Dichotic sequence discrimination: The effect of continued practice

Summary Dichotic sequence discrimination was studied by means of a three-alternative forced-choice method. Two of the alternatives (same) consisted of a single pair of dichotic clicks with the stimulus at one ear preceding the stimulus at the other ear by a given temporal separation (e.g., R-t-L). One of the alternatives consisted of a single pair of clicks with the opposite sequence (e.g., L-t-R). The subjects' task was to discriminate between the different and the same dichotic pairs. The results indicate that discrimination is a nonmonotonic function of t, i.e., V- or U-shaped, with high levels at both short and long temporal separations (t=2 and 4 ms and t=64 and 96 ms) and with lower levels of discrimination for intermediate ts. A second experiment was performed to study the effect of continued practice by subjects trained in dichotic sequence discrimination for ts 4 and 64 ms (high discrimination levels) and for t=16 ms (low discrimination level). There was no systematic trend towards improvement over 8 blocks of 50 trials for each t. Discrimination levels of these ts did not differ between Experiments 1 and 2.Dr. Babkoff is spending the 1979–1981 academic year at the Walter Reed Army Institute of Research, Department of Military Medical Psychophysiology, Forest Glen Annex, Building 189, Washington, D.C. 20012, USAThe experiments were conducted at the Bar-Ilan University, Ramat-Gan, Israel. The authors would like to thank the Bar-Ilan Research Committee for making funds available to conduct the experimentsThis material has been reviewed by the Walter Reed Army Institute of Research, and there is no objection to its presentation and/or publication. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense     

Strategies of rule discovery in an inference task

It has long been known that subjects in certain inference tasks will seek evidence which can confirm their present hypotheses, even in situations where disconfirmatory evidence could be more informative. We sought to alter this tendency in a series of experiments which employed a rule discovery task, the 2-4-6 problem first described by Wason. The first experiment instructionally modified subjects confirmatory tendencies. While a disconfirmatory strategy was easily induced, it did not lead to greater efficiency in discovering the rule. The second experiment introduced subjects to the possibility of disconfirmation only after they had developed a strongly held hypothesis through the use of confirmatory evidence. This manipulation also failed to alter the efficiency of rule discovery. In the third experiment, subjects were taught to use multiple hypotheses at each step, in the manner of Platt's “Strong Inference”. This operation actually worsened performance. Finally, in the fourth experiment, the structure of the problem was altered slightly by asking subjects to seek two interrelated rules. A dramatic increase in performance resulted, perhaps because information which in previous tasks was seen as merely erroneous could now be related to an alternative rule. The four studies have broad implications for the psychological study of inference processes in general, and for the study of scientific inference in particular.     

Perception of spatial and social density

The effects of family size on the perception of three abstract rooms that differed in social and spatial density were studied. The rooms were rated on the dimensions, evaluation, spirituality, activity, and aesthetic appeal. Of the 48 subjects half were from large families with six or more members, and half were from smaller families. Family size had no effect on the perception of the rooms. The room low in spatial density was perceived most favorably, and there was no difference in the perception of a room high in social density and one high in spatial density.     

Vicarious and operant experiences in the etiology of illness behavior: A replication with healthy individuals

The purpose of the present investigation was to replicate a previous study of diabetic patients on the role of parental modeling in the etiology of illness behavior. A random sample of healthy individuals were assigned to an avoidant model (AM) (i.e. parent reported to have avoided work. chores etc. when ill) or non-avoidant model (NAM) group. Subjects subsequently provided retrospective and current information concerning their illness-behavior experiences. The results indicated that individuals with an AM reported more responsibility avoidance when ill currently and as a child compared to the NAM subjects. Additionally. AM subjects reported receiving more positive reinforcement for current illness compared to NAM subjects. It was concluded that the process by which individuals learn to respond to illness may be similar in healthy and chronically-ill individuals but that positive reinforcement for illness may be more likely to be received by healthy individuals during acute illness than by chronically-ill individuals. The present study provides further preliminary support for the learningtheory model of illness behavior.     

Discriminative Versus Reinforcing Properties of Schedules as Determinants of Schedule Insensitivity in Humans

The Psychological Record - Compliance with instructions to respond on response-independent schedules was studied to see if schedule insensitivity is determined by reinforcement of inappropriate...     

The positioning of rhetorical and non-rhetorical questions and the use of self-referencing in print advertising

This research examines the use of questions in advertising through a content analysis of magazine print ads. Three variables are examined: question type (rhetorical vs. non-rhetorical), position (pre-argument vs. post-argument) and self-referencing (present vs. absent). Results reveal that rhetorical (non-rhetorical) questions tend to be used after (before) the arguments to which they refer. Further, self-referencing tends to be used with rhetorical questions in the post-argument position. The findings are discussed illustrating how theoretically-based empirical research can be used to guide decisions in ad practice, and how the practice of advertising can provide support for testable ideas in the conduct of future research.