WHY A BRAIN CAPABLE OF LANGUAGE EVOLVED ONLY ONCE: PREFRONTAL CORTEX AND SYMBOL LEARNING

Abstract. Language and information processes are critical issues in scientific controversies regarding the qualities that epitomize humanness. Whereas some theorists claim human mental uniqueness with regard to language, others point to successes in teaching language skills to other animals. However, although these animals may learn names for things, they show little ability to utilize a complex framework of symbolic reference. In such a framework, words or other symbols refer not only to objects and concepts but also to sequential and hierarchical relationships with other symbols. This process is essential to human mental operations, including language, mathematics, and music. In humans, these operations may have coevolved with the prefrontal area of the cerebral cortex, which is proportionately much larger in humans than in other animals and more intricately linked with other areas of the brain. Analysis of the structure and function of the prefrontal area suggests that it is centrally involved in the operation of higher-order associative relationships involving the subordination of one set of associations to another. This alternate learning strategy apparently appeared at the cost of certain sensory, motor, or limbic abilities. The payoff was symbolic thinking. Humans thus are unique among species, not just for their highly developed language ability but for their odd style of thinking and learning.     

影响学习迁移的几个因素的实验研究

针对前人较多地从学习材料本身的特点或学习者的心理特点出发去孤立地考察对学习迁移的影响这一现象 ,本研究试采用代数运算材料 ,系统地探讨了学习材料的相同要素和学习者概括化认知过程两者之间的内在关系 ,并将相同要素进一步区分为表述形式相似和内在原理相似。旨在对较为复杂的认知学习中迁移的影响因素做更深入的考察。结果表明 :①概括化和相同要素对学习迁移的影响依然存在 ,但需作具体分析。其中 ,前者应成为影响学习迁移的更重要因素。②在学习材料的相同要素中 ,实质上对迁移起作用的是内在原理相似性 ;而表述形式相似性不起主要作用。③概括化因素和内在原理相似性因素之间的交互作用对学习迁移影响极大。     

Improving the spelling performance of students with disabilities

The present study examined the effects of an error correction strategy on the spelling accuracy of students with emotional and/or learning disabilities. The strategy, which asked students to spell a word, view a correct model, and then correct their errors, was compared to a traditional strategy that asked students to write words three times each while viewing a correct model. Results showed that students learned more words in the error correction condition than in the traditional condition. The error correction treatment was shown to be an effective strategy that reduced the number of repetitive spelling practice trials, and was preferred by students.     

母语句法结构对中国学生英语语句理解的影响

中国学生的英语学习受到汉语的影响,尽管这种影响随着学生英语提高而渐趋减小,但当学生的英语达到相当高水平时仍可较明显地观察到。通过实验证明：中国英语专业二年级学生在英语学习中仍受到汉语一定程度的影响,而且在词序方面尤为明显。这种影响的存在表明在中国的英语教学和学习中应给予母语因素以足够的重视。     

Stability criteria

Three approaches to the determination of behavioral stability were examined. In the first, a learning curve was fit to acquisition data (from Cumming and Schoenfeld, 1960), and the “experiment” stopped when the data approached sufficiently close to the theoretical asymptote. In the second, the data were analyzed for variability and linear and quadratic trend. In the third, the experiment was stopped when the magnitude of the daily changes in the data fell below a criterion. Accuracy was measured as deviation between the average value of the dependent variable when the experiment was stopped, and the average value over the last 100 sessions. The first approach was most accurate, but at the cost of requiring the most sessions and being the most difficult to apply. Both the second and third approaches provided acceptable criteria with a reasonable cost-accuracy tradeoff. The second approach permits a continuous adjustment of the criteria to accommodate the variability intrinsic in the experimental paradigm. The third, nomothetic, approach also takes into account the decreasing marginal utility of extended training sessions.     

AN ECOBEHAVIORAL EXAMINATION OF A SIMPLE STRATEGY FOR INCREASING MEALTIME LANGUAGE IN RESIDENTIAL FACILITIES

Typically in large residential facilities for retarded persons, meals are served in an institutional style that does not appear to encourage appropriate peer interactions. An ecological program alternative is serving meals in a family style. The present study was designed to examine both the feasibility of serving family style meals and the effects of family style meal service on mealtime language. Five retarded young adult male residents, who had some conversational skills and appropriate table manners, participated in this study. The experimental design involved a multiple baseline analysis across meals (dinner, lunch, and breakfast). Observers coded the youths' mealtime verbalizations according to the type, content, and direction of the verbalizations and they recorded the length of the meals. The analysis of the verbalization data indicated that during family style meals the participants spoke substantially more often than during institutional style meals. Increases in peer-directed conversation about the meals primarily accounted for the verbalization changes. Family style serving also resulted in the youths spending more time with their meals. In addition, social validation measures suggested that the family style procedures were preferred by the consumers (participants, staff, and concerned community members).     

The development of derived stimulus relations through training in arbitrary-matching sequences

Five-year-old children were taught three-stage sequences of arbitrary matching: A-C, B-C, A-D; A-C, B-D, B-C; or A-C, A-D, B-C. Each stage refers to a sample-comparison relation between stimuli. Unreinforced test probes revealed untrained arbitrary matches (B-D, A-D, and B-D, respectively), derivable by substitution of stimuli with a common sample or comparison function. Additional probes revealed further untrained sample-comparison relations derivable by substitution and identity, including the commuted relations D-B, D-A, and D-B, respectively. These processes may have relevance to conceptual and verbal behavior.     

Hill-climbing by pigeons

Pigeons were exposed to two types of concurrent operant-reinforcement schedules in order to determine what choice rules determine behavior on these schedules. In the first set of experiments, concurrent variable-interval, variable-interval schedules, key-peck responses to either of two alternative schedules produced food reinforcement after a random time interval. The frequency of food-reinforcement availability for the two schedules was varied over different ranges for different birds. In the second series of experiments, concurrent variable-ratio, variable-interval schedules, key-peck responses to one schedule produced food reinforcement after a random time interval, whereas food reinforcement occurred for an alternative schedule only after a random number of responses. Results from both experiments showed that pigeons consistently follow a behavioral strategy in which the alternative schedule chosen at any time is the one which offers the highest momentary reinforcement probability (momentary maximizing). The quality of momentary maximizing was somewhat higher and more consistent when both alternative reinforcement schedules were time-based than when one schedule was time-based and the alternative response-count based. Previous attempts to provide evidence for the existence of momentary maximizing were shown to be based upon faulty assumptions about the behavior implied by momentary maximizing and resultant inappropriate measures of behavior.     

Choice as a function of local versus molar reinforcement contingencies.

Rats were trained on a discrete-trial probability learning task. In Experiment 1, the molar reinforcement probabilities for the two response alternatives were equal, and the local contingencies of reinforcement differentially reinforced a win-stay, lose-shift response pattern. The win-stay portion was learned substantially more easily and appeared from the outset of training, suggesting that its occurrence did not depend upon discrimination of the local contingencies but rather only upon simple strengthening effects of individual reinforcements. Control by both types of local contingencies decreased with increases in the intertrial interval, although some control remained with intertrial intervals as long as 30 s. In Experiment 2, the local contingencies always favored win-shift and lose-shift response patterns but were asymmetrical for the two responses, causing the molar reinforcement rates for the two responses to differ. Some learning of the alternation pattern occurred with short intertrial intervals, although win-stay behavior occurred for some subjects. The local reinforcement contingencies were discriminated poorly with longer intertrial intervals. In the absence of control by the local contingencies, choice proportion was determined by the molar contingencies, as indicated by high exponent values for the generalized matching law with long intertrial intervals, and lower values with short intertrial intervals. The results show that when molar contingencies of reinforcement and local contingencies are in opposition, both may have independent roles. Control by molar contingencies cannot generally be explained by local contingencies.