女性面孔吸引力的加工及其对男性诚实道德行为的影响:一项ERP研究

研究考察了不同女性面孔吸引力情境对男性被试诚实道德决策行为的影响,同时采用ERP技术对社会情境中面孔吸引力的信息加工方式特点进行探究。结果发现,高面孔吸引力记录员情境中被试倾向更加真实地报告自己的预测结果而表现出更多诚实的道德决策;ERP结果则发现高吸引力记录员面孔较之于低吸引力记录员面孔在反应提示界面在大脑中后部诱发更大的早期N200成分。结果提示,在与面孔审美评价无关的社会情境中个体面孔的吸引力信息能够被快速识别与自动化加工,同时也会直接促进他人自身的道德行为水平。     

双语即时切换下非目标语言语音和语义的激活状态

本研究采用双语即时切换范式, 探讨非熟练中英双语者在对目标语言(启动词)语音或语义的加工过程中非目标语言的激活状态。实验1设置了与启动词的翻译对等词存在语音相关或无关的两类配对词, 要求被试进行语音判断任务, 结果表明, 不论哪种切换条件, 两类配对词在反应时和P200成分上都没有差异, 说明目标语言在语音加工过程中非目标语言的语音层面没有得到自动激活, 从而没有产生启动效应。实验2则设置了语义相关和无关配对词, 并进行语义判断任务, 结果在两种切换条件下都发现明显的语义启动效应及N400差异, 说明非目标语言在语义层面上有得到自动激活, 但激活的程度表现出切换方向上的不一致, L1-L2切换下的语义启动量要明显大于L2-L1, 并且L1-L2的N400差异主要表现在前部脑区, 持续时间更久, 而L2-L1的N400差异主要表现在后部脑区, 但持续时间较短, 表明对于非熟练的双语者来说, 不同切换方向下对共享语义表征的激活加工是不一样的。     

任务与字频对汉字情绪启动反转效应的影响

本研究使用ERP技术对比了效价判断与真假字判断两种任务形式下的汉字情绪启动效应。结果发现,在效价判断任务中高频目标字出现情绪启动的反转效应,效价不一致比一致条件下反应时短,诱发了较大的P200;低频目标字出现情绪启动的一致性效应,效价一致比不一致条件下反应时短,诱发了较大的P200与N400。真假字判断任务中高频和低频目标字均出现情绪启动的一致性效应。情绪启动的反转效应依赖于刺激材料的可通达性与注意导向,启动字与目标字的反应竞争关系导致了情绪启动的反转效应。     

Time-course of hemispheric preference for processing contralateral relevant shapes: P1pc, N1pc, N2pc, N3pc

A most sensitive and specific electrophysiological indicator of selective processing of visual stimuli is the N2pc component. N2pc is a negative EEG potential peaking 250 ms after stimulus onset, recorded from posterior sites contralateral to relevant stimuli. Additional deflections preceding or following N2pc have been obtained in previous studies, possibly produced by specific stimulus features or specific prime-target sequences. To clarify the entire time-course of the contralateral- ipsilateral (C-I) difference recorded from the scalp above visual cortex in response to left-right pairs of targets and distracters, C-I differences were here compared between two types of stimuli and between stimuli that were or were not preceded by masked neutral primes. The C-I difference waveform consisted of several peaks, termed here P1pc (60-100 ms after target onset), N1pc (120-160 ms), N2pc (220-280 ms), and N3pc (360-400 ms). Being markedly enhanced when stimuli were preceded by the neutral primes, P1pc may indicate a response to stimulus change. Also, when stimuli were primed, N2pc reached its peak earlier, thereby tending to merge with N1pc. N3pc seemed to increase when target discrimination was difficult. N1pc, N2pc, and N3pc appear as three periods of one process. N3pc probably corresponds to L400 or SPCN as described in other studies. These observations suggest that the neurophysiological basis of stimulus-driven focusing of attention on target stimuli is a process that lasts for hundreds of milliseconds, with the relevant hemisphere being activated in an oscillating manner as long as required by the task.     

面孔识别特异性本质的ERP研究

本研究记录了16名被试在完成有整体结构变化和局部特征变化的面孔/房屋图片的一致性判断时的脑内时程变化,以期对面孔识别的特异性本质进行探讨。结果显示,N170波幅和潜伏期的刺激类型主效应显著;面孔/房屋所诱发的N170成分在波幅和潜伏期上均不存在加工方式上的显著差异。晚期成分(300～700ms)上也得到类似的结果。这表明:面孔与房屋(非面孔)的加工在早期和晚期成分上都有差异性,体现出面孔的加工在早期视觉刺激的加工和晚期识别的加工上都具有特异性;晚期识别加工的脑电结果不支持"面孔识别是整体的,结构的,而非面孔客体的识别是局部的,基于特征的"加工观点。     

甲型H1N1流感大流行2周年记

2009年4月,墨西哥暴发甲型H1N1流感疫情,并迅速蔓延至全球。2009年6月11日,世界卫生组织宣布进入流感大流行,直到2010年8月10日世卫组织宣布世界步入流感大流行后期。自流感暴发已经2年过去了,回顾整个过程我们从中可以学到许多经验和教训,并随时准备应对将来可能发生的新的流感疫情。     

2009年-2011年广州市甲型H1N1流感监测定量研究

本文对广州市2009年7月～2011年1月的发热呼吸道监测数据进行了定量分析,并在此分析的基础上提出了相关政策建议,比如加强人群分类管理、加快疫苗研制、避免抗病毒药物的滥用、重视健康管理和健康教育以及遵循预防控制原则等。     

Electrophysiological correlates of the composite face illusion: Disentangling perceptual and decisional components of holistic face processing in the human brain

When the bottom halves of two faces differ, people’s behavioral judgment of the identical top halves of those faces is impaired: they report that the top halves are different, and/or take more time than usual to provide a response. This behavioral measure is known as the composite face effect (CFE) and has traditionally been taken as evidence that faces are perceived holistically. Recently, however, it has been claimed that this effect is driven almost entirely by decisional, rather than perceptual, factors ( Richler, Gauthier, Wenger, & Palmeri, 2008). To disentangle the contribution of perceptual and decisional brain processes, we aimed to obtain an event-related potential (ERP) measure of the CFE at a stage of face encoding ( Jacques & Rossion, 2009) in the absence of a behavioral CFE effect. Sixteen participants performed a go/no-go task in an oddball paradigm, lifting a finger of their right or left hand when the top half of a face changed identity. This change of identity of the top of the face was associated with an increased ERP signal on occipito-temporal electrode sites at the N170 face-sensitive component (∼160 ms), the later decisional P3b component, and the lateralized readiness potential (LRP) starting at ∼350 ms. The N170 effect was observed equally early when only the unattended bottom part of the face changed, indicating that an identity change was perceived across the whole face in this condition. Importantly, there was no behavioral response bias for the bottom change trials, and no evidence of decisional biases from electrophysiological data (no P3b and LRP deflection in no-go trials). These data show that an early CFE can be measured in ERPs in the absence of any decisional response bias, indicating that the CFE reflects primarily the visual perception of the whole face.     

Functional characterisation of the extrastriate body area based on the N1 ERP component

Electrophysiological and functional neuroimaging evidence points to the existence of neural populations that respond strongly and selectively to the appearance of the human body and its parts. However, the relationship between ERP and fMRI markers of these populations remains unclear. Here we used a previously identified functional dissociation between two body-selective regions identified with fMRI (extrastriate body area or EBA; fusiform body area or FBA) in order to better understand the source of a body-selective N1 ERP component. Specifically, we compared the magnitude of the N1 elicited by images of fingers, hands, arms and bodies to that obtained for hierarchically-matched control stimuli. We found close agreement between the pattern of body-part selectivity exhibited by N1, and the pattern of BOLD selectivity elicited in a previous study by the same type of stimuli in EBA (in contrast to FBA). We interpret these findings as evidence for EBA as the primary generator of the body-selective N1 component. Our results are an example of the use of functional criteria to distinguish among the possible neural sources of ERP markers.     

甲型H1N1流感普通型与重症型的处理

本文回顾性总结历史上几次世界性甲型流感流行和2009年H1N1流感流行情况。概述了2009年H1N1流感普通型病例的临床处理。重点阐述2009年H1N1流感重症型病例的高危人群、发生的危险因素以及临床表现。特别强调重症型流感抗病毒治疗的重要性及适应证。同时提醒关注神经氨酸酶抑制剂应用的耐药问题。