Rapid acquisition of discrete-trial lever-press avoidance: effects of signal-shock interval

Acquisition of discrete-trial lever-press avoidance learning was studied in three experiments. Experiment I compared a new training procedure, which produces rates of lever-press avoidance learning comparable to those obtained in shuttle boxes, with a “conventional”, less efficient training procedure. A factorial design was used to compare continuous versus intermittent shock and a long-variable versus a short-fixed signal-shock interval. Learning was best in the groups trained with the long and variable interval and poorest in those trained with the short and fixed interval. Type of shock had no effect. Experiment II separated the effects of duration from those of variability of the signal-shock interval. Fixed and variable intervals of 10 and 60 sec were tested and duration was the only significant factor. Experiment III addressed the effect of the differential opportunity to avoid provided by long signal-shock intervals by varying this interval from 10 to 60 sec in 10-sec steps. Only the 10-sec group showed slow acquisition relative to the others. Analysis of avoidance response latencies showed that the distributions for all groups were positively skewed and that skewness increased with increasing duration of the signal-shock interval. At intervals longer than 20 sec, the animals made progressively less use of their increased opportunity to respond. The data do not support the opportunity-to-respond interpretation of the effects of duration of signal-shock interval and suggest that some type of inhibitory process may block lever-press avoidance learning at intervals as short as 10 sec. The significance of these findings for species-specific defense reaction and preparedness theories was emphasized.     

Effects of scopolamine on repeated acquisition of radial-arm maze performance by rats.

Rats repeatedly acquired the performance of selecting only the four baited arms in an automated eight-arm radial maze, with the arms containing food pellets randomly assigned prior to each session. During each 14-trial (trial: obtain all four pellets) daily session, the number of errors (selecting nonbaited arms or repeating arm selections) showed a within-session decline, and choice accuracy for the first four arm selections showed a positive acceleration across trials for all rats. An index-of-curvature statistic, calculated for total errors, was used to quantify both the within- and between-session improvement of performance. Scopolamine (0.03 to 0.3 mg/kg, ip), but not methylscopolamine (0.3 mg/kg), reduced the accuracy of the first four selections of each trial and increased total within-session errors for all rats. Session times also were increased by scopolamine. An examination of within-session accuracy showed only slight signs of improvement at the higher dosages of scopolamine. The results indicate that behavior in transition states maintained by reinforcement contingencies in the radial maze is similar to that maintained by extended chained schedules, despite the fact that some of the stimuli controlling behavior in the maze are absent at the moment behavior is emitted.     

PROGRAMMING “LOOSE TRAINING” AS A STRATEGY TO FACILITATE LANGUAGE GENERALIZATION

This study investigated the generalization of spontaneous complex language behavior across a nontraining setting and the durability of generalization as a result of programming and “loose training” strategy. A within-subject, across-behaviors multiple-baseline design was used to examine the performance of two moderately retarded students in the use of is/are across three syntactic structures (i.e., “wh” questions, “yes/no” reversal questions, and statements). The language training procedure used in this study represented a functional example of programming “loose training.” The procedure involved conducting concurrent language training within the context of an academic training task, and establishing a functional reduction in stimulus control by permitting the student to initiate a language response based on a wide array of naturally occurring stimulus events. Concurrent probes were conducted in the free play setting to assess the immediate generalization and the durability of the language behaviors. The results demonstrated that “loose training” was effective in establishing a specific set of language responses with the participants of this investigation. Further, both students demonstrated spontaneous use of the language behavior in the free play generalization setting and a trend was clearly evident for generalization to continue across time. Thus, the methods used appear to be successful for training the use of is/are in three syntactic structures.     

Effects of d-amphetamine, cocaine, and phencyclidine on the acquisition of response sequences with and without stimulus fading.

In each of three components of a multiple schedule, monkeys were required to emit a different sequence of four responses in a predetermined order on four levers. Sequence completions produced food on a fixed-ratio schedule. Errors produced a brief timeout. One component of the multiple schedule was a repeated-acquisition task where the four-response sequence changed each session (learning). The second component of the multiple schedule was also a repeated-acquisition task, but acquisition was supported through the use of a stimulus-fading procedure (faded learning). In a third component of the multiple schedule, the sequence of responses remained the same from session to session (performance). At higher doses, d-amphetamine, cocaine, and phencyclidine decreased the overall rate of responding and increased the percent errors in all three components. At lower doses, however, the three drugs produced selective effects on errors. Errors were increased in the learning component at lower doses than those required to disrupt the behavior in the faded-learning component. The performance component tended to be the least sensitive to disruptive drug effects. The data are consistent with the view that stimulus fading can modulate the effects of drugs on acquisition.     

Psychometric evaluation of the situation test of heterosocial skill

This study examined various psychometric properties of Forms A and B of the Situation Test, developed by Rehm and Marston (Journal of Consulting and Clinical Psychology, 1968, 37, 565–574) for the assessment of heterosocial skill and anxiety. A third test form composed of heterosocially irrelevant items was also examined for comparison purposes. Split-half, alternate-form, and interresponse consistency was determined for measures of skill, anxiety, response latency, and response duration. Differences across test forms on these measures were also investigated. Subsequently, criterion-related validity was examined relative to three criteria of heterosocial skill. Results indicated that two measures, anxiety and response duration, displayed adequate internal consistency, while that of skill and response latency was marginal. Interresponse consistency was moderately low for all three test forms. Comparisons of mean performances across forms revealed significant differences, with heterosocially irrelevant items appearing easier, in general, than the heterosocial items of Forms A and B. Lastly, significant predictions of peer-reported heterosocial behavior were obtained for all three test forms, but two self-report criteria were not found to be related to test behavior. Various implications of these findings are discussed.Portions of this research were completed while the authors were affiliated with the University of Georgia, Athens, Georgia. The advice and consultation provided by the late William K. Boardman is gratefully acknowledged. Appreciation is also extended to Michael Breakwell, Linda Maertzweller, Steven Ray, and Jan Rockley for their assistance with data collection.Copies of assessment material and specific instructions to subjects are available upon request.     

Do early lexical skills predict language outcome at 3 years? A longitudinal study of French-speaking children

Early language development is considered critical for children’s adjustment in school, for social adaptation and for later educational achievement. Despite the role of children’s receptive skills as a foundation for later productive word use, receptive language skills have received surprisingly little attention. The present research extends recent work on the prediction of preschool language skills by exploring whether a decontextualized measure of lexical comprehension can account for unique variance in preschool language skills above and beyond parent report and how early such a prediction can be made. For this purpose, 65 French-speaking children have been tested at 16, 22, 29 and 36 months.The results of the current study suggest that up to the age of two, although parent reports of lexical comprehension and/or production account for a portion of variance in later receptive, productive or general language outcome, they have less predictive validity than a direct measure of early lexical comprehension. By contrast, after age two, parent reported vocabulary production is the strongest predictor of later language production skills.     

Acquiring variation in an artificial language: Children and adults are sensitive to socially conditioned linguistic variation

Languages exhibit sociolinguistic variation, such that adult native speakers condition the usage of linguistic variants on social context, gender, and ethnicity, among other cues. While the existence of this kind of socially conditioned variation is well-established, less is known about how it is acquired. Studies of naturalistic language use by children provide various examples where children’s production of sociolinguistic variants appears to be conditioned on similar factors to adults’ production, but it is difficult to determine whether this reflects knowledge of sociolinguistic conditioning or systematic differences in the input to children from different social groups. Furthermore, artificial language learning experiments have shown that children have a tendency to eliminate variation, a process which could potentially work against their acquisition of sociolinguistic variation. The current study used a semi-artificial language learning paradigm to investigate learning of the sociolinguistic cue of speaker identity in 6-year-olds and adults. Participants were trained and tested on an artificial language where nouns were obligatorily followed by one of two meaningless particles and were produced by one of two speakers (one male, one female). Particle usage was conditioned deterministically on speaker identity (Experiment 1), probabilistically (Experiment 2), or not at all (Experiment 3). Participants were given tests of production and comprehension. In Experiments 1 and 2, both children and adults successfully acquired the speaker identity cue, although the effect was stronger for adults and in Experiment 1. In addition, in all three experiments, there was evidence of regularization in participants’ productions, although the type of regularization differed with age: children showed regularization by boosting the frequency of one particle at the expense of the other, while adults regularized by conditioning particle usage on lexical items. Overall, results demonstrate that children and adults are sensitive to speaker identity cues, an ability which is fundamental to tracking sociolinguistic variation, and that children’s well-established tendency to regularize does not prevent them from learning sociolinguistically conditioned variation.     

幼儿的游戏行为及其与社会技能、学习行为的典型相关分析

对4～6岁儿童的游戏行为、社会技能和学习行为进行问卷调查.结果发现,幼儿的游戏行为发展存在显著的年龄和性别差异.典型相关分析结果表明,游戏行为对幼儿社会技能的影响作用大于社会技能对游戏行为的影响作用,同时,游戏中的亲社会行为对幼儿的学习能力、学习动机有显著的促进作用,而破坏、退缩行为对学习能力和学习动机的形成有阻碍作用.     

新手-熟手-专家型教师成就目标定向与人格特征的研究

本研究采用量表法考察三种类型教师成就目标定向与人格特征的特点。结果表明 ,与普通成人相比 ,我国中学教师比较外倾 ,精神质水平更高。三种类型教师在任务目标上存在显著性差异 ,新手型教师的任务目标水平显著低于熟手型教师 ;而在成绩目标上 ,不存在显著性差异。新手型教师在精神质维度上与熟手型教师存在显著性差异 ,其精神质水平显著低于熟手型教师 ,熟手型教师在神经质维度上与专家型教师存在显著性差异 ,其神经质水平显著低于专家型教师 ,神经质水平高是专家型教师典型的人格特征。