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811.
Drugs modulating gamma-aminobutyric acid (GABA) transmission via the benzodiazepine (BZ) site on the gamma-aminobutyric acid type A (GABAA) receptor have been in widespread use for more than 40 years to treat anxiety, epilepsy, and sleep disorders. These drugs have been shown to be safe, well tolerated, and effective although the mechanism by they produce a myriad of pharmacologic effects remains elusive. In recent years it has been discovered that, although the GABAA receptor is widely distributed in the brain, the substructure and composition of the receptor differs from between brain regions. Termed "GABAA receptor subtypes" their discovery leads to speculation that different subtypes may mediate specific effects of BZs such as anxiety or sedation. The phenotypic analysis of transgenic knock-in and knock-out mice in which particular GABAA receptors were rendered insensitive to the effects of BZ while others were unaffected confirmed this speculation. Subsequently, subtype-specific GABAA ligands were developed that, for example, retained the anxiolytic effects of BZs but were devoid of their sedative effects. Therefore, it may be possible to develop effective anxiolytic compounds that have a much reduced side-effect profile compared with existing drugs. 相似文献
812.
Williams JK Else 'R Hishinuma ES Goebert DA Chang JY Andrade NN Nishimura ST 《Cultural diversity & ethnic minority psychology》2005,11(1):41-56
A confirmatory model integrating Japanese ethnicity, cultural identity, and depression was developed (N = 140). The model incorporated the Center for Epidemiologic Studies-Depression Scale (CES-D), Major Life Events Scale, and Japanese Cultural Scale. Japanese American adolescents scored higher on the Japanese Cultural Scale and reported fewer depressive symptoms on the CES-D total and on 2 of the 3 CES-D factors than part-Japanese American adolescents. Predictors for depression were being Japanese American vs. part-Japanese American, female gender, and culturally intensified events. A significant interaction of behavior by self-identification was noted. The model had good overall fit and suggested that the formation of cultural identity may contribute to depressive symptoms experienced by adolescents, particularly adolescents of mixed heritage. 相似文献
813.
Following Brooks and Vokey (1991), we show that positive transfer to new items generated from an artificial grammar in which the vocabulary has been changed from training to test can be based on "abstract analogy" to specific training items (specific similarity) rather than abstraction of a grammar and symbol remapping rules, even with remapping unique to each test item. The results confirm that transcendence over symbols provides no support for the implicit learning of abstract structure. Ironically, they also show that the effect of specific similarity does not depend on surface characteristics of the items, but the residual effect of grammaticality does. 相似文献
814.
Von Economo neurons (VENs) are a recently evolved cell type which may be involved in the fast intuitive assessment of complex situations. As such, they could be part of the circuitry supporting human social networks. We propose that the VENs relay an output of fronto-insular and anterior cingulate cortex to the parts of frontal and temporal cortex associated with theory-of-mind, where fast intuitions are melded with slower, deliberative judgments. The VENs emerge mainly after birth and increase in number until age 4 yrs. We propose that in autism spectrum disorders the VENs fail to develop normally, and that this failure might be partially responsible for the associated social disabilities that result from faulty intuition. 相似文献
815.
Detecting cheaters 总被引:1,自引:0,他引:1
Cosmides L Tooby J Fiddick L Bryant GA 《Trends in cognitive sciences》2005,9(11):505-6; author reply 508-10
816.
After a person has become stuck on a problem, they sometimes achieve a clear and sudden solution through insight--the so-called Aha! experience. Because of its distinctive experience, the origins and characteristics of insight have received considerable attention historically in psychological research. However, despite considerable progress in characterizing insight, the underlying mechanisms remain mysterious. We argue that research on insight could be greatly advanced by supplementing traditional insight research, which depends on a few complex problems, with paradigms common in other domains of cognitive science. We describe a large set of mini-insight problems to which multiple methods can be applied, together with subjective reports to identify insight problem-solving. Behavioral priming and neuroimaging methods are providing evidence about what, where, and how neural activity occurs during insight. Such evidence constrains theories of component processes, and will help to demystify insight. 相似文献
817.
Wager TD Jonides J Smith EE Nichols TE 《Cognitive, affective & behavioral neuroscience》2005,5(2):127-143
Although task switching is often considered one of the fundamental abilities underlying executive functioning and general
intelligence, there is little evidence that switching is a unitary construct and little evidence regarding the relationship
between brain activity and switching performance. We examined individual differences in multiple types of attention shifting
in order to determine whether behavioral performance and fMRI activity are correlated across different types of shifting.
The participants (n=39) switched between objects and attributes both when stimuli were perceptually available (external) and when stimuli were
stored in memory (internal). We found that there were more switchrelated activations in many regions associated with executive
control—including the dorsolateral and medial prefrontal and parietal cortices—when behavioral switch costs were higher (poor
performance). Conversely, activation in the ventromedial prefrontal cortex (VMPFC) and the rostral anterior cingulate was
consistently correlated with good performance, suggesting a general role for these areas in efficient attention shifting.
We discuss these findings in terms of a model of cognitive-emotional interaction in attention shifting, in which reward-related
signals in the VMPFC guide efficient selection of tasks in the lateral prefrontal and parietal cortices. 相似文献
818.
A growing number of studies have supported the use of unidimensional psychometric test instruments administered via the Internet;
however, support for the use of multidimensional scales is weak. The present study compares paper and Internet administrations
of the Multidimensional Health Locus of Control (MHLC) Scale (Wallston & Wallston, 1981). In terms of reliabilities and factor
structures, the Internet data were found to be at least as good as the paper data. MHLC scores were comparable for paper and
Internet administrations, although the Internet sample scored significantly lower on the Powerful Others subscale. Overall,
the results show that administration of the MHLC Scale via the Internet can produce data comparable to that obtained by pen-and-paper
methods. However, it is concluded that generalization of these findings beyond the psychometric test instrument and sampling
procedures used here is not warranted. 相似文献
819.
820.