听障者语音编码的研究范式述评

对于健听者而言,语音编码在阅读中具有重要作用。听障者在阅读中是否存在语音编码？对于拼音文字而言,这个问题目前国际上存在很大的争议。中国听障者在阅读中是否使用了语音编码也逐渐开始受到重视。为了给国内研究听障者语音编码的学者提供参考,本文介绍了考察听障者语音编码研究中常用的研究范式,包括实验程序、逻辑及相应的研究成果。最后,对今后我国听障者语音编码的研究进行了展望。     

应激性抑郁样行为发生中海马5-羟色胺1A受体的作用及其对NMDA受体和AMPA受体的调节

为探讨慢性不可预见性温和应激(chronic unpredictable mild stress, CUMS)诱发抑郁样行为发生中海马5-羟色胺1A受体(5-hydroxytryptamine receptor 1A, 5-HT1AR)表达与作用, 及其对谷氨酸N-甲基-D-天冬氨酸(N-methyl-D-aspartic acid, NMDA)受体和α-氨基羟甲基异恶唑丙酸(α-amino-3-hydroxy-5- methylisoxazole-4-propionic acid, AMPA)受体的影响。通过建立CUMS动物模型, 给应激抑郁模型大鼠海马微量注射5-HT1A受体激动剂、给正常大鼠海马微量注射5-HT1A受体拮抗剂, 测量大鼠体重变化率, 并采用糖水偏爱测试、旷场实验和悬尾实验等方法对大鼠进行行为学检测, 运用Western blot和ELISA方法检测大鼠海马组织中5-HT1AR和NMDAR和AMPAR的关键亚基的表达以及磷酸化水平。结果显示, 与对照组相比, CUMS组大鼠表现出抑郁样行为, 海马5-HT1AR、AMPA受体的GluR2/3亚基表达及磷酸化明显降低, NMDA受体的NR1和NR2B亚基表达及磷酸化显著增加; 正常大鼠海马微量注射5-HT1A受体拮抗剂WAY100635, 动物行为学表现及AMPA受体、NMDA受体表达及磷酸化水平均与CUMS组相同; 注射5-HT1A受体激动剂8-OH-DPAT能逆转应激诱导的上述改变。以上结果表明, CUMS诱发抑郁样行为与海马5-HT1AR表达下降, AMPAR表达量及磷酸化水平降低, NMDAR表达量及磷酸化水平升高有关。5-HT通过5-HT1AR产生抗抑郁作用。5-HT1AR激动剂抗抑郁作用与降低NMDAR表达量及磷酸化水平, 提高AMPAR表达量及磷酸化水平密切相关。     

Audiotactile multisensory interactions in human information processing

Abstract:  The last few years has seen a very rapid growth of interest in how signals from different sensory modalities are integrated in the brain to form the unified percepts that fill our daily lives. Research on multisensory interactions between vision, touch, and proprioception has revealed the existence of multisensory spatial representations that code the location of external events relative to our own bodies. In this review, we highlight recent converging evidence from both human and animal studies that has revealed that spatially-modulated multisensory interactions also occur between hearing and touch, especially in the space immediately surrounding the head. These spatial audiotactile interactions for stimuli presented close to the head can affect not only the spatial aspects of perception, but also various other non-spatial aspects of audiotactile information processing. Finally, we highlight some of the most important questions for future research in this area.     

轻度认知功能障碍患者工作记忆中 脑电能量及皮质联络功能的变化特征

探讨轻度认知功能障碍患者（MCI）工作记忆状态下脑电能量及皮质联络功能的变化特征。被试为从社区选取的35名轻度认知功能障碍患者和34名健康志愿者。采用简单计算回忆方法,结果发现工作记忆加工过程中会引起4.0~18.0Hz范围内功率值的改变,且MCI组高于正常对照组;MCI患者在中央、顶、颞叶的半球间相干系数均显著高于正常对照组。研究结果提示MCI患者可能存在中央、顶、颞叶皮层的功能减退,工作记忆状态下通过代偿机制仍能维持加工的有效性     

轻度认知损伤的语义记忆研究述评

轻度认知损伤（Mild cognitive impairment,MCI）是介于正常老化与痴呆之间的过渡阶段,表现为与年龄和教育程度不相称的认知功能减退。本文回顾了近期有关MCI语义记忆的研究,分析比较了各研究的实验任务及结果,得出MCI患者存在一定程度的由多种原因造成的语义记忆损伤,语义记忆测验对MCI的早期筛查和转归预测有重要作用。最后指出将来的研究需要将包括语义记忆成分在内的多种认知测验相结合,以便及早发现有可能发展为痴呆的危险个体并开展相应干预。     

老年人记忆补偿的长期稳定性和变异性：来自维多利亚纵向研究的证据

两种记忆状况组来自于参与加拿大维多利亚纵向研究(VLS)的老年人原样本。一种是未受损伤的控制组(NIC), 另一种是轻度记忆损伤组(MMD)。在基线水平和纵向水平上(即5次追踪或12年)比较了他们在日常生活中对记忆补偿技术的使用。我们使用多水平模型(以年龄和教育水平为协变量)来检验基线水平的差异和长期的变化模式。基线的结果表明MMD组被试报告了近期在日常生活中使用记忆补偿策略方面有更大的增长。纵向的结果表明记忆补偿的使用在12年中具有明显的稳定性, 但是与努力相关的补偿机制存在显著组间差异。教育水平这一协变量(可认为是潜在的认知储备指标)和三种记忆补偿策略随时间的不同变化相关。     

The Signal-Cognition interface: Interactions between degraded auditory signals and cognitive processes

A hearing loss leads to problems with speech perception; this is exacerbated when competing noise is present. The speech signal is recognized by the cognitive system of the listener; noise and distortion tax the cognitive system when interpreting it. The auditory system must interact with the cognitive system for optimal signal decoding. This article discusses this interaction between the signal and cognitive system based on two models: an auditory model describing signal transmission and degeneration due to a hearing loss and a cognitive model for Ease of Language Understanding. The signal distortion depends on the specifics of the hearing impairment and thus differently distorted signals can affect the cognitive system in different ways. Consequently, the severity of a hearing loss may not only depend on the lesion itself but also on the cognitive recourses required to interpret the signal.     

Cognition and hearing aids

The perceptual information transmitted from a damaged cochlea to the brain is more poorly specified than information from an intact cochlea and requires more processing in working memory before language content can be decoded. In addition to making sounds audible, current hearing aids include several technologies that are intended to facilitate language understanding for persons with hearing impairment in challenging listening situations. These include directional microphones, noise reduction, and fast-acting amplitude compression systems. However, the processed signal itself may challenge listening to the extent that with specific types of technology, and in certain listening situations, individual differences in cognitive processing resources may determine listening success. Here, current and developing digital hearing aid signal processing schemes are reviewed in the light of individual working memory (WM) differences. It is argued that signal processing designed to improve speech understanding may have both positive and negative consequences, and that these may depend on individual WM capacity.     

Cognition and aided speech recognition in noise: Specific role for cognitive factors following nine-week experience with adjusted compression settings in hearing aids

The working memory model for Ease of Language Understanding (ELU) proposes that language understanding under taxing conditions is related to explicit cognitive capacity. We refer to this as the mismatch hypothesis, since phonological representations based on the processing of speech under established conditions may not be accessed so readily when input conditions change and a match becomes problematic. Then, cognitive capacity requirements may differ from those used for processing speech hitherto. In the present study, we tested this hypothesis by investigating the relationship between aided speech recognition in noise and cognitive capacity in experienced hearing aid users when there was either a match or mismatch between processed speech input and established phonological representations. The settings in the existing digital hearing aids of the participants were adjusted to one of two different compression settings which processed the speech signal in qualitatively different ways ("fast" or "slow"). Testing took place after a 9-week period of experience with the new setting. Speech recognition was tested under different noise conditions and with match or mismatch (i.e. alternative compression setting) manipulations of the input signal. Individual cognitive capacity was measured using a reading span test and a letter monitoring test. Reading span, a reliable measure of explicit cognitive capacity, predicted speech recognition performance under mismatch conditions when processed input was incongruent with recently established phonological representations, due to the specific hearing aid setting. Cognitive measures were not main predictors of performance under match conditions. These findings are in line with the ELU model.