Informal versus formal mathematics

We discuss Kunen’s algorithmic implementation of a proof for the Paris–Harrington theorem, and the author’s and da Costa’s proposed “exotic” formulation for the P = NP hypothesis. Out of those two examples we ponder the relation between mathematics within an axiomatic framework, and intuitive or informal mathematics. The author is Visiting Researcher at IEA/USP, Professor of Communications, Emeritus, at the Federal University in Rio de Janeiro, and a full member of the Brazilian Academy of Philosophy.     

论结合CNV和P300进行犯罪心理生理测试的可行性

在国外,事件相关电位技术应用于犯罪心理生理测试已经有多年的历史,近年来我国也有所尝试;但大多是以单一的ERP成分作为判断指标。若在测试过程中能通过特殊的设计,同时诱发两种或两种以上的特异性ERP,在结果分析时采用多种指标进行相互印证、相互支持的分析,定能在一定程度上提高测试的准确性。本文以此为出发点,讨论结合CNV和P300进行犯罪心理生理测试的可行性。     

Hand function,not proximity,biases visuotactile integration later in object processing: An ERP study

Behavioral studies document a functional hand proximity effect: objects near the palm, but not the back of the hand, affect visual processing. Although visuotactile bimodal neurons integrate visual and haptic inputs, their receptive fields in monkey cortex encompass the whole hand, not just the palm. Using ERPs, we investigated whether hand function influenced the topology of integrated space around the hand. In a visual detection paradigm, target and non-target stimuli appeared equidistantly in front or in back of the hand. Equivalent N1 amplitudes were found for both conditions. P3 target versus non-target amplitude differences were greater for palm conditions. Hand proximity biased processing of visual targets equidistant from the hand early in processing. However, hand function biases emerged later when targets were selected for potential action. Thus, early hand proximity effects on object processing depend on sensory-reliant neural responses, whereas later multisensory integration depend more on the hand’s functional expertise.     

Muslim Governance and the Duty to Protect

In this response to Johnson, Oh reaffirms the scholarly vision of Kelsay and Twiss, elaborates upon Muslim perspectives on human rights, and questions the emphasis on violent humanitarian interventions as part of the Responsibility to Protect mandate. Oh suggests that, in light of the historical relationship between Muslim and non‐Muslim states and the aftermath of the second Iraq War, more consideration be given to the rebuilding of Muslim‐majority societies. Oh also highlights the concept of duty as a religiously based ideal to which governments of Muslim nations ought to be held.     

Visual asymmetry revisited: Mind wandering preferentially disrupts processing in the left visual field

An emerging theory proposes that visual attention operates in parallel at two distinct time scales – a shorter one (<1 s) associated with moment-to-moment orienting of selective visuospatial attention, and a longer one (>10 s) associated with more global aspects of attention-to-task. Given their parallel nature, here we examined whether these comparatively slower fluctuations in task-related attention show the same visual field asymmetry – namely, a right visual field bias – as often reported for selective visual–spatial attention. Participants performed a target detection task at fixation while event-related potentials (ERP) time-locked to task-irrelevant visual probes presented in the left and right visual fields were recorded. At random intervals, participants were asked to report whether they were “on-task” or “mind wandering”. Our results demonstrated that sensory attenuation during periods of “mind wandering” relative to “on-task”, as measured by the visual P1 ERP component at electrodes sites contralateral to the stimulus, was only observed for probes presented in the left visual field. In contrast, the magnitude of sensory gain in the right visual field was insensitive to whether participants were “on-task” or “mind wandering”. Taken together, our results support the notion that task-related attention at longer time scales and spatial attention at shorter time scales affect the same underlying mechanism in visual cortex.     

P16、CyclinDl和CDK4在结直肠癌组织中表达及意义

细胞周期过程中癌基因的激活与抑癌基因的失活等是造成细胞恶性增殖、转化的重要因素。细胞周期G1／S期各调节因子的异常改变与细胞癌变关系尤为密切。P16、CyclinDl和CDK4均为重要的细胞周期调控蛋白,任何原因导致这些蛋白异常表达时,将引起细胞周期调节失控,导致肿瘤的发生和恶性演进。结直肠癌的发生发展同上述三者关系密切。本实验通过免疫组化方法进行检测结直肠癌组织中P16、CyclinDl和CDK4三者的表达及其与结直肠癌临床指标的关系,为揭示三者在结直肠癌发生发展中的作用提供一定的实验依据。     

Response-specific slowing in older age revealed through differential stimulus and response effects on P300 latency and reaction time

Older age produces numerous changes in cognitive processes, including slowing in the rate of mental processing speed. There has been controversy over the past three decades about whether this slowing is generalized or process-specific. A growing literature indicates that it is process-specific and suggests it is most dramatic at the interface where a stimulus input is translated into a response output. We tested this hypothesis using a task in which young and older adult males made either compatible or incompatible responses to the word LEFT or RIGHT shown briefly and variously located in a 4 row × 6 column matrix surrounded by # signs or by letters chosen randomly from the sets A-G or A-Z. Processing speed was measured using P300 latency and reaction time. Experimental effects on these two measures provided support for the hypothesis in revealing that stimulus identification processes were preserved, whereas processes related to translating a stimulus input into a designated response output and then selecting that response were compromised in the elderly.     

生命性在句子加工中作用的ERP研究

生命性广泛地渗透到人类语言系统中发挥其作用。本文主要结合最新和经典的有关生命性的ERP研究探讨了生命性信息起作用的模式和时间进程。在句子加工过程中,生命性影响论元的加工并影响题元结构的建构和解释。以往研究表明,生命性违反有时引发的是N400效应,有时引发的是P600效应,少数情况还表现出N400-P600的双相模式。生命性在句子加工中的作用还跟多种变量存在交互作用,语境、题元可逆性、论元之间的语义关系、动词类型和其固有的题元结构都可能影响生命性信息起作用的模式。文章最后进行总结和展望,并提出未来研究仍有必要继续探讨生命性信息加工的时间神经动态性及其在句子加工中的具体作用机制。     

Dissociation between the behavioural and electrophysiological effects of the face and body composite illusions

Several studies have reported similarities between perceptual processes underlying face and body perception, particularly emphasizing the importance of configural processes. Differences between the perception of faces and the perception of bodies were observed by means of a manipulation targeting a specific subtype of configural processing: the composite illusion. The composite face illusion describes the fact that two identical top halves of a face are perceived as being different if they are presented with different bottom parts. This effect disappears, if both halves are laterally shifted. Crucially, the effect of misalignment is not observed for bodies. This study aimed to further explore differences in the time course of face and body perception by using the composite effect. The present results replicated behavioural effects illustrating that misalignment affects the perception of faces but not bodies. Thus, face but not body perception relies on holistic processing. However, differences in the time course of the processing of both stimulus categories emerged at the N170 and P200. The pattern of the behavioural data seemed to be related to the P200. Thus, the present data indicate that holistic processes associated with the effect of misalignment might occur 200 ms after stimulus onset.