时间：5月7日 (周四)  18:00-20:00

地点：恕园28号楼205室

主题：工作进展和文献报告

1、工作进展：生理条件下小胶质细胞在睡眠-觉醒节律中的作用

主讲：陶双科 同学

2、文献汇报：工作记忆中的视觉搜索

主讲：张晓圳 同学

3、文献汇报：基于MRI的足月儿与早产儿的脑髓鞘形成的时空发育模式及其临床关联

主讲：马逸凡 同学

欢迎老师与同学们踊跃出席！

脑科学研究所

文献详细信息

1、题目：Visual Search Within Working Memory  

期刊名称：Journal of Experimental Psychology: General   IF：4.1   JCR：Q1   中科院：1区

摘要：

Attention and working memory are 2 key pillars of cognition. Despite much research, there are important aspects about the relationship between the 2 constructs that are not well understood. Here we explore the similarity in the mechanisms that select and update working memory to those that guide attention during perception, such as in visual search. We use a memory search task where participants memorize a display of objects on a grid. During memory maintenance, participants are instructed to update the spatial positions of a subset of objects. The speed of the updating process should reflect the accessibility of the to-be -updated subset. Using this task, we explored whether landmark findings in visual search would hold true for memory search. In Experiment 1, we found a search asymmetry—it was easier to access memory representations defined by a feature than defined by the lack of a feature. In Experiment 2, we found target-distractor similarity effects— updating a single target was easier when the distractors were farther away in feature space. In Experiment 3, we found a feature versus conjunction benefit—access times were much faster for instructions to move objects defined by only 1 feature (e.g., all triangles) as opposed to a conjunction of features (e.g., all red triangles). In Experiment 4, we find a set-size effect— update times increased with the number of items in memory, particularly for conjunctive stimuli. Taken together, our results suggest a common coding and selection scheme for working memory and perceptual representations.

2、题目：Spatiotemporal Development and Clinical Correlates of MRI-based Brain Myelination in Term- and Preterm-born Children

期刊名称：Radiology   IF:15.2   SCI:Q1   中科院:1区

摘要：

Background: The spatiotemporal progression of myelination and its associations with neurodevelopmental outcomes and perinatal risks remain insufficiently characterized in large-scale longitudinal studies.

Purpose: To characterize the myelination process across early childhood using the T1-weighted to T2-weighted MRI signal intensity ratio as a semiquantitative marker of myelination and elucidate its relationship with perinatal adversities and neurodevelopmental outcomes.

Materials and Methods: In this multicenter study, 3.0-T MRI data of term-born children from the Baby Connectome Project (BCP) (September 2016 to May 2020) and preterm-born infants collected locally at Zhejiang University (ZJU) (January 2019 to September 2020) were analyzed to extractthe T1-weighted to T2-weighted signal intensity ratio. Statistical analyses included nonnegative matrix factorization to identify regions with distinct patterns of myelination (PMs), generalized additive mixed-effects models to characterize trajectories, and mediation and correlation analyses to assess brain-behavior relationships.

Results: In total, 412 children (mean age, 14.6 months ± 13.5 [SD]; 214 male; 307 from BCP and 105 from the ZJU local dataset) with 779 imaging sessions were included. Spatiotemporal maps revealed rapid myelination in the first 2 years of life. Seven PMs with unique developmental trajectories were identified. A full mediating effect of T1-weighted to T2-weighted signal intensity ratio was found on the age-related change of repetitive motor frequency (indirect effect β range, −0.40 to −0.24; false discovery rate [FDR]–corrected P < .001) and restricted behavior frequency(β range, −0.33 to −0.22; FDR-corrected P < .05). Compared with moderately preterm infants, extremely preterm infants had slower myelination across all PMs (t value range, 2.71–3.27; P < .01) and showed delayed fine motor skills (t = −2.47, [P = .03] at 4 months; t = −4.00 [P = .02] at 8 months). The spatiotemporal pattern of myelination in extremely preterm infants was less correlated with the normative term-born group (r = 0.807; P = .03) than that of moderately preterm infants (r = 0.952; P < .001).

Conclusion: The T1-weighted to T2-weighted signal intensity ratio from MRI was used to identify heterogeneous PMs and elucidated a critical link between myelination and neurodevelopmental outcomes in both term- and preterm-born children.