不同阅读过程文章信息保持特点的实验研究

本研究主要探讨在自然的阅读与有特定的记忆任务的情况下,学生阅读记忆的特点.从某中学、小学选取高中二年级、初中二年级与小学六年级学生各60人进行实验研究.结果表明,在自然阅读文章的情况下,一般读者所进行的主要是运算性的信息加工活动,是一种筛选保持的过程,服从于中心效应;而在明确的记忆要求下,读者所进行的主要是联结性的信息加工活动,是一种一般的意义记忆过程,服从于首尾效应。     

Temporal control by progressive-interval schedules of reinforcement.

Progressive-interval performances are described using measures that have proven to be successful in the analysis of fixed-interval responding. Five rats were trained with schedules in which the durations of consecutive intervals increased arithmetically as each interval was completed (either 6-s or 12-s steps for different subjects). The response patterns that emerged with extended training (90 sessions) indicated that performances had come under temporal control. Postreinforcement pausing increased as a function of the interval duration, the pauses were proportional to the prevailing duration, and the likelihood of the first response within an interval increased as the interval elapsed. To assess the resistance of these patterns to disruption, subjects were trained with a schedule that generated high response rates and short pauses (variable ratio). When the progressive-interval schedule was reinstated, pausing was attenuated and rates were elevated, but performances reverted to earlier patterns with continued exposure. The results indicated that temporal control by progressive-interval schedules, although slow to develop, is similar in many respects to that for fixed-interval schedules.     

THE EFFECTS OF DIFFERENT REINFORCEMENT CONDITIONS ON THE TEST PERFORMANCE OF MULTIHANDICAPPED DEAF CHILDREN1

The present study explored the effects of different reinforcement conditions on the number of correct responses on the Raven Progressive Matrices. Four groups of 11- to 18-year-old multihandicapped deaf children matched on the basis of mean age and pretest scores were used. The groups were randomly assigned to any of four posttest conditions: end-of-session reinforcement, noncontingent reinforcement, delayed reinforcement, and immediate reinforcement. The mean posttest score of subjects tested under the immediate-reinforcement condition was significantly higher than that of any other group. No significant differences were observed between the mean posttest scores of the three other groups. The practical implications of using reinforcement procedures for testing purposes are discussed.     

Reinforcement magnitude and pausing on progressive-ratio schedules

Rats responded under progressive-ratio schedules for sweetened milk reinforcers; each session ended when responding ceased for 10 min. Experiment 1 varied the concentration of milk and the duration of postreinforcement timeouts. Postreinforcement pausing increased as a positively accelerated function of the size of the ratio, and the rate of increase was reduced as a function of concentration and by timeouts of 10 s or longer. Experiment 2 varied reinforcement magnitude within sessions (number of dipper operations per reinforcer) in conjunction with stimuli correlated with the upcoming magnitude. In the absence of discriminative stimuli, pausing was longer following a large reinforcer than following a small one. Pauses were reduced by a stimulus signaling a large upcoming reinforcer, particularly at the highest ratios, and the animals tended to quit responding when the past reinforcer was large and the stimulus signaled that the next one would be small. Results of both experiments revealed parallels between responding under progressive-ratio schedules and other schedules containing ratio contingencies. Relationships between pausing and magnitude suggest that ratio pausing is under the joint control of inhibitory properties of the past reinforcer and excitatory properties of stimuli correlated with the upcoming reinforcer, rather than under the exclusive control of either factor alone.     

Effects of thematic and lexical priming on readers' eye movements

The study was inspired by Ehrlich & Rayner (1981). In the study semantic context effects were investigated during on-line discourse processing. Readers' eye movements were registered to see whether words that were semantically closely related to the global theme of the text were read faster than words that did not have any apparent semantic link to the discourse theme. In addition, lexical priming was examined by presenting an identity prime earlier in the text. The results showed that non-thematic words were regressed to more often than thematic words. Regressions were typically initiated after reaching a clause or sentence boundary. Regressions were thus assumed to be made in order to integrate non-thematic words into the previous context. Modest negative correlations were found between word's fixation time and its relative predictability. No effects of lexical priming were observed. It was concluded that moderately constraining discourse contexts produce negligible effects on word recognition.     

EVALUATION OF A SOCIAL INTERACTION COACHING PROGRAM IN AN INTEGRATED DAY-CARE SETTING

We used a multiple baseline design across teachers (with a reversal phase for 1 teacher) to evaluate the direct and indirect effects of a structured coaching procedure on the teaching behaviors of 3 day-care teachers. Structured coaching preceding daily caregiver routines resulted in (a) substantial increases in adult delivery of behavioral support of social interaction during group activities with 2- and 4-year-old children and (b) marked collateral increases in positive interactions of socially withdrawn children. Long-term maintenance effects were demonstrated by both the teachers and target children, and social validity measures indicated that the teachers rated coaching very positively on several dimensions. The results are discussed in relation to in-service training of day-care staff, the concept of coaching as a setting event, and the dissemination of teaching technology related to social interaction of young children.     

Two metamodels of causal effects

Two metamodels, termed Model S and Model V, are proposed for definition, measurement, and generalization of quantitative causal effects. The effect is defined as a part change in score in Model S and as a part change in variance in Model V. Two additional changes, total and remainder change, are defined. The latter is due to all other factors or variables than the cause, while total change is the sum of remainder and effect change. Furthermore, it is shown how contrafactual concepts, which imply that some parts of the study situation are supposed to be otherwise, enter into the metamodels. Casual effects are defined and measured in terms of non-contrafactual concepts, except that statistical induction includes contrafactual as well as non-contrafactual inferences. Non-statistical generalization involves both kinds of inferences. Contrafactual definitions are considered inadequate, and a contrafactual interpretation of statistical adjustment is unnecessary and should be replaced by a non-contrafactual one.     

Periodicities within a fixed-interval session

Within-session periodicities in number of responses per interval and postreinforcement pauses were investigated on fixed-interval schedules of 1, 2, and 3 minutes with rats. Postreinforcement pause values and the number of responses in successive intervals were not systematically related. The direction of change of these variables from one pair of intervals to the next revealed periodicities in that the direction of change varied more than would be expected by chance. A response prevention technique used to manipulate the length of time spent responding in an interval had little effect on the postreinforcement pause value of the next interval except when only a single response was permitted in an interval. This procedure tended to reduce the postreinforcement pause value of the next interval to an abnormally low level.     

Issues associated with repeated neuropsychological assessments

Distinguishing practice effects from other factors in repeated neuropsychological assessments are discussed in the context of research studies and clinical/forensic assessments. Potential methodological procedures for reducing the impact of practice effects in research settings are outlined. In contrast, the potential clinical utility and interpretation of practice effects in clinical assessments and forensic evaluations are highlighted.