Instability, Modus ponens and uncertainty of deduction

Considering the instability of nonlinear dynamics, the deductive inference rule Modus ponens itself is not enough to guarantee the validity of reasoning sequences in the real physical world, and similar results cannot necessarily be obtained from similar causes. Some kind of stability hypothesis should be added in order to draw meaningful conclusions. Hence, the uncertainty of deductive inference appears to be like that of inductive inference, and the asymmetry between deduction and induction becomes unrecognizable such as to undermine the basis for the fundamental cleavage between analytic truth and synthetic truth, as W. V. O. Quine pointed out. Induction is not inferior to deduction from a pragmatic point of view.     

情绪的神经心理学理论概述

本文主要论述了情绪神经心理学的有关理论。过去,人们认为情绪和认知分别由皮层下和皮层结构所控制,认知系统控制着情绪系统。现在,人们认为认知和情绪两个机能系统是相互联系的。情绪系统能快速、自动地加工有限数量的信息,认知系统则能有意识和有控制地分析信息。情绪是一个非同质的、多成分的、有等级组织的适应系统。大脑左、右半球在情绪表征和控制中具有不对称性,右半球主要控制自动的、自发的情绪,而左半球在概念水平上调节控制情绪。     

Primal seduction, matricial space and asymmetry in the psychoanalytic encounter

Wishing to highlight the asymmetric dimension that characterizes ethics as 'responsibility toward the other' in Levinas's philosophy, the author presents as an introduction three related concepts of Levinas's thinking: the caress, the face, the saying. Following some poetic narrative reflections offered as 'interlude' moments, the author seeks to bring together her concept of 'matricial space' inspired by Levinas's conception of ethics and the Laplanchian concept of 'primal seduction', both based on asymmetry. She suggests adding to Laplanche's proposition of two kinds of transference (filled-in transference and hollowed-out transference) a third kind: the matricial-space transference. She argues that together with the hollowed-out transference, which is related to the primal seduction, the matricial-space transference, which relates to the matricial position in the parent/analyst, is provoked by the analyst. If the hollowed-out transference assures the moving-on of the analysis, the matricial-space transference, in combination with the hollowed-out transference, is prerequisite for transformation to occur and may be deciphered specifically in 'impasse' situations, at what she coined 'subjectal moments'. As a conclusion, while insisting on the need for asymmetry in the analytic encounter, she suggests the existence in the human neonate of a need for ethics, and she questions the origin of the human capacity to be responsible toward the other. She illustrates her argument using clinical material from her own work alongside that of other authors.     

The role of spatial configuration in tests of working memory explored with functional neuroimaging

While the importance of the prefrontal cortex for "higher-order" cognitive functions is largely undisputed, no consensus has been reached regarding the fractionation of functions within this region. Several recent functional neuroimaging studies have suggested that the mid-ventrolateral frontal cortex may play an important role in various aspects of human memory. Thus, similar patterns of activation have been observed in this region during analogous spatial, verbal and visual span tasks. In the present study, however, activation was observed in a more dorsolateral region of the lateral frontal cortex during a modified version of the spatial span task, which differed only in the spatial configuration of the array employed. The results of a supplementary behavioral study, designed to investigate this effect further, suggest that in spatial memory tasks certain stimulus configurations may encourage subjects to adopt mnemonic strategies, which may depend upon dorsolateral, rather than ventrolateral, regions of the frontal cortex. These findings shed further light on the functional relationship between dorsal and ventral regions of the lateral frontal cortex and, more specifically, how the "executive" processes assumed to be dependent upon these regions might contribute to aspects of human memory.     

Flexible contrast gain control in the right hemisphere

This study investigates whether the right hemisphere has more flexible contrast gain control settings for the identification of spatial frequency. Right-handed participants identified 1 and 9 cycles per degree sinusoidal gratings presented either to the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH). When luminance contrast was randomized across a wide range (20-60%), performance gradually improved with contrast in the LVF-RH. Conversely, performance in the RVF-LH was disrupted and saturated for 20 and 60% of contrast, respectively, leading to a LVF-RH advantage for these contrast levels. When contrast was blocked or randomized for a smaller range (30-50%), the LVF-RH advantage was diminished. Flexible contrast gain control is needed when contrast is randomized across a wide range, but not when it is blocked or randomized across a smaller range. The results therefore suggest that the right hemisphere is able to process spatial frequency information across a wider range of contrast levels than is the left hemisphere.     

The bilateral effect: callosal inhibition or intrahemispheric competition?

The magnification of visual field asymmetry observed with bilateral compared to unilateral tachistoscopic presentation of homologous stimuli (bilateral effect) can be explained by two hypothetical processes: homologous activation with subsequent inhibition of callosal information transfer or intrahemispheric competition for processing resources. A lexical decision task with unilateral and bilateral stimulation and response with the right or left hand was used in an attempt to decide between these hypotheses. Analysis of response time data revealed a bilateral effect, superimposed on a right visual field advantage, and no interaction between visual field and response hand. Results are consistent with the hypothesis of intrahemispheric competition in the left hemisphere.     

Dichotic listening and sleep deprivation: vigilance effects

Twelve sleep-deprived and 13 non-deprived Navy cadets were tested with the dichotic listening procedure for effects of sleep deprivation on hemispheric asymmetry and sustained attention. Consonant-vowel syllables were presented to the subjects in three different conditions, a divided (non-forced) attention condition, a forced right ear and a forced left ear attention condition. In the two forced attention conditions the subjects were instructed to focus attention only on the right or left ear stimulus. The results showed an expected right ear advantage for both groups during the non-forced and forced right attention conditions, indicating superior left hemisphere processing. During the forced left attention condition, the sleep-deprived subjects showed no ear advantage at all, while the non-deprived subjects showed an expected left ear advantage. The results are discussed within a theoretical framework of a dual process model, where sleep deprivation disrupts the ability to sustain attention, caused by a temporary failure of the right hemisphere's top-down (instruction-driven) processing to override the left hemisphere's bottom-up (stimulus-driven) processing.     

Time course of brain activation during graphemic/phonologic processing in reading: an ERP study

The present study sought to investigate the time course of brain activation during grapheme-to-phoneme conversion and phonologic processing of legal Italian syllables. To this goal, we monitored a group of right-handed native Italian volunteers performing a phonologic decision task (same/different judgments). ERPs were recorded from 28 scalp sites during silent reading. Analysis of ERP latency showed faster responses to same syllables than to different ones as early as 105 ms at left temporal electrode site and 160 ms at frontal sites. The first effect of phonologic/graphemic incongruity on the amplitude of ERPs was observed at lateral occipital/posterior temporal sites (N185), where physiologic responses were enhanced to incongruous syllables.     

Ear advantage and consonance of dichotic pitch intervals in absolute-pitch possessors

Left-right asymmetry in the central processing of musical consonance was investigated by dichotic listening tasks. Two piano tones paired at various pitch intervals (1-11 semitones) were presented one note in each ear to twenty absolute-pitch possessors. As a result, a weak overall trend for left ear advantage (LEA) was found, as is characteristic of trained musicians. Second, pitches of dissonant intervals were more difficult to identify than those of consonant intervals. Finally, the LEA was greater with dissonant intervals than with consonant intervals. As the tones were dichotically presented, the results indicated that the central auditory system could distinguish between consonant and dissonant intervals without initial processing of pitch-pitch relations in the cochlea.     

Neuropsychological aspects of facial asymmetry during emotional expression: A review of the normal adult literature

This review focuses on facial asymmetries during emotional expression. Facial asymmetry is defined as the expression intensity or muscular involvement on one side of the face (“hemiface”) relative to the other side and has been used as a behavioral index of hemispheric specialization for facial emotional expression. This paper presents a history of the neuropsychological study of facial asymmetry, originating with Darwin. Both quantitative and qualitative aspects of asymmetry are addressed. Next, neuroanatomical bases for facial expression are elucidated, separately for posed/voluntary and spontaneous/involuntary elicitation conditions. This is followed by a comprehensive review of 49 experiments of facial asymmetry in the adult literature, oriented around emotional valence (pleasantness/unpleasantness), elicitation condition, facial part, social display rules, and demographic factors. Results of this review indicate that the left hemiface is more involved than the right hemiface in the expression of facial emotion. From a neuropsychological perspective, these findings implicate the right cerebral hemisphere as dominant for the facial expression of emotion. In spite of the compelling evidence for right-hemispheric specialization, some data point to the possibility of differential hemispheric involvement as a function of emotional valence. An earlier version of this paper by the first author was presented at the XV Annual Symposium of the Society of Craniofacial Genetics, July 12, 1992, Stanford University, Palo Alto, CA.