不同学习方式下习得性长时程突触增强形成的特点

一般认为,突触传递的长时程增强(Long-term potentiation,LTP)可能是学习和记忆的神经基础。我室的系列工作表明,大鼠在条件性行为的建立中,海马齿状回、CA_3、CA_1区均出现LTP样变化,并将之称为习得性LTP(Learning-de-pendent LTP),而且发现每次训练作业后突触效应的增强,经一段时间(4小时)后就     

乳头体和隔区在大鼠条件性味觉痕迹的形成和保存中的作用

本工作是在前一工作的基础上,进一步研究分别电损毁有关回路的乳头体、隔区,对以糖精水为条件刺激。氯化锂腹腔注射引起中毒作为非条件刺激的条件性糖精厌恶痕迹的形成和保存的影响。结果表明,无论是损毁乳头体,或者隔区,对条件性糖精厌恶痕迹的形成和保存均无影响。说明在本实验条件下,这种条件性味觉痕迹的形成与保存,不依赖边缘系统的乳头体、海马、隔区这些回路的参与,这就进一步说明味觉信号的记忆确有其不同于视、听觉信号的记忆的机制的。     

海马CA_3区习得性LTP的进一步探讨

分辨学习中大鼠ＰＰ－ＣＡ_３突触效应有习得性ＬＴＰ产生,进一步观察到ＭＦ－ＣＡ_３及Ｃｏｍｍ－ＣＡ_３也同步地产生习得性ＬＴＰ,表明几种输入突触都产生习得性ＬＴＰ,而ＭＦ－ＣＡ_３突触效应增强的程度则较Ｃｏｍｍ－ＣＡ_３的为大（Ｐ＜０．０１）。海马ＣＡ_３注入印防己毒素能易化ＰＰ－ＣＡ_３突触习得性ＬＴＰ的产生,工作发现一侧海马ＣＡ_３注印防己毒素,易化对侧ＭＦ－ＣＡ_３突触习得性ＬＴＰ的产生,表明两侧海马ＣＡ_３区在其习得性ＬＴＰ的形成上是相互协同的。     

乳头体对海马齿状回习得性长时程突触增强的影响

用高频电脉冲刺激大鼠乳头体（ＭＢ）,可一过性抑制由刺激穿通纤维（ＰＰ）诱发的海马齿状回（ＤＧ）群体锋电位（ＰＳ）。训练作业前先刺激ＭＢ,导致ＤＧ的习得性长时程突触增强（ＬＤＬＴＰ）的形成显著延缓,相应地延缓了条件性饮水反应的建立。电刺激ＭＢ对ＰＰ─ＤＧＰＳ的这种抑制作用在训练所产生的ＰＳ增大达最高水平时显著减弱,刺激ＭＢ对ＬＤＬＴＰ的保持及相应地对条件反应的巩固没有明显影响。结果表明ＭＢ对ＤＧＬＤＬＴＰ的形成有抑制性调制作用。     

在不同感觉的记忆活动中海马作用的探讨

本文旨在探讨在视、听觉与味、嗅觉这些不同感觉的记忆活动中海马的作用。发现电刺激海马显著地阻抑了兔以声音为条件信号的条件性防御反应的建立,但对以气味为条件信号的条件性防御反应的建立则无明显的影响;电损毁海马对大鼠建立以灯光为条件信号的条件性防御反应有明显的障碍作用,可是对建立以甜味为条件信号的条件性味觉厌恶反应却无明显的影响;还有,电损毁海马对大鼠上述的两种条件反应的保持均无明显的影响。这表明海马在不同感觉的记忆活动中其作用是不同的。对味、嗅觉的记忆海马的参与是不重要的,而在视、听觉记忆形成的早期阶段,海马却起着重要的作用。本文对此进行了讨论,并从系统发生及个体发育的角度进行分析,认为存在上述差异是可以理解的。     

Individual Differences in Categorization Gradience As Predicted by Online Processing of Phonetic Cues During Spoken Word Recognition: Evidence From Eye Movements

Recent studies have documented substantial variability among typical listeners in how gradiently they categorize speech sounds, and this variability in categorization gradience may link to how listeners weight different cues in the incoming signal. The present study tested the relationship between categorization gradience and cue weighting across two sets of English contrasts, each varying orthogonally in two acoustic dimensions. Participants performed a four-alternative forced-choice identification task in a visual world paradigm while their eye movements were monitored. We found that (a) greater categorization gradience derived from behavioral identification responses corresponds to larger secondary cue weights derived from eye movements; (b) the relationship between categorization gradience and secondary cue weighting is observed across cues and contrasts, suggesting that categorization gradience may be a consistent within-individual property in speech perception; and (c) listeners who showed greater categorization gradience tend to adopt a buffered processing strategy, especially when cues arrive asynchronously in time.     

Prediction of intrinsic motivation and sports performance using 2 x 2 achievement goal framework

The purpose of this study was to examine the influence of 2 x 2 achievement goals on intrinsic motivation and performance in handball. Participants were 164 high school athletes. All completed the 2 x 2 Achievement Goals Questionnaire for Sport and the Intrinsic Motivation subscale of the Sport Motivation Scale; the coach for each team rated his athletes' overall sports performance. Using simultaneous-regression analyses, mastery-approach goals positively predicted both intrinsic motivation and performance in sports, whereas performance-avoidance goals negatively predicted sports performance. These results suggest that athletes who pursue task mastery and improvement of their competence perform well and enjoy their participation. In contrast, those who focus on avoiding normative incompetence perform poorly.     

社会性线索对内隐和外显元认知监控的影响

本研究以词图匹配材料为学习材料,以“大多数人选择的情况”为社会性线索,通过分析行为表现和眼动指标,探讨了社会性线索对内隐和外显元认知监控的影响。结果显示：（1）第一次信心判断时,外显信心判断显著高估,内隐信心判断较为准确。第二次信心判断时,在线索一致条件下,外显信心判断等级显著高于内隐信心判断。（2）在提供社会性线索阶段和第二次再认阶段,与线索一致条件相比,线索不一致条件下被提示项的注视时间更短,而未提示项的注视时间更长,且个体改变选择的次数显著增多。结果表明：内隐和外显元认知监测存在分离,内隐监测的准确性更高,外显监测受社会性线索的影响更大;而内隐和外显的元认知控制受社会性线索的影响趋同。