Spinal Cord Circuits

Over the past decade, research at three different levels of sensorimotor control has revealed a degree of complexity that challenges traditional hypotheses regarding servocontrol of individual muscles: (a) The connectivity of spinal circuits is much more divergent and convergent than expected. (b) The normal and reflex-induced recruitment of individual muscles and compartments of muscles is more finely controlled than was noted previously. (c) The mechanical interactions among linked skeletal segments and their often multiarticular muscles are neither simple nor intuitively obvious. We have developed a mathematical model of the cat hind limb that permits us to examine the influence of individual muscles on posture and gait. We have used linear quadratic control theory to predict the optimal distribution of feedback from a hypothetical set of proprioceptors, given different assumptions about the behavioral goals of the animal. The changes in these predictions that result from changes in the structure and control objectives of the model may provide insights into the functions actually performed by the various circuits in the spinal cord.     

Frontal-Striatal Circuits in Cognitive Aging: Evidence for Caudate Involvement

Changes in cognition with aging have been claimed to be due in large part to a decline in frontal lobe function. However, at our present state of knowledge, the emphasis on the frontal lobes to the exclusion of the rest of the frontal-striatal circuits of which they are a part is unwarranted. To argue this point, I consider another anatomical candidate within these circuits, the caudate. Evidence is presented that the caudate decreases in size with age as much as the frontal lobes and that damage to either the frontal lobes or the caudate is accompanied by declines in inhibitory processes, executive control, and cognitive speed similar to those seen in normal aging. Separating the unique contributions of the frontal lobes and the caudate to these circuits is difficult but should be the focus of future studies of the biological basis of cognitive aging.     

基因多态性对情绪调节神经回路的影响

随着脑成像和基因分析等新技术手段的综合运用, 情绪调节的神经生物学基础研究有了很大进展。综述相关研究表明: 情绪调节的神经回路涉及背侧-腹侧前额叶、前额叶-杏仁核和皮层-边缘系统的相互作用, 这些神经回路受到5-羟色胺传运体(5-hydroxytryptamine transporter, 5-HTT)、儿茶酚转甲酶 (Catechol-O-methyltransferase, COMT)和色氨酸羟化酶2(Tryptophan hydroxylase 2, TPH2)等基因变异, 以及不同基因多态之间交互作用的影响。情绪调节神经回路的功能出现障碍将导致情绪疾病的产生。     

情景变换诱发已消退恐惧记忆重现的神经环路

暴露疗法是治疗创伤后应激障碍的主要行为疗法。当被试反复暴露于可引起恐惧反应的条件刺激(如白噪音), 但却不伴有非条件刺激(如足底电击)时, 恐惧记忆将被消退, 形成消退记忆。但恐惧记忆并未从根本上被擦除, 当被试在消退训练以外的情景暴露于条件刺激时, 已消退的恐惧记忆将会重现。海马、内侧前额叶皮层、杏仁核等脑区及其相互连接的神经环路是情景诱发恐惧记忆重现的生理基础。情景变化诱发恐惧记忆重现过程中, 海马可能是通过直接投射至杏仁核基底核、杏仁核外侧核或通过边缘前皮质间接调控杏仁核基底核、杏仁核外侧核的功能, 产生恐惧反应。     

Circuits and circumstances: the neurobiological consequences of early relationship experiences and how they shape later behaviour

The last decade has seen a vast increase in knowledge of how the human brain develops. It has been demonstrated that both the establishment of synaptic connections between neurones and the programming of neurochemical responses that have an effect on the whole body are dependent on experience. The most sensitive period for brain growth, the time of optimal plasticity, is over the first two or three years of life. If the baby's neurological development is threatened by abuse or neglect, which includes excessive attachment disruption, the damage may set its stamp on the rest of life.     

Underlying Circuits of Social Support for Bullied Victims: An Appraisal‐Based Perspective on Supportive Communication and Postbullying Adjustment

This study examined the working mechanisms of social support for victims of bullying. Structural equation modeling analyses based on retrospective survey data (N = 448) revealed that the effects of supportive messages varied distinctively, depending on the content of the messages; emotional and esteem support enhanced, but network support impeded, positive reappraisal (the effects of informational support were not significant). Except for that which was related to network support, discrepancy between desired and received support was associated with less positive appraisal. Finally, positive appraisal was found to enhance victims' postbullying adjustment both behaviorally and psychologically. These findings are discussed in terms of their theoretical and practical implications with reference to the literature on social support and coping of bullied victims.     

Increase in Syntaxin 1B mRNA in Hippocampal and Cortical Circuits During Spatial Learning Reflects a Mechanism of Trans-synaptic Plasticity Involved in Establishing a Memory Trace

It has long been proposed that the cellular and molecular mechanisms responsible for LTP may well involve the mechanisms that lead to the type of synaptic modification that occurs during learning. However, it is also known that a single memory trace is encoded in spatially distributed networks; implying that alterations of synaptic strength occur at multiple sites along circuits of connected cells. Recent evidence suggests that regulation of the gene encoding syntaxin 1B, a presynaptic protein involved in exocytosis, plays an important role in the mediation of trans-synaptic LTP, a candidate mechanism for the propagation of plasticity in neural circuits during learning. Using in situ hybridization to measure the mRNA levels at different time points after learning a spatial working or reference memory task, we show that expression of the gene encoding this protein in the hippocampal and corticoprefrontal circuits increases linearly with performance at a critical window of learning when rats are reaching between 75% and 100% of their maximal performance. No changes were observed during the early phases of learning or when rats where overtrained. The correlational analysis indicates that coordinated increases in syntaxin 1B expression occurs in hippocampal circuits during working memory and in more widespread hippocampocortical circuits during reference memory. These results suggest that a form of trans-synaptic plasticity mediated in part by regulation of the expression of syntaxin 1B may play an active role in configuring specific spatially distributed circuits during the laying down of memories.     

当代中国的社会转型

本文以我国社会生活发生的广泛而深刻的变化为背景,深入揭示了这种变化深层的社会转型。这种转型就是：由权力社会走向能力社会;由人治社会走向法治社会;由人情社会走向理性社会;由依附社会走向自立社会;由身份社会走向实力社会;由注重先天给定社会走向注重后天努力社会;由一元化社会走向多样化社会;由人的依赖社会走向物的依赖社会;由静态社会走向流动社会;由“国家”社会走向“市民”社会。     

Cogmic space for narrative-based world representation

Representing a world or a physical/social environment in an agent’s cognitive system is essential for creating human-like artificial intelligence. This study takes a story-centered approach to this issue. In this context, a story refers to an internal representation involving a narrative structure, which is assumed to be a common form of organizing past, present, future, and fictional events and situations. In the artificial intelligence field, a story or narrative is traditionally treated as a symbolic representation. However, a symbolic story representation is limited in its representational power to construct a rich world. For example, a symbolic story representation is unfit to handle the sensory/bodily dimension of a world. In search of a computational theory for narrative-based world representation, this study proposes the conceptual framework of a Cogmic Space for a comic strip-like representation of a world. In the proposed framework, a story is positioned as a mid-level representation, in which the conceptual and sensory/bodily dimensions of a world are unified. The events and their background situations that constitute a story are unified into a sequence of panels. Based on this structure, a representation (i.e., a story) and the represented environment are connected via an isomorphism of their temporal, spatial, and relational structures. Furthermore, the framework of a Cogmic Space is associated with the generative aspect of representations, which is conceptualized in terms of unconscious- and conscious-level processes/representations. Finally, a proof-of-concept implementation is presented to provide a concrete account of the proposed framework.     

On the a priori and a posteriori assessment of probabilities

We argue that in spite of their apparent dissimilarity, the methodologies employed in the a priori and a posteriori assessment of probabilities can both be justified by appeal to a single principle of inductive reasoning, viz., the principle of symmetry. The difference between these two methodologies consists in the way in which information about the single-trial probabilities in a repeatable chance process is extracted from the constraints imposed by this principle. In the case of a posteriori reasoning, these constraints inform the analysis by fixing an a posteriori determinant of the probabilities, whereas, in the case of a priori reasoning, they imply certain claims which then serve as the basis for subsequent probabilistic deductions. In a given context of inquiry, the particular form which a priori or a posteriori reason may take depends, in large part, on the strength of the underlying symmetry assumed: the stronger the symmetry, the more information can be acquired a priori and the less information about the long-run behavior of the process is needed for an a posteriori assessment of the probabilities. In the context of this framework, frequency-based reasoning emerges as a limiting case of a posteriori reasoning, and reasoning about simple games of chance, as a limiting case of a priori reasoning. Between these two extremes, both a priori and a posteriori reasoning can take a variety of intermediate forms.     

Karen Horney: Theorist in Psychoanalysis and Feminine Psychology

Karen Horney is unique and unparalleled in personality theory. She has the distinction of being the only woman whose theory is detailed in personality textbooks. Horney is known as a neo-Freudian for her revision of Freudian thought; a social psychological theorist for her emphasis on cultural and social influences; a humanist for her holistic view and emphasis on self-realization; and a feminist for her development of a feminine psychology. She was a founder of the Association for the Advancement of Psychoanalysis and founder and dean of the American Institute for Psychoanalysis, a training institute. She was a teacher who could simplify the most difficult concepts; a therapist with deep human involvement; Editor of the American Journal of Psychoanalysis ; a Fellow of the American Psychiatric Association; a regular contributor to scientific sessions; and a prolific writer. She was personally and professionally a "well-rounded balance of an abundance of striving and creative possibility."     

The preference to work for a man or a woman: A matter of sex and gender?

A survey of 455 individuals sampled from two populations that varied in age, educational level, and work experience posed a question asked in Gallup polls over six decades: “If you were taking a new job and had your choice of a boss, would you prefer to work for a man or a woman?” Respondents could state that they would prefer a male boss, prefer a female boss, or had no preference. As expected from theory and Gallup results, respondents who had a preference preferred to work for a man more than a woman, although a majority expressed “no preference.” When they expressed a preference, women preferred to work for a female boss over a male boss more than men did, whereas men preferred to work for a male boss over a female boss more than women did. Sex-typed (i.e., masculine or feminine) respondents in gender identity exhibited a greater preference to work for a boss of a particular sex over having no preference than non-sex-typed respondents. Further, feminine respondents preferred to work for a female boss over a male boss more than masculine respondents did, whereas masculine respondents preferred to work for a male boss over a female boss more than feminine respondents did. Overall, these results suggest that the preference to work for a man or a woman is a matter of both sex and gender. Implications for job applicants' vocational decisions and how female leaders fare in the workplace are discussed.     

Exploring a recognition-induced recognition decrement

Four experiments were performed to explore a recognition decrement that is associated with the recognition of a word from a short list. The stimulus material for demonstrating the phenomenon was a list of words of different syntactic types. A word from the list was recognized less well following a decision that a word of the same type had occurred in the list than following a decision that such a word had not occurred in the list. A recognition decrement did not occur for a word of a given type following a positive recognition decision to a word of a different type. A recognition decrement did not occur when the list consisted exclusively of nouns. It was concluded that the phenomenon may reflect a criterion shift but, probably, does not reflect a list strength effect, suppression, or familiarity attribution consequent to a perceived discrepancy between actual and expected fluency.