Prosopagnosia and visual object agnosia: A behavioral study

A left-handed woman developed visual object agnosia, prosopagnosia, and visual disorientation after resection of the right occipital lobe. Color agnosia and alexia were absent. When asked to identify objects presented visually, the patient's errors represented visually related objects (underspecifications) or perseverations. Identification was facilitated when she observed the object being used in a natural way. Identification was impaired by surrounding the object with unrelated objects, decreasing the background illumination, decreasing the duration of exposure of the object to the patient, and probably also by decreasing the visual angle subtended by the object. In addition, there were disturbances of visualization (i.e., imaging in the absence of a visual stimulus) that paralleled the perceptual difficulties. We conclude that: (1) A deficit in visual perception, characterized by insufficient feature analysis of visual stimuli, was the basis of the visual agnosia in this case. (2) The visual agnosia could not be explained by (a) a vision-language disconnection syndrome, (b) decay of visual memory traces, or (c) deficiencies in the visual fields (pathologic Funktionswandel). (3) The ability to visualize (visual imagery) probably utilizes some of the same neural pathways used in perception. (4) The results in this case probably can be generalized to some but not all cases of visual agnosia; in particular, the deficit in most previously reported patients with prosopagnosia is similar to that of our case. However, agnosic alexia and color agnosia usually have a different neuropsychological basis.     

睡眠学习的ERP研究

夜间用脑电监测被试睡眠状态,并反复播放英语单词和中文对译词,第二天用词汇决定任务检查学习效果,并记录ERP,结果发现：（1）与未学过的英—中词对相比,被试对学过的词对中中文词的反应时明显缩短;（2）学过的词对中中文词引发的N600的波幅比未学过的明显降低。以上结果表明睡眠学习效果在内隐记忆测验中明显。另外发现被试几乎不能在播放学过的英语词时说出中文对译词,与未学过的词对相比没有显著差别,提示睡眠学习效果在外显记忆测验中不明显。以上结果表明,在本实验条件下,间接测验比直接测验更敏感。     

汉字模糊度、字频和语义启动在N400上的交互作用：N400的IA模型的证据

通过两个实验, 采用事件相关电位技术, 记录大学生被试在同一字判断任务中的脑电波形。两个实验涉及三个因素, 包括模糊度、字频和语义, 语义和字频为被试内设计, 以启动字-靶字(模糊)-探测字的呈现序列为一个测试(trial), 要求被试判断靶字和探测字是否是同一个字。两个实验除了靶字的模糊度不同外, 其他材料完全相同。结果发现, 实验1字频和语义启动间存在交互作用, 其中低频条件下无语义启动比语义启动的N400波幅更偏负, 高频条件则无这种差异; 实验2中只存在语义启动效应, 字频与语义启动间不存在交互作用; 综合两个实验的ERP结果, 模糊度、字频和语义启动三者间存在交互作用, 且高频而非低频条件下模糊度与语义间也有交互作用, 无启动条件下字频和模糊度间也存在交互作用。本研究因此支持N400的IA模型(交互激活模型), 不支持核证模型和词汇后加工理论。     

视觉空间注意研究中的N2pc成分述评

N2pc与空间选择性注意密切相关, 反映了一种对当前任务相关刺激的注意分配过程。N2pc自我特性的研究主要涉及理论解释、测量方法、源定位以及影响因素等方面, 而其实验范式主要有视觉搜索和视觉短时记忆搜索两种范式。以N2pc为指标的研究主要分为与视觉空间注意相关的基础性研究和应用性扩展研究。今后N2pc的研究应该在不断深入细化自身特性研究、做好基础性研究的同时, 更多的向应用性扩展研究拓展。     

The social semantics of Mikhail Pokrovskij and Nikolaj Marr

Criticizing the works of “Western” specialists in semantics, Soviet academician M. M. Pokrovskij (1868–1942) comes to the conclusion that social factors are essential for semantic evolution, while psychological factors constitute an intermediate link between the “external” life of a society and the semantics of the corresponding language. This conception resembles the general explanations of semantic evolution proposed by N. Ja. Marr (1864–1934). Nevertheless, despite a number of common points in the semantic theories of these two researchers, Pokrovskij’s attitude towards Marr was negative: in particular, he disagreed with the thesis of the chronological primacy of Marr’s discoveries in the domain of semantics. The article investigates why Pokrovskij had for a long time constituted an intermediate link between Russian and “Western” “traditions” in the field of semantics.

汉英语言内及语言间重复启动效应的ERP研究

16名母语为汉语的被试参加了一个混合语言的语义判断任务,关键词用汉语和英语呈现,然后重复这些词（语言内或者语言间）。比较词汇第一次呈现、语言内和语言间重复产生的N400波幅的差异发现：汉语和英语的语言内重复启动效应差异不显著,而两种方向的语言间重复启动效应存在不对称性,从英语到汉语的重复启动效应显著大于从汉语到英语的重复启动效应,这与双语表征的非对称模型不尽一致。     

The influence of perceptual and semantic categorization on inhibitory processing as measured by the N2–P3 response

In daily activities, humans must attend and respond to a range of important items and inhibit and not respond to unimportant distractions. Our current understanding of these processes is largely based on perceptually simple stimuli. This study investigates the interaction of conceptual-semantic categorization and inhibitory processing using Event Related Potentials (ERPs). Participants completed three Go–NoGo tasks that increased systematically in the degree of conceptual-semantic information necessary to respond correctly (from single items to categories of objects and animals). Findings indicate that the N2 response reflects inhibitory processing but does not change significantly with task difficulty. The P3 NoGo amplitude, on the other hand, is attenuated by task difficulty. Further, the latency of the peak of the P3 NoGo response elicited by the most difficult task is significantly later than are the peaks detected during performance of the other two tasks. Thus, the level of complexity of conceptual-semantic representations influences inhibitory processing in a systematic way. This inhibition paradigm may be a key for investigating inhibitory dysfunction in patient populations.     

ELECTROPHYSIOLOGICAL CORRELATES OF STIMULUS EQUIVALENCE PROCESSES

Research reported here concerns neural processes relating to stimulus equivalence class formation. In Experiment 1, two types of word pairs were presented successively to normally capable adults. In one type, the words had related usage in English (e.g., uncle, aunt). In the other, the two words were not typically related in their usage (e.g., wrist, corn). For pairs of both types, event‐related cortical potentials were recorded during and immediately after the presentation of the second word. The obtained waveforms differentiated these two types of pairs. For the unrelated pairs, the waveforms were significantly more negative about 400 ms after the second word was presented, thus replicating the “N400” phenomenon of the cognitive neuroscience literature. In addition, there was a strong positive‐tending wave form difference post‐stimulus presentation (peaked at about 500 ms) that also differentiated the unrelated from related stimulus pairs. In Experiment 2, the procedures were extended to study arbitrary stimulus—stimulus relations established via matching‐to‐sample training. Participants were experimentally näive adults. Sample stimuli (Set A) were trigrams, and comparison stimuli (Sets B, C, D, E, and F) were nonrepresentative forms. Behavioral tests evaluated potentially emergent equivalence relations (i.e., BD, DF, CE, etc.). All participants exhibited classes consistent with the arbitrary matching training. They were also exposed also to an event‐related potential procedure like that used in Experiment 1. Some received the ERP procedure before equivalence tests and some after. Only those participants who received ERP procedures after equivalence tests exhibited robust N400 differentiation initially. The positivity observed in Experiment 1 was absent for all participants. These results support speculations that equivalence tests may provide contextual support for the formation of equivalence classes including those that emerge gradually during testing.     

文字加工中的正字法家族效应

正字法家族效应是指正字法邻近词越多, 家族越大, 单词识别越快的一种现象。一般使用词汇判断、语义分类任务、快速命名等实验范式研究。影响家族效应的因素有家族词的频率、材料的语言和家族在单词中的位置等。家族效应表现在150~300ms窗口中的早期成分和更大的N400上。家族效应可能与左大脑半球的不同脑区的的语义激活有关, 也可能与中背外侧前额的执行控制功能有关。家族效应的理论模型主要有：多重标准识别模型、交互激活模型和双通路瀑布式模型等。将来的研究可尝试从实验材料和研究方法等方面进行拓展。     

Electrophysiological Evidence of Different Interpretative Strategies in Irony Comprehension

We explore the hypothesis that induction of holistic or analytic strategies influences comprehension and processing of highly contextualized expressions of ordinary language, such as irony. Twenty undergraduate students were asked to categorize as coherent or incoherent a group of sentences. Each sentence completed a previous story, so that they could be ironical, literal or nonsensical endings. Participants were asked to evaluate whether each sentence was coherent or incoherent. Half of them were initially instructed to consider whether the sentences made sense (holistic condition); the other half were instructed to consider whether the sentences were congruent or incongruent (analytic condition). Behavioral responses and Event Related Potentials were registered during the experiment. Both behavioral and electrophysiological results allow clearly distinguishing between the holistic and the analytic strategies. The fact that the same set of stimuli elicits different ERP waveforms, depending on the strategy with which they are analyzed, suggests that different cognitive processes and different areas of the brain are operating in each case.