Bilateral coordination in human infants: stepping on a split-belt treadmill

A motorized treadmill often elicits locomotor-like alternate stepping in 7-month-old infants who normally perform few, if any, stepping movements. The step cycle duration is a function of the speed of the treadmill. When infants were held so that each leg was on a separate treadmill belt, each of which was driven at a different speed, the overall cycle duration was intermediate between the cycle durations at the fast or slow speeds alone. Infants shortened the stance on the slow belt and increased the stance on the fast belt to maintain regularly alternating steps. Even before voluntary locomotion, both legs acted in a cooperative manner, with the dynamic status of one limb affecting the timespace behavior of the opposite limb.     

6-羟基多巴胺所致旋转行为的动物模型

选用神经毒素(6-OHDA)造成动物大脑黑质纹状体的单侧性损伤,致使动物的大脑两半球机能显示不对称性。致伤后以可卡因诱发动物的旋转行为。 本实验共观察了成年的Holtzman种系雌性大白鼠43只。结果表明,有38例(88.37％)的多巴胺的耗竭率在85一100％,它们的伤情较为理想。但是,3只动物(6.98％)的多巴胺的耗竭率小于60％,2只动物(4.65％)的多巴胺的耗竭率在60—84％。 本文详细地介绍了如何制备和利用旋转仪自动记录动物的旋转行为,以及用高效液相色谱法测定大脑纹状体内多巴胺的含量。     

Production and elimination of disruptive classroom behavior by systematically varying teacher's behavior

The effects of teacher behaviors on the classroom behaviors of children were investigated by systematically varying approving (praise, smiles, contacts, etc.) and disapproving (verbal reprimands, physical restraint, etc.) classes of teacher behavior. Measures were taken on both teacher and child behaviors. Each day a sample of 10 children was observed. The subject pool was a class of 28 well-behaved children in a middle-primary public school class. The results demonstrated that approving teacher responses served a positive reinforcing function in maintaining appropriate classroom behaviors. Disruptive behaviors increased each time approving teacher behavior was withdrawn. When the teacher's disapproving behaviors were tripled, increases appeared most markedly in the gross motor and noise-making categories of disruptive behavior. The findings emphasize again the important role of the teacher in producing, maintaining, and eliminating disruptive as well as pro-social classroom behavior.     

Die Werturteilsfrage in der Technik

Journal for General Philosophy of Science - Bei den von Ingenieuren verwendeten Dezisionsmechanismen wird aufgrund der Fortentwicklung der Technik die methodologische Sicherung der...     

Hypermnesia for pictures: Incremental memory for pictures but not words in multiple recall trials

Two studies are reported on multiple forced recall following a single visual presentation of a sequence of pictures or words. In both experiments, a hypermnesic memory function (in which performance improved with repeated recall) was obtained for pictures, while a flat, nonincremental function was obtained for words. Interpolation of intervals of thinking between recall trials further enhanced hypermnesia for pictorial items. Retrieval, whether overt (recall trials) or covert (thinking), apparently produces increased net recovery of pictures but not words.     

Are the fruits of research available to all? The effects of sex and academic rank on reprint-sending behavior

There is considerable evidence in the psychological literature that perceived status often has a major effect on behavior. The primary purpose of the present study was to examine the effects of two status variables in an academic setting by monitoring reprint-sending behavior. Reprints were requested from 1,200 authors of psychological articles by men and women of varying academic rank. Neither sex nor academic rank of requester had any significant effect on the total number of responses returned. However, male requesters received responses significantly faster than did female requesters. In addition, subsequent analyses indicated that reprint requests were more likely to be honored by male authors than by female authors.