家兔具有分辨红绿的色觉行为

本文在11只上海家免上进行了色觉行为学的实验研究。通过限制方位、光强等可能成为条件刺激的因素,并排除了声音、气味、背景光刺激等的干扰,确保颜色成为唯一的条件刺激,建立食物性红绿色觉分辨条件反射。经过适应、筛选、驯练和测试,在家兔上建立了对绿光稳固的条件反射。该结果显示兔具有颜色分辨能力。     

Techniques for rotating two or more loading matrices to optimal agreement and simple structure: A comparison and some technical details

Matrices of factor loadings are often rotated to simple structure. When more than one loading matrix is available for the same variables, the loading matrices can be compared after rotating them all (separately) to simple structure. An alternative procedure is to rotate them to optimal agreement, and then compare them. In the present paper techniques are described that combine these two procedures. Specifically, five techniques that combine the ideals of rotation to optimal agreement and rotation to simple structure are compared on the basis of contrived and empirical data. For the contrived data, it is assessed to what extent the rotations recover the underlying common structure. For both the contrived and the empirical data it is studied to what extent the techniques give well matching rotated matrices, to what extent these have a simple structure, and to what extent the most prominent parts of the different loading matrices agree. It was found that the simple procedure of combining a Generalized Procrustes Analysis (GPA) with Varimax on the mean of the matched loading matrices performs very well on all criteria, and, for most purposes, offers an attractive compromise of rotation to agreement and simple structure. In addition to this comparison, some technical improvements are proposed for Bloxom's rotation to simple structure and maximum similarity.This research has been made possible by a fellowship from the Royal Netherlands Academy of Arts and Sciences to the author. The author is obliged to René van der Heijden for assistance in programming the procedures in the simulation study reported in this paper, and to Jos ten Berge, three anonymous reviewers and an associate editor for helpful comments on an earlier version of this paper.     

AN ALTERNATING TREATMENT COMPARISON OF ORAL AND TOTAL COMMUNICATION TRAINING PROGRAMS WITH ECHOLALIC AUTISTIC CHILDREN

An alternating treatment comparison was conducted of the relative effectiveness of oral and total communication training models for teaching expressive labeling skills to three echolalic autistic children. The results of this comparison demonstrated that total communication proved to be the most successful approach with each of the subjects. In addition, the replication of these findings both within and across subjects suggest that total communication may be, in general, the most effective of these two training models for teaching basic vocal language skills to echolalic children. A number of hypotheses are presented that may provide a basis for the demonstrated effect.     

A COMPARISON OF TWO INTERVENTION ROLES: PEER MONITOR AND POINT EARNER

Two fifth-grade students' high levels of off-task and disruptive behavior decreased rapidly during an intervention in which they were appointed peer monitors or point earners. The children worked in dyads in which one child served as a peer monitor and the other child earned points from his or her monitor for good behavior. Points were accumulated as part of a group contingency. We introduced the two appointments in an independent math period and alternated the appointments across days. The peer monitor and point earner roles, when alternated on an every-other-day basis, were equally effective in reducing the students' inappropriate behavior. Furthermore, their behavior during intervention fell well within the range of inappropriate behavior levels exhibited by classmates. The speed with which both students completed their math problems increased during both appointments. The accuracy of their academic work, however, varied; one student improved slightly and the other student decreased slightly in accuracy.     

AN EVALUATION OF GENTLE TEACHING AND VISUAL SCREENING IN THE REDUCTION OF STEREOTYPY

Gentle teaching and visual screening techniques have been used to control severe behavior problems in persons with mental retardation. An alternating treatments design was used to compare gentle teaching, visual screening, and a task-training condition in the reduction of the high-level stereotypy of 3 persons with mental retardation. Following a baseline phase, a task-training condition using standard behavioral techniques was implemented to establish the effects of training the subjects on the tasks. Results showed a modest decrease in stereotypy. This phase was followed by an alternating treatments phase in which visual screening, gentle teaching, and baseline conditions were compared. Both procedures were superior to the control condition in reducing stereotypic behavior, with visual screening being more effective than gentle teaching. When compared with data from the prior phase, gentle teaching was found to be more effective than task training for 2 subjects but less effective for the 3rd, whose stereotypy increased during gentle teaching. Two succeeding phases in which visual screening was implemented across two and then all three daily conditions reduced stereotypy further to near-zero levels. An additional phase with 1 subject demonstrated that the treatment effects of visual screening were easily replicated across therapists. Mixed and idiosyncratic changes in collateral behaviors occurred. For example, “bonding,” the goal of gentle teaching, occurred at the same low levels under both treatments, contrary to the predictions of gentle teaching's proponents. The results indicate that gentle teaching may not be the universal treatment of choice for stereotypy its proponents suggest, and that it requires further empirical evaluation.     

SELF-RECORDING OF ATTENTION VERSUS PRODUCTIVITY

We investigated the relative effects of self-recording of attentive behavior and self-recording of academic productivity with 5 upper elementary-aged special education students in their special education classroom. Following baseline, both self-recording treatments were introduced according to a multielement design. After the multielement phase, we assessed the pupils' performance under a choice condition, faded the overt aspects of the treatment program according to a withdrawal design, and probed maintenance over 5 weeks. Results revealed that both treatments produced clear improvements in arithmetic productivity and attention to task, neither treatment was clearly and consistently superior to the other, pupils preferred the self-recording of attention treatment, the effects were maintained for all pupils, achievement test scores improved, and pupils generally recorded accurately.     

An improved solution for factals: A nonmetric common factor analysis

In FACTALS an alternating least squares algorithm is utilized. Mooijaart (1984) has shown that this algorithm is based upon an erroneous assumption. This paper gives a proper solution for the loss function used in FACTALS.     

MULTIPLE TREATMENT INTERFERENCE IN THE ALTERNATING TREATMENTS DESIGN AS A FUNCTION OF THE INTERCOMPONENT INTERVAL LENGTH

In experimental designs requiring the administration of more than one treatment to the same subject(s), the effect of one treatment may be influenced by the effect of another treatment (Campbell & Stanley, 1963), a phenomenon known as multiple treatment interference. We conducted two studies in which multiple treatment interference in an alternating treatments design was shown to be a function of the length of the intercomponent interval (ICI) separating treatment conditions. In the first study, we evaluated the effects of four different treatments on the mouthing of a severely retarded boy. Under a 1-min ICI no consistent differential responding to treatment was obtained. Differential responding emerged when the ICI was increased from 1 min to 120 min, thus suggesting multiple treatment interference in the lack of differential responding under a 1-min changeover interval. Functional control of the nondifferential and differential responding as a function of the ICI length was replicated in a reversal phase. In the second study, we compared two treatment procedures for the disruptive noncompliant behavior of a moderately retarded boy. Multiple treatment interference (i.e., the lack of differential responding) occurred with the 1-min intercomponent interval. An increase to a 120-min ICI again resulted in differential responding. A replication of multiple treatment interference by a reversal to a short interval phase was not achieved in the second subject. Results of this study support much of the basic literature on discrimination and multiple treatment interference. Major findings of this study are twofold: Multiple treatment interference can depend on the length of the changeover interval between treatments and multiple treatment interference can take the form of a lack of differential responding to various treatments. Implications for future research are discussed.     

Evaluation of two methods of prompting drivers to use specific exits on conflicts between vehicles at the critical exit

The Florida Department of Transportation used a series of changeable-message signs that functioned as freeway guide signs to divert traffic to Universal Theme Park via one of two eastbound exits based on traffic congestion at the first of the two exits. An examination of crashes along the entire route indicated a statistically significant increase in crashes at the first eastbound exit following the actuation of the system. Furthermore, all of the crashes occurred in close proximity to the exit gore (the crosshatched area at exits that drivers are not supposed to enter or traverse) at the first exit. In Experiment 1, behavioral data were collected using an alternating treatments design. These data revealed that reassigning the exit signs was effective in producing a change in the percentage of drivers using each of the two exits. These data also showed that the reassignment of the theme park exit was associated with an increase in the percentage of motor vehicle conflicts that consisted of vehicles cutting across the exit gore. An analysis revealed that the method used for switching the designated or active theme park exit on the series of changeable-message signs led to the presentation of conflicting messages to some motorists, thus resulting in erratic driving behavior (cutting across the exit gore). In Experiment 2, the treatment evaluated the use of a phased method of switching the designated theme park exit to eliminate the delivery of conflicting messages. The new method for switching the designated theme park exit was not associated with an increase in motorists cutting across the exit gore.     

Instructive feedback: A comparison of simultaneous and alternating presentation of non-target stimuli

Instructive feedback involves presenting extra, non-target stimuli in the consequent events for children's responses. Two methods of presenting instructive feedback during direct instruction were compared. These methods involved presenting two extra stimuli on all trials, and presenting the two extra stimuli separately on alternating trials. Preschool students were taught coin combinations using a constant time delay procedure with instructive feedback stimuli added to both praise and correction statements. An adapted alternating treatments design was used to evaluate the two methods of presenting instructive feedback. The students were assessed to determine the extent to which instructive feedback stimuli were learned. The results indicate that students learned some of the instructive feedback stimuli and no consistent differences in the effectiveness of the two presentation methods were noted. Further, relationships between the two instructive feedback stimuli appeared to be established. Implications for instruction and future research are discussed.