill involving the interaction of orthographic, phonological, and semantic processes. Functional imaging studies with nonimpaired adult readers have identified a widely distributed network of frontal, inferior parietal, posterior temporal, and occipital brain regions involved in the task. However, while functional imaging can identify cortical regions engaged in the process under examination, it cannot identify those brain regions essential for the task. The current study aimed to identify those neuroanatomical regions critical for successful oral reading by examining the relationship between word and nonword oral reading deficits and areas of tissue dysfunction in acute stroke. We evaluated 91 patients with left hemisphere ischemic stroke with a test of oral word and nonword reading, and magnetic resonance diffusion-weighted and perfusion-weighted imaging, within 24-48 h of stroke onset. A voxel-wise statistical map showed that impairments in word and nonword reading were associated with a distributed network of brain regions, including the inferior and middle frontal gyri, the middle temporal gyrus, the supramarginal and angular gyri, and the middle occipital gyrus. In addition, lesions associated with word deficits were found to be distributed more frontally, while nonword deficits were associated with lesions distributed more posteriorly.     

Eye-gaze behaviour of expert and novice surfers in a simulated surf environment

Skilled performance in sport often relies on looking at the right place at the right time. Differences in visual behaviour can thus characterise expertise. The current study examined visual attention associated with surfing expertise. Expert (n = 12) and novice (n = 12) surfers viewed 360-degree surfing videos in a head-mounted display. Eye-gaze, presence, and engagement were measured. Experts were faster to detect approaching high, and low waves, spent more time overall attending to high-performance value areas-of-interest (AOIs; pocket, shoulder, lip), and were more physically engaged. Group differences were not found for presence or simulator sickness. Outcomes show that surfing expertise is associated with more optimal visual attention to cues informing wave approach and wave dynamics. Experts look at these areas earlier than novices, and for more time overall. The findings suggest the performance advantages of early planning of motor actions, along with moment-to-moment adjustments while surfing.     

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.