Coding responses and the generalization of matching to sample in children.

Two experiments studied the conditions of stimulus control necessary for the generalization of relational matching to sample. Matching required the selection of comparison shapes rotated 90 degrees clockwise from the orientation of the corresponding sample. In Experiment 1, five children were taught to: (a) code the orientations of samples, (b) transform sample codings to account for the 90 degree rotation, and (c) repeat the transformed sample coding response to a comparison. High levels of generalization occurred with a set of novel stimuli for which stable sample-coding responses were initially available. In another novel set, where stable sample-coding responses were not initially available, low levels of generalized matching were recorded. Matching performance improved after stable coding responses were trained. In Experiment 2, two children and three adults were trained in a form of the matching task that produced poor generalization despite the presence of stable sample-coding responses. Retraining to modify the stimulus control exerted by these coding responses produced an immediate improvement in generalized matching to sample. Results suggest that the generalization of matching is dependent on structure of stimulus control that the component responses exert on each other.     

Intertrial pellets influence the acquisition and expression of timed appetitive responding in rats

Two experiments examined temporally based changes in the conditioned magazine-entries of rats when a target food pellet arrived at a fixed time before the termination of a conditioned stimulus. Both experiments found that increasing the rate of intertrial pellets systematically interfered with the rate of acquisition. When intertrial pellets were featured in acquisition, their omission on test trials also resulted in a very poorly expressed conditioned response. On test trials preceded by intertrial pellets, however, peak times in groups trained with intertrial pellets were shifted in a rightward direction under a long but not short interstimulus interval. This rightward shift was accompanied by a smaller standard deviation. Our key findings are best accommodated by real-time associative models.     

Secondary generalization and categorization in pigeons

In Experiment 1, one group of pigeons learned to classify a set of stimuli into the human language classes cat, flower, car, and chair (categorization); another group learned to classify the same set into arbitrary classes (pseudocategorization). Then, both groups were trained on a new categorization task and their performance compared to that of a control group that had no initial classification training. Hull's (1943) notion of secondary generalization (generalization that is not based on physical similarity but on mediating associations) predicts that categorization experience will facilitate the learning of a new categorization task, whereas pseudocategorization experience will impair it. However, in Experiment 1, performance on the new categorization task was not differently affected by prior experience. In Experiment 2, pigeons initially trained to classify a set of 48 stimuli (original training) were later trained to classify a subset of four of these stimuli using new responses (reassignment training). Then, they were tested on the 44 remaining stimuli. Performance better accorded with original than with reassignment training, indicating that categorization training did not lead to the formation of equivalence classes of stimuli, in which the equivalence relationship is mediated by secondary generalization. The lack of evidence of secondary generalization implies that our pigeons failed to meet Lea's (1984) criterion for conceptual behavior.     

PARENT EDUCATION PROJECT III: INCREASING AFFECTION AND RESPONSIVITY IN DEVELOPMENTALLY HANDICAPPED MOTHERS: COMPONENT ANALYSIS,GENERALIZATION, AND EFFECTS ON CHILD LANGUAGE

We evaluated the effects of a parent training program consisting of verbal instruction, modeling, and feedback on the affection and responsivity of 3 developmentally handicapped mothers towards their children. The results indicated the following: First, the training package increased maternal physical affection, praise, and imitation of child vocalizations. These parenting skills increased to levels found in comparison groups of nonhandicapped mothers. Second, the training package was more effective than verbal instruction alone, the latter being the predominant method presently used by social service workers. Third, most maternal gains were maintained over a 3- to 18-month follow-up period, although one mother required a reinforced maintenance procedure. Fourth, instructing mothers to generalize served to increase the generalization of newly acquired skills from play times (the training context) to child-care tasks (e.g., diapering, feeding). Fifth, teaching the parents to imitate child vocalizations was related to gains in both the frequency and quality of verbal behavior of the two language delayed children as measured by standardized developmental tests and in vivo comparisons with age-matched children (who had nonhandicapped parents). These results show that behavioral instruction can improve important child-rearing skills of developmentally handicapped mothers, with corresponding benefits to their children.     

Lesions in the anterior thalamic nuclei of rats do not disrupt acquisition of stimulus sequence learning

Four experiments examined the effects of encoding multiple standards in a temporal generalization task in the visual and auditory modalities both singly and cross-modally, using stimulus durations ranging, across different experiments, from 100 to 1,400 ms. Previous work has shown that encoding and storing multiple auditory standards of different durations resulted in systematic interference with the memory of the standard, characterized by a shift in the location of peak responding, and this result, from Ogden, Wearden, and Jones (2008), was replicated in the present Experiment 1. Experiment 2 employed the basic procedure of Ogden et al. using visual stimuli and found that encoding multiple visual standards did not lead to performance deterioration or any evidence of systematic interference between the standards. Experiments 3 and 4 examined potential cross-modal interference. When two standards of different modalities and durations were encoded and stored together there was also no evidence of interference between the two. Taken together, these results, and those of Ogden et al., suggest that, in humans, visual temporal reference memory may be more permanent than auditory reference memory and that auditory temporal information and visual temporal information do not mutually interfere in reference memory.     

EFFECTS OF DIFFERENTIAL REINFORCEMENT ON THE GENERALIZATION OF A REPLACEMENT MAND IN THREE CHILDREN WITH SEVERE LANGUAGE DELAYS

We investigated variables that may influence the generalization of a replacement mand in 3 young children with severe language delays. A multiple baseline design consisting of one stimulus class of manding opportunities that we arbitrarily divided into three categories (i.e., food, toys, and events) was used for each child. During baseline probes, all children manded mainly by reaching, grabbing, or leading. We then taught each child a replacement mand using a single member of the stimulus class. Acquisition of the replacement mand occurred under highly restricted conditions in a setting that was completely isolated from the generalization settings. Postacquisition probes revealed almost exclusive use of old manding forms. Subsequently, extinction of the old forms and reinforcement of the replacement mand were introduced in a sequential fashion. Two children manifested a substantial increase, and 1 child displayed a moderate increase in the occurrence of the replacement mand (i.e., generalization occurred). These results suggest that a differential reinforcement procedure can alter the probability of the occurrence of response class members across a variety of stimulus conditions.     

The logic of generalization: Five principles common to experiments and ethnographies

Both experiments and ethnographies are highly localized, so they are often criticized for lack of generalizability. The present article describes a logic of generalization that may help solve such problems. The logic consists of five principles outlined by Cook (1990): (a) proximal similarity, (b) heterogeneity of irrelevancies, (c) discriminant validity, (d) empirical interpolation and extrapolation, and (e) explanation. Because validity is a property of knowledge claims, not methods, these five principles apply to claims about generalization generated by any method, including both ethnographies and experiments. The principles are illustrated using Rizzo and Corsaro's interesting ethnographies as examples.     

Towards an account of argumentation in science

In this article it is argued that a complex model that includes Toulmin's functional account of argument, the pragma-dialectical stage analysis of argumentation offered by the Amsterdam School, and criteria developed in critical thinking theory, can be used to account for the normativity and field-dependence of argumentation in science. A pragma-dialectical interpretation of the four main elements of Toulmin's model, and a revised account of the double role of warrants, illuminates the domain specificity of scientific argumentation and the restrictions to which the confrontation and opening stages of scientific critical discussions are subjected. In regard to the argumentation stage, examples are given to show that a general account of argumentation, as advocated by informal logicians, is not applicable to arguments in science. Furthermore, although patterns of inference differ in various scientific practices, deductive validity is argued to be a crucial notion in the assessment of scientific arguments. Finally, some remarks are made concerning the burden of proof and the concluding stage of scientific argumentation.     

EVALUATION OF THE GENERALIZED EFFECTS OF A PEER-TRAINING PROCEDURE WITH MODERATELY RETARDED ADOLESCENTS

The use of peer-training procedures by moderately mentally retarded adolescents was evaluated in two experiments. In Experiment 1, 2 students received instruction on peer-training skills to teach a vocational task to 7 classmates. Following instruction, both peer trainers were successful in teaching their classmates to perform the target task and a second untrained (generalization) task. In Experiment 2, 1 peer trainer taught 3 peers to use picture prompts to complete one or two complex vocational tasks. Following instruction by the peer trainer, the trainees independently used novel pictures on novel tasks. The results of both experiments indicate that peer training with moderately handicapped students can be an effective instructional procedure, with generalization occurring for both the trainers (Experiment 1) and the trainees (Experiment 2).     

TEACHING SEVERELY MULTIHANDICAPPED STUDENTS TO PUT ON THEIR OWN HEARING AIDS

Two experiments were conducted with six severely multihandicapped students with hearing impairments to: (a) train the six students to put on their own hearing aids independently, and (b) provide an empirical evaluation of a comprehensive instructional program for putting on a hearing aid by assessing acquisition, maintenance, and generalization of that skill across environments. All six students acquired the skill rapidly, with two students requiring remedial training on one step of the program. Because for two of the original three students the newly learned skill failed initially to generalize to other environments, a second experiment was initiated to assess generalization across environments as well as to replicate the efficiency of the acquisition program. When a variation of the multiple-probe baseline technique was used, the behavior of three additional students generalized to other settings without direct training in those settings.