Rapid error correction during human arm movements: evidence for central monitoring

Studies were made of rapid error correction movements in eight subjects performing a visually guided tracking task involving flexion-extension movements about the elbow. Subjects were required to minimize reaction times in this two-choice task. Errors in initial movement direction occurred in about 3% of the trials. Error correction times (time from initiation to reversal of movement in incorrect direction) ranged from 30-150 ms. The first sing of correction of the error movement was a suppression of the electromyographic (EMG) activity in the muscle producing the error movement. This suppression started as early as 20-40 ms after the initiation of the error-related EMG activity and as much as 50 ms before any overt sign of limb movement. The correction of the error movement was also accompanied by an increase in the drive to the muscle which moved the arm in the correct direction. This increased activity always occurred after the initiation of the error movement. it is concluded that the first step in the error correction, suppression of drive to the muscle producing the error movement, cannot be based on information from the moving limb. It is thus suggested that this earliest response to the error movement is based on central monitoring of the commands for movement.     

Delayed reinforcement as an indiscriminable contingency in verbal/nonverbal correspondence training

We investigated the programming of generalization and maintenance of correspondence between verbal and nonverbal behavior in a preschool setting. Four children participated in a series of multiple-baseline designs. In Experiment 1, delayed reinforcement of verbal behavior effectively controlled maintenance of correspondence with previously trained responses and also resulted in generalization of correspondence to one untrained response. As the latter effect was limited, Experiment 2 was a further assessment of the effects of delayed reinforcement of generalization of correspondence to untrained responses, and consistent generalization was shown. Experiment 2 also showed that generalization, if lost, could be recovered through use of "booster training," in which the original contingencies were reinstated for a brief period. Experiment 3 provided replications, with two additional children, of the effects of delayed reinforcement on maintenance of correspondence. Results are discussed in terms of using delayed reinforcement as an indiscriminable contingency.     

The efficient assessment of need for cognition

A short form for assessing individual differences in need for cognition is described.     

γ-线对大白鼠学习能力的影响

本文是以大白鼠在三等分迷宫仪中学习防御性条件反应的方法,观察800拉特γ-线对大白鼠学习能力的影响。实验结果表明,大白鼠的学习能力是下降的,其表现为每天学习的正确率低,达到学会标准所需学习次数增加;反应运动时延长;主动躲避反应的出现率降低。 根据受照动物的特点,我们认为:作为判断学习和记忆能力的指标,反应运动时比正确率更好一点。     

学前和初小儿童智能筛查——图片词汇测试法

美国L.M.Dunn 1965年修改发表的皮勃迪图片词汇测试(PeabodyPicture Vocabulary Test简称PPVT)目前仍是美国智力不足协会(AAMD)所介绍的常用智能测试方法之一。本文参考PPVT制订出适合我国城市学前期与小学初期儿童的图片词汇测试;在上海市区进行标准化;制订了智龄量表、智商和百分位数量表。本测试再测信度r=0.945,二测试者间信度r=0.913。奇偶信度r=0.945,测试标准误σ=4.5。本方法与“学前儿童能力筛查五十项”,“画人试验”,“WPPSI”总智商、语言智商、操作智商,语文成绩,算术成绩的效度相关分别为:r=0.478,r=0.466,r=0.590,r=0.531,r=0.427,r=0.652,r=0.609。本测试制订以来已经数千人次应用,证明是一种简便易行,省时经济,准确性较好,且能进行集体测试的学前及小学初期儿童一般智能(generalintelligence)的筛查方法(Screening test)。     

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。     

社会应激对成年后进行群体隔离的大白鼠的行为的影响

本文观察了在成年后进行群体隔离的大白鼠与群居鼠在摄食、饮水、睡眠等方面的行为差异。着重观察了社会应激对成年后进行群体隔离的动物的行为的影响,以研究群体隔离时动物的年龄与过去生活经验是不是动物在社会应激时发生的行为改变的关键因素。 结果表明:群居与隔离两种环境对动物摄食、饮水和体重无明显影响,但隔离动物睡眠时间较群居动物短。即使在成年后进行群体隔离、社会应激对隔离动物的摄食、饮水、睡眠和攻击性行为的影响也比群居组明显。但进行群体隔离时动物的年龄和隔离前有较长时间的群居生活经验可大大减轻社会应激时行为反应的强度,也可使适应过程发生得快些。这说明早期环境和过去生活经验的重要性。社会应激影响饮水和摄食的方式随年龄而改变,年龄较大的群居鼠对社会应激的适应可能比年龄较轻的群居鼠差。