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931.
连续和同时线索化条件下的返回抑制容量 总被引:9,自引:1,他引:8
利用线索-靶子模式进行了返回抑制容量的两个实验。实验一对外周数个位置连续线索化,实验二对外周数个位置同时线索化。结果表明:(1)在连续线索化条件下,当线索化位置是相邻时,返回抑制容量可以达到4个,当线索化位置是间隔时,返回抑制容量只有1个。(2)在同时线索化条件下.当线索化位置是相邻时,返回抑制容量可以达到3个,当线索化位置是间隔时.返回抑制容量只有1个。结果支持认为存在着两种不同的返回抑制的观点,即一种是弥散性的,其容量较大;另一种是集中性的,其容量只有一个。 相似文献
932.
儿童角色认同对记叙文记忆与理解影响的研究 总被引:1,自引:0,他引:1
通过考查儿童对不同类型记叙文的记忆与理解的情况,探讨儿童角色认同对记叙文理解与记忆的影响。结果表明。角色认同有助于儿童对记叙文的记忆与理解。而且,这种角色认同是已具备基本书面语言能力的儿童在阅读中自然而然地发生的,提示对认同没有重要的影响。 相似文献
933.
The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni2+ (50 microM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni2+ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 microM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni2+. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni2+. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus. 相似文献
934.
Dong Song Xiaping Xie Zhuo Wang Theodore W. Berger 《Neurobiology of learning and memory》2001,76(3):375
The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni2+ (50 μM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni2+ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 μM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni2+. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni2+. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus. 相似文献
935.
采用间接测量方法分别探讨刻板印象的内隐效应与内一外群体效应。实验结果表明 :( 1)内隐刻板印象是存在的 ,并且在很大程度上是一种无意识内隐影响的表现 ;( 2 )刻板印象是一个自动化的过程 ;( 3)刻板印象表现出强烈的“内一外群体效应” 相似文献
936.
937.
运用眼动分析法探讨了外在特征变化对人像辨认的影响,即外在特征多少、学习与辨认外在特征的一致性对人像辨认的影响。因变量为人像辨认的反应时、辨别力、注视次数、眼跳幅度。实验表明:学习与辨认的一致性对人像辨认影响显著,外在特征多少对人像辨认影响不显著。 相似文献
938.
大量脑科学的研究揭示,应激对与海马相关的陈述性记忆的调节主要通过应激激素,尤其是糖皮质激素的分泌而发生作用,而影响的方向取决于一些调节变量,包括糖皮质激素升高的水平以及记忆的不同阶段等。研究发现基底外侧杏仁核是糖皮质激素对记忆不同阶段产生差异性影响的关键部位。因此,在教育过程中,既要科学地认识应激对记忆的消极影响,又要有效利用应激对记忆产生的调节作用,来提高学生的学习效率。 相似文献
939.
家庭居住与机构居住老年人社会支持的比较研究 总被引:2,自引:0,他引:2
以65位家庭居住和92位机构居住的老年人为样本,采用Sherbourne和Stewart的MOS社会支持问卷和自编社会支持问卷调查了老年人的社会支持现状,比较了家庭居住与机构居住老年人社会支持的不同特点。结果发现:(1)家庭居住和机构居住老年人在社会支持维度上存在显著差异:在心理支持、行为支持、活动支持等维度上,机构居住的老年人显著高于家庭居住的老年人;而在感情支持维度上家庭居住的老年人显著高于机构居住的老年人。(2)社会支持对老年人的身心健康具有显著影响。(3)性别,年龄,教育水平,职业状况,婚姻状况,子女数量,健在兄弟姐妹数量等人口统计变量对不同居住背景老年人的社会支持有显著影响。 相似文献
940.