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801.
Self-reported reasons for suicide attempts and nonsuicidal self-injury were examined using the Parasuicide History Interview within a sample of chronically suicidal women meeting criteria for borderline personality disorder (N = 75). Overall, reasons given for suicide attempts differed from reasons for nonsuicidal self-injury. Nonsuicidal acts were more often reported as intended to express anger, punish oneself, generate normal feelings, and distract oneself, whereas suicide attempts were more often reported as intended to make others better off. Almost all participants reported that both types of parasuicide were intended to relieve negative emotions. It is likely that suicidal and nonsuicidal parasuicide have multiple intents and functions.  相似文献   
802.
The rapidity with which infants come to understand language and events in their surroundings has prompted speculation concerning innate knowledge structures that guide language acquisition and object knowledge. Recently, however, evidence has emerged that by 8 months, infants can extract statistical patterns in auditory input that are based on transitional probabilities defining the sequencing of the input's components (Science 274 (1996) 1926). This finding suggests powerful learning mechanisms that are functional in infancy, and raises questions about the domain generality of such mechanisms. We habituated 2-, 5-, and 8-month-old infants to sequences of discrete visual stimuli whose ordering followed a statistically predictable pattern. The infants subsequently viewed the familiar pattern alternating with a novel sequence of identical stimulus components, and exhibited significantly greater interest in the novel sequence at all ages. These results provide support for the likelihood of domain general statistical learning in infancy, and imply that mechanisms designed to detect structure inherent in the environment may play an important role in cognitive development.  相似文献   
803.
The cerebellum is known to have important functions in motor control, coordination, motor learning, and timing. It may have other "higher" functions as well, up to and including cognitive processing independent of motor behavior. In this article, we will review some of the evidence from functional imaging, lesion studies, electrophysiological recordings, and anatomy which support the theory that the cerebellum provides a "forward model" of the motor system. This forward model would be used for control of movement; it could also underlie a cerebellar role in coordination. In this role, the forward model would generate time-specific signals predicting the motion of each motor effector, essential for predictive control of, for example, eye and hand movements. Data are presented from human eye and hand tracking that support this. Tracking performance is better if eye and hand follow the same spatial trajectory, but better still if the eye leads the hand by about 75 to 100 ms. This suggests that information from the ocular control system feeds into the manual control system to assist its tracking.  相似文献   
804.
We examined the factor structure and psychometric properties of the Trusting Relationship Questionnaire, a brief measure of relationship quality between youth and community-based service providers involved in their care. Data on youth residing in Therapeutic Foster Care and in Group Homes (N = 296) were collected. We identified a one-factor solution for the child version of the measure and a two-factor structure for the adult version: child's perception of the relationship and adult's perception of the relationship. Both versions appear to be highly reliable and possess adequate levels of construct, criterion, and discriminative validity. While no statistically significant age differences were noted on the parent version, on the child version, older youth were more likely to report lower relationship scores. Gender differences were found on both versions: Female youth reported higher scores on the child version as did adults reporters of relationships with female youth, but only for the first factor—child's perception of the relationship. Overall, the TRQ appears to capture the quality of the relationship between service providers and youth in their care, thus bridging a gap in assessment measures.  相似文献   
805.
Training-induced and electrically induced potentiation in the neocortex   总被引:3,自引:0,他引:3  
Long-term potentiation (LTP) shares many properties with memory and is currently the most popular laboratory model of memory. Although it has not been proven that memory is based on an LTP-like mechanism, there is evidence that learning a motor skill can induce LTP-like effects. This evidence was obtained in a slice-preparation experiment, which precluded within-animal comparisons before and after training. In the present experiments, Long-Evans rats were unilaterally trained to acquire a forelimb reaching and grasping skill. Evoked potentials were found to be larger in motor cortex layer II/III in the trained, compared to the untrained, hemisphere in slice, acute, and chronic preparations. Consistent with previous research, the trained hemisphere was less amenable to subsequent LTP induction. Furthermore, the application of either LTP- or LTD-inducing stimulation during the training phase of the reaching task disrupted the acquisition of the skill, providing further evidence that memory may be based on an LTP mechanism.  相似文献   
806.
In many regions of the brain, including the mammalian cortex, the strength of synaptic transmission can be bidirectionally regulated by cortical activity (synaptic plasticity). One line of evidence indicates that long-term synaptic potentiation (LTP) and long-term synaptic depression (LTD), correlate with the phosphorylation/dephosphorylation of sites on the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunit protein GluR1. Bidirectional synaptic plasticity can be induced by different frequencies of presynaptic stimulation, but there is considerable evidence indicating that the key variable is calcium influx through postsynaptic N-methyl-d-aspartate (NMDA) receptors. Here, we present a biophysical model of bidirectional synaptic plasticity based on [Ca2+]-dependent phospho/dephosphorylation of the GluR1 subunit of the AMPA receptor. The primary assumption of the model, for which there is wide experimental support, is that the postsynaptic calcium concentration, and consequent activation of calcium-dependent protein kinases and phosphatases, is the trigger for phosphorylation/dephosphorylation at GluR1 and consequent induction of LTP/LTD. We explore several different mathematical approaches, all of them based on mass-action assumptions. First, we use a first order approach, in which transition rates are functions of an activator, in this case calcium. Second, we adopt the Michaelis-Menten approach with different assumptions about the signal transduction cascades, ranging from abstract to more detailed and biologically plausible models. Despite the different assumptions made in each model, in each case, LTD is induced by a moderate increase in postsynaptic calcium and LTP is induced by high Ca2+ concentration.  相似文献   
807.
This essay introduces a thematic issue focused on the contributions to clinical ethics and the philosophy of medicine by Richard M. Zaner. We consider the apparent divorce of Zaners philosophical roots from his recent narrative immersions into the blooming, buzzing confusions of clinical-moral lifeworlds. Our considerations of the Zanerian context and origins of the clinical encounter introduce the fundamental questions faced by Zaner and his commentators in this issue, questions about the role of ethics consultants, moral authority, and clinical truths.  相似文献   
808.
As a confluence of unique values and activities, the collective practice of community psychology is difficult to characterize in a simple way. Increasingly, however, professional contexts are laden with pressure to define any practice—from library work to medical interventions—in the orderly, compact language of traditional science. This trend has historically been resisted in the field by those sensing a fundamental lack of fit between the fluid, emergent aspects of community psychological practice and the fixed, precise language of classic science. In response to this “language–practice gap,” some have attempted to adapt the traditional language of science to better fit the field's practice, while others have explored alternative languages of practice seemingly more indigenous to the messy “swamp” of actual communities. While the former effort leaves some theoretical contradictions intact, the latter tends to discount scientific identity entirely. This paper proposes a potential step forward by resituating questions of disciplinary language and identity within a current philosophical discourse where the nature of social science itself remains sharply contested. This suggests shifting attention away from “should we be a science?” to “what kind of science might we be after all?”; in turn, alternative languages may be re‐cast as legitimate contributors to a kind of science more authentic to human communities—even a viable “science in the swamp.” One such language–philosophical hermeneutics—is presented as a particularly valuable supplement to traditional science. Illustrations highlight ways that hermeneutics may advance the formal language of the field towards a closer fit of what actually happens in practice, while preserving and even bolstering the empirical rigor and scientific identity of the field.  相似文献   
809.
810.
In this study of how the frequency of interaction affects decisions on reward allocation, 320 Chinese adults were randomly assigned to 8 conditions and instructed to read a scenario describing 2 co-workers completing a task and obtaining a bonus. The 8 conditions differed in the type of relationships, the frequency of past interaction between co-workers, and the possibility of future interaction. Each participant was instructed to act as the allocator and to hypothetically allocate a monetary reward to the co-worker. The results indicated that both past interaction and future interaction between the co-workers significantly influenced the allocation decision. These results also suggested that the frequency of 2 individuals' past interaction can be predictive of the closeness of their relationship.  相似文献   
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