Estimation of psychometric functions from adaptive tracking procedures

Because adaptive tracking procedures are designed to avoid stimulus levels far from a target threshold value, the psychometric function constructed from the trial-by-trial data in the track may be accurate near the target level but a poor reflection of performance at levels far removed from the target. A series of computer simulations was undertaken to assess the reliability and accuracy of psychometric functions generated from data collected in up-down adaptive tracking procedures. Estimates of psychometric function slopes were obtained from-trial-by-trial data in simulated adaptive tracks and compared with the true characteristics of the functions used to generate the tracks. Simulations were carried out for three psychophysical procedures and two target performance levels, with tracks generated by psychometric functions with three different slopes. The functions reconstructed from the tracking data were, for the most part, accurate reflections of the true generating functions when at least 200 trials were included in the tracks. However, for 50- and 100-trial tracks, slope estimates were biased high for all simulated experimental conditions. Correction factors for slope estimates from these tracks are presented. There was no difference in the accuracy and reliability of slope estimation due to -target-level-for the adaptive track, and only minor differences due to psychophysical procedure. It is recommended that, if both threshold and slope of psychometric functions are to be estimated-from the trial-by-trial tracking data, at least 100 trials should be included in the tracks, and a three- or four-alternative forced-choice procedure should be used. However, good estimates can also be obtained using the two-alternative forced-choice procedure or less than 100 trials if appropriate corrections for bias are applied.     

TOO MUCH REINFORCEMENT,TOO LITTLE BEHAVIOR: ASSESSING TASK INTERSPERSAL PROCEDURES IN CONJUNCTION WITH DIFFERENT REINFORCEMENT SCHEDULES WITH AUTISTIC CHILDREN

Task interspersal procedures have been quite effective in increasing autistic children's motivation to learn. These procedures have typically demonstrated that the inclusion of reinforced maintenance tasks (previously learned tasks) increases responding to new acquisition tasks because more reinforcers, in general, are available. However, studies have not specifically addressed the effects of various schedules of reinforcement, used in conjunction with task interspersal procedures, upon response acquisition. In the present study, a multiple baseline design across subjects was used to assess different reinforcement schedules. Five autistic children participated in learning sessions, during which trials of an acquisition task were interspersed with trials of three maintenance tasks. Correct responses to acquisition tasks were continuously reinforced throughout all conditions, while the reinforcement schedule for competent performance of maintenance tasks differed systematically. Results indicated that all children learned the new tasks when food reinforcers were presented only for acquisition tasks. Results are discussed in terms of behavioral contrast and improving the effectiveness of motivation-enhancing procedures for autistic children.     

THE EFFECTS OF ECHOLALIA ON ACQUISITION AND GENERALIZATION OF RECEPTIVE LABELING IN AUTISTIC CHILDREN

This investigation, consisting of two experiments, was designed to assess the effects of autistic immediate echolalia on acquisition and generalization of receptive labeling tasks. Experiment 1 addressed whether autistic children could use their echolalia to facilitate acquisition. The results indicated that incorporating echolalia (echo of the requested object's label) into the task before manual response (handing the requested object to the experimenter) facilitated receptive labeling. Experiment 2 was designed to determine the effects of incorporating echolalia into task response on acquisition and subsequent generalization. These results indicated that echolalia facilitated generalization for echolalic autistic children but not for functionally mute autistic children. The results of the experiments are discussed in terms of stimulus control. Additionally, it is proposed that perhaps in certain cases, echolalia should not be eliminated, but used to advantage in receptive responding.     

Primary influencers of initial vocational choices for college women

This study of 597 entering college women investigated the characteristics of people they named as the primary influencers for their initial choices of major. College major was considered analogous to vocational field since the sample of students overwhelmingly gave career goals as reasons for choosing a particular major. Characteristics of these primary influencers were compared with those of a sample of individuals influencing male choices. In addition, characteristics of influencers were compared between those influencing females choosing traditional and nontraditional majors. The results indicate that most students, regardless of gender, were influenced by males, particularly fathers. However, a notable percentage of female students, especially those in traditional fields, were influenced by females. Students whose primary influencers were in fields closely related to their own vocational choices reported being more certain of their choices than students citing influencers in unrelated fields. These findings have implications for model-observer similarity, and may necessitate distinguishing between influential people who provide reinforcement for a choice of major and those who provide specific vocational modeling as well as reinforcement for that choice.     

Disability and Family Intervention: A Perspective for Counselors

Thomas H. Hohenshil and Rodney K. Goodyear , Special Assignment Editors Disability and Family Intervention: A Perspective for Counselors Hilda P. Versluys, Physical Rehabilitation and Family Dynamics. Rehabilitation Literature, March-April, 1980, 41 (3–4), 58–65.     

Utilizing ret for effective treatment of adult children of alcoholics

Adult Children of Alcoholics (ACOAs) are a recognized clinical population that includes approximately one of every eight Americans. Although there has been a great deal of interest in this population, studies indicate that only 5% of ACOAs receive effective treatment. The authors assert that Rational-Emotive Therapy can provide ACOAs the education, expression of suppressed feelings, and cognitive restructuring that research indicates is necessary for recovery. This paper discusses issues associated with ACOAs and methods of using RET with this population.Marjorie E. Ferstein, M.S., is an Advisor in the Judicial Program of the University of Georgia.Susan C. Whiston is an Assistant Professor at the University of Nevada, Las Vegas.     

Constancy and illusion of apparent direction of rotary motion in depth: Tests of a theory

An explanation of apparent direction of rotary motion in depth derived from a general theory of perceptual constancy and illusion is proposed with experimental data in its support. Apparent direction of movement is conceived of as exhibiting-perceptual constancy or illusion as a function of apparent direction of orientation m depth for plane objects and apparent relative depth for three-dimensional objects. Apparent reversals of movement direction represent either regular fluctuations between constancy and illusion of direction as a function of valid and invalid stimuli for orientation, or irregular and random fluctuations in their absence. In three preliminary experiments, the apparent movement direction of plane ellipses was investigated as a function of surface pattern information for orientation, and in Experiment I apparent reversals during 20-revolution trials were studied. In Experiment II, apparent movement direction of 3D elliptical V shapes as a function of surface pattern information for relative depth was investigated. In addition to supporting the explanation proposed, the data offer a resolution of a conflict between different theories of apparent reversal of motion in depth.     

Classes and collections: Principles of organization in the learning of hierarchical relations

This study demonstrates that children tend to distort class inclusion relations (e.g., the relation of oaks to trees) into the part-whole structure of collections (e.g., the relations of oaks to a forest). Children aged 6 to 17 were taught novel class inclusion hierarchies, analogous to the relation between oaks, pines, and trees. In one condition, the class inclusion relations were taught by ostensive definition alone, e.g., stating “These are trees” while pointing to trees and, “These are oaks” while pointing to oaks. in the second condition, children were additionally told what would be analogous to “Oaks and pines are two kinds of trees”. With this additional information to constrain their interpretation, even the youngest children correctly interpreted the relation as class inclusion. In contrast, with limited information, children as old as 14 erroneously imposed a collection structure on the inclusion hierarchies. They would deny, for example, that any single tree was a tree (as they should of they thought “tree” meant “forest”), and would pick up several trees despite being asked for a tree. The results indicated that the part-whole structure of collections is simpler to establish and maintain than the structure of inclusion.