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91.
Cognitive disruption and altered hippocampus synaptic function in Reelin haploinsufficient mice 总被引:3,自引:0,他引:3
Qiu S Korwek KM Pratt-Davis AR Peters M Bergman MY Weeber EJ 《Neurobiology of learning and memory》2006,85(3):228-242
The heterozygote reeler mouse (HRM) shows many neuroanatomical and biochemical features that are also present in some human cognitive disorders, such as schizophrenia. In the present study, hippocampal dependent plasticity and cognitive function of the HRM were characterized in detail in an attempt to reveal phenotypic functional differences that result from Reelin haploinsufficiency. The HRM and wild type mice show similar levels of overall activity, coordination, thermal nociception, startle responses, and anxiety-like behavior. In addition, both genotypes show similar shock threshold, identical cued freezing behavior and comparable spatial learning in Morris water maze tasks. However, a significant reduction in contextual fear conditioned learning was observed in the HRM. Electrophysiological studies in hippocampal CA1 synapses revealed a plethora of differences between genotypes. The HRM exhibits reduced field excitatory postsynaptic potentials in responses to similar synaptic inputs, lowered paired pulse facilitation ratio and impaired long-term depression and tetanus-induced long-term potentiation (LTP). Also, deficits were detected in LTP elicited by theta burst stimulation or by a whole cell pairing protocol. These physiologic differences could not be accounted for by changes in the overall amount of glutamate receptor subunits. In addition, it was determined that network-driven excitatory and inhibitory activities recorded in CA1 pyramidal neurons showed that the HRM had comparable amplitude and frequency of spontaneous excitatory postsynaptic currents, but a marked reduction in spontaneous inhibitory postsynaptic currents. Thus, the HRM exhibits a specific hippocampal-dependent learning deficit accompanied with a pronounced impairment of hippocampal plasticity and functional inhibitory innervation. 相似文献
92.
The experiments described in the lead articles by Kowalski and Zimiles and by O'Hanlon and Roberson examine factors that lead to color term acquisition. These experiments touch on the debate regarding the relative contributions of language and concepts in word learning. In this reflection, we examine how conclusions concerning the debate depend deeply on the particular task presented to children, and we propose an alternative approach to studying color term acquisition. 相似文献
93.
What is the source of the mutual exclusivity bias whereby infants map novel labels onto novel objects? In an intermodal preferential looking task, we found that novel labels support 10-month-olds’ attention to a novel object over a familiar object. In contrast, familiar labels and a neutral phrase gradually reduced attention to a novel object. Markman (1989, 1990) argued that infants must recall the name of a familiar object to exclude it as the referent of a novel label. We argue that 10-month-olds’ attention is guided by the novelty of objects and labels rather than knowledge of the names for familiar objects. Mutual exclusivity, as a language-specific bias, might emerge from a more general constraint on attention and learning. 相似文献
94.
The current study evaluated the effect of participating in simulated gambling activities on happiness levels of 3 nursing home residents. A 4‐component analysis was used to measure objective responses associated with happiness during baseline, varying durations of engagement in simulated gambling activities, and 2 follow‐up periods. Results indicated that all residents exhibited a higher percentage of happiness levels while engaged in simulated gambling activities compared with baseline. Follow‐up assessment took place 10 min and 30 min following the intervention; no lasting effects were observed. 相似文献
95.
Janne V. Kujala Ulla Richardson Heikki Lyytinen 《Journal of mathematical psychology》2010,54(1):196-207
We present a simple but effective method based on Luce’s choice axiom [Luce, R.D. (1959). Individual choice behavior: A theoretical analysis. New York: John Wiley & Sons] for consistent estimation of the pairwise confusabilities of items in a multiple-choice recognition task with arbitrarily chosen choice-sets. The method combines the exact (non-asymptotic) Bayesian way of assessing uncertainty with the unbiasedness emphasized in the classical frequentist approach.We apply the method to data collected using an adaptive computer game designed for prevention of reading disability. A player’s estimated confusability of phonemes (or more accurately, phoneme-grapheme connections) and larger units of language is visualized in an easily understood way with color cues and explicit indication of the accuracy of the estimates. Visualization of learning-related changes in the player’s performance is considered.The empirical validity of the choice axiom is evaluated using the game data itself. The axiom appears to hold reasonably well although a small systematic violation is observable for the smallest choice-set sizes. 相似文献
96.
Nathaniel Leibowitz 《Journal of mathematical psychology》2010,54(3):338-340
While the exponential learning equation, indicating a gradually diminishing improvement, is one of the standard equations to describe learning, a sigmoid behavior with initially increasing then decreasing improvement has also been suggested. Here we show that the sigmoid behavior is mathematically derived from the standard exponential equation when the independent variable of the equation is restricted to the successful trials alone. It is suggested that for tasks promoting success-based learning, performance is better described by the derived sigmoid curve. 相似文献
97.
This qualitative study, part of a Canadian national study of fathers’ involvement, opened up First Nations and Métis fathering as a new area of inquiry. Conversational interviews with 80 Indigenous fathers illuminated the socio-historical conditions that have shaped Indigenous men’s experiences of learning to be a father and becoming a man in the context of changing gender relationships and the regeneration of circles of care. Indigenous fathers’ experiences unfold in a socio-historical context fraught with difficulties. However, the study findings suggest cultural strengths and sources of resilience unseen in research and community programs driven by Euro-western perspectives. This research can inform efforts to reduce systemic barriers and reconstitute positive father involvement following disrupted intergenerational transmission of fathering in Canada and elsewhere. 相似文献
98.
Stevienna de Saille 《Science as culture》2013,22(1):99-107
AbstractRecently, Welsh and Wynne have argued that policy efforts to include ‘the public’ in dialogue about technoscience have been accompanied by a simultaneous rise in control over uninvited publics, particularly protestors. Research with a group of knowledge-based activists in the UK suggests a further category between invited and uninvited. The concept of an ‘unruly public’ functions within the sociotechnical imaginary to disinvite those whose response is unwanted or unpredictable, while still appearing to be engaging with ‘the public’ as a whole. Listening to the unexpected questions of the unruly public may in fact support, rather than hinder, efforts to incorporate social concerns into frameworks for responsible innovation at both national and European levels. 相似文献
99.
ABSTRACTEngaging publics in participatory events has become a central means to introducing lay people's voices into processes of technoscientific innovation and governance. However, little attention has been paid to the role of aesthetics, especially in terms of opening up potential ways of critically and creatively engaging with technoscientific matters of concern. The terms semblamatic and matters of potentially are proposed as addressing this dimension of aesthetics. Drawing on practice-based design research, a probe workshop with members of energy communities was implemented. Three probe exercises served to open up potential re-articulations of such core themes as energy, communities and futures. Our goals were to examine the whether such probes enabled semblamatic responses and the emergence of matters of potentiality. Findings were mixed. The continued retention of standard meanings of these core themes suggested that such events can be anaesthetic, blunting access to the semblamatic aspects of engagement. Conversely, there was some opening up in which the core themes were creatively re-articulated. The present perspective, with its three novel terms - semblamatic, matters of potentiality, and anaesthetic - might prove useful in alerting scholars to the complex role of aesthetics in the methodological and analytic practices entailed in engagement with publics. 相似文献
100.
Nowadays, the criticism of the so-called ‘deficit model’ and the need for ‘upstream engagement’ in science and technology are becoming part of the master narratives of public policies in many countries, especially concerning nanotechnology. This may be considered as a major success for STS scholars, whose research results have largely contributed to this change, especially those concerning the GMO controversies. Some STS scholars thus move from a position of distant and critical observers to the role of experts in social engineering or advisers of policy-makers. However, in their enthusiasm concerning the expected benefits of upstream engagement, institutions, TA practitioners and social scientists seem to ignore some important limitations as well as the implicit framing assumptions of the concept. Based on an experience made by a group of social scientists in the Grenoble area—one of the major ‘nanodistricts’ in Europe—our paper shows that the ‘upstream engagement’ concept is still embedded in a linear model of innovation and is not very useful to anyone pursuing the co-production of innovations. It is especially true when socio-technical networks are already aligned by powerful actors and a worldwide agenda as in the case of nanotechnology. In order to give an opportunity for public engagement to have a larger impact on decision-making, we propose an alternative approach, which combines Actor–Network Theory (ANT), as an analytical tool, with the reflexive and ongoing implementation of public participation. Public engagement is probably one of the critical loci where STS scholars must reflect on the articulation between the knowledge they produce and public policies in action. 相似文献