社会性预期优势效应的神经机制

社会性预期优势效应是指个体在预期条件下的信息加工能力显著优于非预期条件。探讨社会性预期优势效应的神经机制, 是心理学家和认知神经科学家关注的一项重要课题。社会性预期编码模型可以为预期静默效应(预期刺激引起的神经活动减弱)提供理论解释, 但该模型不能解释社会性预期刺激诱发的增强神经活动。因此, 研究1和研究2将考察无意识和意识社会性注意在社会性预期编码模型中的作用, 从而将它们整合到该模型中。研究3不再局限于对社会性预期编码模型的考察, 而是扩展到对预期转换机制的探讨, 最终将社会性预期编码模型和预期转换机制整合在预期节俭化框架之下。对于社会性预期优势效应神经机制的研究不仅能够完善社会性预期编码模型, 还有助于拓宽社会性预期研究的视角。     

共情特质的神经生物学基础

共情特质的个体差异是心理学研究领域中的一个重要主题。近些年来, 研究者开始关注导致人们共情能力高低有别的神经生物学基础问题。研究发现, 不论是情感共情特质还是认知共情特质, 其个体差异均在大脑进行共情反应、脑结构态及静息态功能连接上有所体现。它们共同说明, 人们的共情能力与其具身模仿能力, 情感加工能力及情绪理解能力密切相关。不仅如此, 共情特质也具有高度的可遗传性, 一些基因类型与该能力存在着紧密的关系。在今后的研究中, 需要扩展对共情特质结构的进一步认识, 关注环境和基因在影响共情特质上存在的交互作用, 并努力将理论研究成果应用于共情能力训练和提高的临床实践中。     

发展性阅读障碍的脑区连接异常

过去几十年中, 研究者基于脑区功能定位的思想对发展性阅读障碍的神经机制进行了大量的研究, 揭示出阅读障碍者在特定脑区的异常。近些年, 考虑到阅读加工过程的复杂性以及需要多脑区协同参与的特点, 越来越多的研究者从脑区连接的角度探讨阅读障碍的神经机制。结果发现阅读障碍者在阅读相关脑区间的白质结构连接和功能连接上均表现出异常, 这说明阅读技能受损和脑区连接异常之间存在着密切的联系。未来的研究还需进一步探讨脑区连接异常和特定脑区异常之间的关系, 以及结合基因、脑、行为和环境等多个因素探寻阅读障碍的发生机制。     

The neural correlates of everyday recognition memory

We used a novel automatic camera, SenseCam, to create a recognition memory test for real-life events. Adapting a 'Remember/Know' paradigm, we asked healthy undergraduates, who wore SenseCam for 2 days, in their everyday environments, to classify images as strongly or weakly remembered, strongly or weakly familiar or novel, while brain activation was recorded with functional MRI. Overlapping, widely distributed sets of brain regions were activated by recollected and familiar stimuli. Within the medial temporal lobes, 'Remember' responses specifically elicited greater activity in the right anterior and posterior parahippocampal gyrus than 'Know' responses. 'New' responses activated anterior parahippocampal regions. A parametric analysis, across correctly recognised items, revealed increasing activation in the right hippocampus and posterior parahippocampal gyrus (pPHG). This may reflect modulation of these regions by the degree of recollection or, alternatively, by increasing memory strength. Strong recollection elicited greater activity in the left posterior hippocampus/pPHG than weak recollection indicating that this region is specifically modulated by the degree of recollection.     

Cognitive control of a simple mental image in patients with obsessive--compulsive disorder

The nature of obsessions has led researchers to try to determine if the main problem in obsessive-compulsive disorder (OCD) is impaired inhibitory control. Previous studies report that the effort to suppress is one of the factors that increase the frequency of obsessive thoughts. Based on these results and those of the present study that suggest inferior parietal lobe (IPL) abnormality in OCD and findings of a recent study that reported the importance of the right posterior parietal cortex in cognitive control of a simple mental image, the present cognitive control paradigm study aimed to determine whether there is a difference in brain dynamics between OCD patients and non-obsessive controls while performing tasks that necessitate cognitive control of a simple mental image, and whether the right posterior parietal region is one of the regions in which a difference in activity between the OCD patients and controls would be observed. Functional brain imaging was performed while the participants attempted to suppress, imagine, or manipulate a mental image. The general linear model showed that there was a main effect of group and main effect of task. Accordingly, in all contrasts (suppression minus free-imagination, erasing minus free-imagination, and imagination minus free-imagination), the right IPL, right posterior cingulate cortex, and right superior frontal gyrus activity were lower in the OCD patients than in the healthy controls. These results and the observed correlations between activity levels, and symptom and subjective performance scores are discussed. In conclusion, the results of the present study and those of previous studies suggest that the main problem in OCD might be difficulty activating the right frontoparietal networks during tasks that require cognitive control, which might result in the intrusiveness of obsessive thoughts.     

The impact of continuity editing in narrative film on event segmentation

Filmmakers use continuity editing to engender a sense of situational continuity or discontinuity at editing boundaries. The goal of this study was to assess the impact of continuity editing on how people perceive the structure of events in a narrative film and to identify brain networks that are associated with the processing of different types of continuity editing boundaries. Participants viewed a commercially produced film and segmented it into meaningful events, while brain activity was recorded with functional magnetic resonance imaging (MRI). We identified three degrees of continuity that can occur at editing locations: edits that are continuous in space, time, and action; edits that are discontinuous in space or time but continuous in action; and edits that are discontinuous in action as well as space or time. Discontinuities in action had the biggest impact on behavioral event segmentation, and discontinuities in space and time had minor effects. Edits were associated with large transient increases in early visual areas. Spatial-temporal changes and action changes produced strikingly different patterns of transient change, and they provided evidence that specialized mechanisms in higher order perceptual processing regions are engaged to maintain continuity of action in the face of spatiotemporal discontinuities. These results suggest that commercial film editing is shaped to support the comprehension of meaningful events that bridge breaks in low-level visual continuity, and even breaks in continuity of spatial and temporal location.     

Brain networks associated with sublexical properties of Chinese characters

Cognitive models of reading all assume some division of labor among processing pathways in mapping among print, sound and meaning. Many studies of the neural basis of reading have used task manipulations such as rhyme or synonym judgment to tap these processes independently. Here we take advantage of specific properties of the Chinese writing system to test how differential availability of sublexical information about sound and meaning, as well as the orthographic structure of characters, pseudo-characters and “artificial” control stimuli influence brain activation in the context of the same one-back task. Analyses combine a data-driven approach that identifies temporally coherent patterns of activity over the course of the entire experiment with hypothesis-testing based on the correlation of these patterns with predictors for different stimulus classes. The results reveal a large network of task-related activity. Both the extent of this network and activity in regions commonly observed in studies of Chinese reading are apparently related to task difficulty. Other regions, including temporo-parietal cortex, were sensitive to particular sublexical functional units in mapping among print, sound, and meaning.     

Neural correlates of phonological processing in speech sound disorder: a functional magnetic resonance imaging study

Speech sound disorders (SSD) are the largest group of communication disorders observed in children. One explanation for these disorders is that children with SSD fail to form stable phonological representations when acquiring the speech sound system of their language due to poor phonological memory (PM). The goal of this study was to examine PM in individuals with histories of SSD employing functional MR imaging (fMRI). Participants were six right-handed adolescents with a history of early childhood SSD and seven right-handed matched controls with no history of speech and language disorders. We performed an fMRI study using an overt non-word repetition (NWR). Right lateralized hypoactivation in the inferior frontal gyrus and middle temporal gyrus was observed. The former suggests a deficit in the phonological processing loop supporting PM, while the later may indicate a deficit in speech perception. Both are cognitive processes involved in speech production. Bilateral hyperactivation observed in the pre and supplementary motor cortex, inferior parietal, supramarginal gyrus and cerebellum raised the possibility of compensatory increases in cognitive effort or reliance on the other components of the articulatory rehearsal network and phonologic store. These findings may be interpreted to support the hypothesis that individuals with SSD may have a deficit in PM and to suggest the involvement of compensatory mechanisms to counteract dysfunction of the normal network.     

Functional brain activation differences in stuttering identified with a rapid fMRI sequence

The purpose of this study was to investigate whether brain activity related to the presence of stuttering can be identified with rapid functional MRI (fMRI) sequences that involved overt and covert speech processing tasks. The long-term goal is to develop sensitive fMRI approaches with developmentally appropriate tasks to identify deviant speech motor and auditory brain activity in children who stutter closer to the age at which recovery from stuttering is documented. Rapid sequences may be preferred for individuals or populations who do not tolerate long scanning sessions. In this report, we document the application of a picture naming and phoneme monitoring task in 3 min fMRI sequences with adults who stutter (AWS). If relevant brain differences are found in AWS with these approaches that conform to previous reports, then these approaches can be extended to younger populations. Pairwise contrasts of brain BOLD activity between AWS and normally fluent adults indicated the AWS showed higher BOLD activity in the right inferior frontal gyrus (IFG), right temporal lobe and sensorimotor cortices during picture naming and higher activity in the right IFG during phoneme monitoring. The right lateralized pattern of BOLD activity together with higher activity in sensorimotor cortices is consistent with previous reports, which indicates rapid fMRI sequences can be considered for investigating stuttering in younger participants.Educational objectives: The reader will learn about and be able to describe the: (1) use of functional MRI to study persistent developmental stuttering; (2) differences in brain activation between persons who stutter and normally fluent speakers; and (3) potential benefit of time efficient fMRI sequences combined with a range of speech processing tasks for investigating stuttering in younger populations.     

Neural correlates in the processing of phoneme-level complexity in vowel production

We investigated how articulatory complexity at the phoneme level is manifested neurobiologically in an overt production task. fMRI images were acquired from young Korean-speaking adults as they pronounced bisyllabic pseudowords in which we manipulated phonological complexity defined in terms of vowel duration and instability (viz., COMPLEX: /ti?i/ >> MID-COMPLEX: /tiye/ >> SIMPLE: /tii/). Increased activity in the left inferior frontal gyrus (Brodmann Areas (BA) 44 and 47), supplementary motor area and anterior insula was observed for the articulation of COMPLEX sequences relative to MID-COMPLEX; this was the case with the articulation of MID-COMPLEX relative to SIMPLE, except that the pars orbitalis (BA 47) was dominantly identified in the Broca’s area. The differentiation indicates that phonological complexity is reflected in the neural processing of distinct phonemic representations, both by recruiting brain regions associated with retrieval of phonological information from memory and via articulatory rehearsal for the production of COMPLEX vowels. In addition, the finding that increased complexity engages greater areas of the brain suggests that brain activation can be a neurobiological measure of articulo-phonological complexity, complementing, if not substituting for, biomechanical measurements of speech motor activity.