An optimum value for detection probability

In many psychoacoustic experiments, an experimenter wishes to determine the effects of one or more treatments Ito the subjects, or to the stimuli, or to both) with as little experimental labor as possible. The experimenter is often able to control the similarity of the stimuli and is thus free to choose a base level of performance before the treatment is applied. On the basis of the model presented in this paper, the base level of performance that best enables any change in performance due to the treatment to be detected is predicted. A relatively high base-level performance of 95% correct discrimination results from the model, although practical constraints may dictate a somewhat lower value. An experiment (involving pitch discrimination) that provides data supporting the model is also reported. The model is applicable only to the two-alternative/forced-choice experimental paradigm.     

Basic statistics and the inconsistency of multiple comparison procedures.

This paper has two main themes. First, the various statistical measures used in this journal are summarized and their interrelationships described by way of a flow chart. These are the pooled standard deviation, the pooled variance or mean square error (MSE), the standard error of each treatment mean (SEM) and of the difference between two treatment means (SED), and the least difference between two means which is significant at (e.g.) the 5% level of significance (LSD(5%)). The last three measures can be displayed as vertical bars in graphs, and the relationship between the lengths of these bars is graphically illustrated. It is suggested that the LSD is the most useful of these three measures. Second, when the experimenter has no prior hypotheses to be tested using analysis of variance "contrasts," a multiple comparison procedure (MCP) that examines all pair-wise differences between treatment means, may be appropriate. In this paper a fictitious experimental data set is used to compare several well-known McPs by focussing on a particular operating characteristic, the consistency of the results between an overall analysis of all treatments and an analysis of a subset of the experimental treatments. The procedure that behaves best according to this criterion is the unrestricted least significant difference (LSD) procedure. The unrestricted LSD is therefore recommended with the proviso that it be used as a method of generating hypotheses to be tested in subsequent experimentation, not as a method that attempts to simultaneously formulate and test hypotheses.     

Comparative effectiveness of patterned biofeedback vs meditation training on EMG and skin temperature changes

This study examined whether a low arousal, relaxation pattern of frontalis EMG decreases and peripheral skin temperature increases could be attained more effectively through biofeedback or meditation training. Thirty female subjects, ranging in age from 21 to 59, were randomly assigned to one of three groups: patterned biofeedback, clinically standardized meditation or control. Prior to training, subjects were administered the EPI. Each subject was seen weekly for seven sessions. Subjective experiences and time spent practising at home were also recorded. Repeated measures ANCOVA's performed on the EMG and skin temperature means indicated that the meditation group showed significantly lower EMG levels at the end of treatment than the control group. No group had significant temperature increases nor were there any significant differences in practice time. The biofeedback group had difficulty in patterning the two feedback signals simultaneously. Extraverts in the control group had the highest EMG levels. The most positive subjective reports came from subjects in the meditation group. Meditation offers a viable alternative as a relaxation procedure, requiring little time to learn and devoid of any performance criteria levels.     

A fast procedure for studying conditional accuracy functions

This paper describes a procedure for obtaining conditional accuracy functions(CAFs) from naive observers and a restricted number of trials. The method permits the experimenter to counter the subjects’ tendency to favor accuracy in tasks in which stimulus discrimination is easy. Each time a block of 12 trials contains less than three errors, observers are instructed, by means of a speed-up signal, to respond faster. The subject is continuously informed about her/his effective reaction time. The data show that the desired speed-accuracy tradeoff was obtained within each of the 7 observers. The mean percent error was around 25%.     

Feedback of Information About the Values and Attitudes of Self and Others as Determinants of Long-Term Cognitive and Behavioral Change1

Previous experiments designed to modify persons' values and subsequent attitudes and behavior have used direct self-confrontation procedures to arouse self-dissatisfaction in subjects. The present study compared the effects on values and behavior of the previously used self-confrontation procedure with a modified value-change procedure which did not confront subjects with information about their own values. Both procedures resulted in college students significantly increasing their ranking of the values equality and freedom. These changes were evident 4 weeks after the experimental procedures. Four months after the experimental treatments subjects were solicited to behaviorally support various activities of the Committee to End Racism, and subjects in both experimental groups showed a significantly greater behavioral effect than did control subjects. Thus, significant long-term value and behavioral change may be experimentally induced even when subjects are not provided objective information about their own value-attitude system.     

Effects of a verbal warning and overcorrection on stereotyped and appropriate behaviors

In Experiment I, the effects of a verbal warning, such as is used in Overcorrection, delivered contingently on the stereotyped mouthing behavior of two autistic/retarded children were examined. A multiple baseline design across subjects was used. The results indicated that the mouthing of one child was reduced to a nearzero level and mouthing of the second child was moderately reduced. Appropriate toy play and inappropriate object manipulation failed to show systematic changes in occurrence when mouthing was decelerated. In Experiment II, the same subjects and experimental design were used to assess the effects of a positive practice Overcorrection procedure delivered contingent on mouthing behavior. Overcorrection reduced the mouthing of both subjects. There were no systematic changes in inappropriate object manipulation but one subject did demonstrate an increased occurrence of appropriate toy play. In addition, this subject often engaged in aggressive/escape behaviors during Overcorrection, suggesting that the procedure was aversive to him.     

The effects of value confrontation and reinforcement counseling on the career planning attitudes and behavior of adolescent males

An experiment was conducted to compare the relative effectiveness of a value confrontation procedure and a procedure based on verbal operant conditioning in enhancing career development attitudes and increasing the frequency of information-seeking behavior in rural adolescent males. Ninety subjects were identified as internally controlled or externally controlled based on their locus of control scores and then randomly assigned to one of the two experimental treatment groups or a control group. The value confrontation procedure involved developing an awareness of self-dissatisfaction about one's career planning and relating this self-dissatisfaction to the importance one gave to the values logical and responsible. These values had been identified empirically in this study as having a relationship to career planning. The reinforcement counseling treatment involved the interpretation of individual career maturity data followed by the verbal operant conditioning of responses indicative of career maturity. Post tests administered 7 weeks after the treatments showed that the value confrontation procedure resulted in significantly greater frequency of information seeking for internally controlled subjects when compared to the reinforcement counseling and control procedures. No treatment was significant in increasing the maturity level of career development attitudes.     

A sensitive rank test for comparing the effects of two treatments on a single group

By taking advantage of an experimental design which increases the number of observations per subject, the sensitivity of the proposed test is increased. In the first of a series of subexperiments, the score of a randomly selected experimentalS is ranked with the scores of the remaining (control)Ss, and the experimentalS is discarded. This procedure is repeated until oneS remains. The test criterion,R _n , is the sum of ranks of the experimentalSs; its exact sampling distribution, a normal approximation, and the sensitivity of the test relative to the WilcoxonT, are described. Because of the large number of scores obtained, the test is particularly useful when preparingSs is more costly than testing them, e.g., in tests following involved conditioning procedures. Since eachS is discarded after experimental treatment, the test fills a real need in studies involving radiation, ablation, or other irreversible treatments.The test criterion, the associated experimental procedure, and the measure of sensitivity are due to SHR; the generating function, tables, and large sample approximation are due to JNC.     

PATTERNS OF EXPERIENCE AND THE ACQUISITION OF CONCRETE TRANSITIVITY OF WEIGHT IN EIGHT-YEAR-OLD CHILDREN

The effects of empirical control vs. no empirical control, and of fixed vs. free procedure on the acquisition of transitivity of weight was studied. The fixed procedure involved practice on the sequence A > B, B > C, A > C, whereas the free procedure merely required the children to order triads of objects according to weight. Around thirty per cent of the subjects acquired transitivity, but none of the experimental variables had any effect. It is concluded that empirical control is unimportant. The lack of effect of free vs. fixed procedure is contrary to some earlier findings with younger children, who profited only from a free procedure.     

Click monitoring revisited: An on-line study of sentence comprehension

Spoken sentence comprehension is based upon rapid and complex psychological processes, yielding a constantly fluctuating cognitive load. The aim of this study was to evaluate on-line click monitoring, a classical but poorly exploited experimental method, which should allow for an easy measurement of processing load at any chosen point of experimental sentences. In Experiments 1 and 2, we obtained longer latencies to clicks located at the boundary of reversible object relative clauses than to clicks identically located in subject relatives and to clicks located earlier within object relatives. Experiment 3 further revealed that this effect of syntactic type was specific to transposed object relatives and did not occur with normal object relatives. In Experiment 4, we observed longer latencies with semantically reversible than with irreversible sentences, but no difference between actives and passives. These results were obtained under strict control of potential lexical and phonological biases, and suggest that on-line click monitoring may be one useful tool in the study of sentence comprehension.     

Human concurrent performances: The effects of experience, instructions, and schedule-correlated stimuli

In order to investigate the effects of separate exposures to single schedules, of unique schedule-correlated stimuli, and of independency-informing instructions upon choice under concurrent variable-interval schedules, 28 human subjects were divided into eight groups. Each subject was exposed to a baseline procedure, an experimental procedure, and a return to the baseline procedure. Different combinations of these three manipulations were applied to the different groups only during the experimental phase (except for the independency-informing instructions, which were given to half of the groups at the start of training). For the group of subjects exposed to the combination of all three manipulations, the logarithms of the ratios of response frequencies tended to be linearly related to the logarithms of the ratios of reinforcement frequencies during the experimental phase. These orderly effects were not obtained with subjects in the other groups. The results suggest that human choice was well described by the generalized matching law when the three manipulations were simultaneously in effect, and that unreported differences in the use of these three procedural variables might partly account for contradictions between results in previous studies of human concurrent performance.     

The separate and combined effects of covert and overt rehearsal in developing assertive behavior

The present investigation evaluated the separate and combined effects of covert modeling and overt rehearsal as a means of developing assertive behavior. Nonassertive clients (n = 66) received one of three treatments: covert modeling, overt rehearsal and covert modeling-overt rehearsal combined. A delayed-treatment group was included in the design to serve as a no-treatment control condition before clients were reassigned randomly to one of the three treatments. Treatments led to significant improvements on self-report and behavioral measures of assertiveness and self-efficacy. Although covert and overt rehearsal treatments were equally effective, the combined procedure led to significantly greater improvements which were evident at posttreatment and at an 8-month follow-up assessment. Treatment effects generalized to novel role-play situations and brought clients to the level of other persons who regarded themselves as adept in social situations requiring assertive behavior.     

Effects of hypnosis and imagery training on naming behavior in aphasia

The effects of hypnosis and imagery training on the naming behavior of three subjects with Broca's aphasia were investigated using a multiple baseline design across subjects. Treatment consisted of the induction of hypnosis, followed by guided imagery focused on the physical and functional attributes of stimulus objects. Measures of naming ability on both trained and untrained items were taken at baseline, after every training session, and a few hours after training each day. Measures were also taken of imagery ability, hypnotic susceptibility, and psychological state. Results indicated that treatment facilitated improvement in naming ability, over baseline level, for two subjects. In the case of the third subject, the verbal label was incorporated into the imagery procedure following 10 training sessions. Subsequently, this subject's naming behavior improved over baseline level. The results are discussed in terms of current theory and research in neuropsychology and cognitive psychology.     

Response-contingent positive stimulation of the part-word repetitions displayed by four stutterers

To assess the effect of response-contingent positive stimulation on the frequency of part-word repetitions displayed by stutterers, a single subject design was used. Four subjects were seen separately in an experimental session comprised of initial, experimental and final segments. During the experimental segment, money, the positive stimulus, was delivered contingent upon the occurrence of a part-word repetition.The data were analyzed statistically to determine the significance of differences in the frequency of part-word repetitions. This analysis did not demonstrate an effect of response-contingent positive stimulation on the part-word repetitions of any of the four subjects.The evidence obtained in this study supports the findings of previous research; some verbal behaviors of stutterers are unaffected by response-contingent stimulation. It appears necessary to investigate the effect of response-contingent stimulation on other separate behaviors as whole word repetition, phrase repetition, and hesitation for determination of their manipulability. The successful use of this procedure as a therapeutic treatment is dependent upon such a differential behavioral analysis.     

The effects of instructional set on physiological response to stressful imagery

Centrally mediated or cognitive variables have received considerable attention in clinical research. With the establishment of the effectiveness of such specific treatment techniques as systematic desensitization (Paul. 1969a. 1969b). a question arises as to the influence of cognitions on process and outcome variables in such learning based treatments (Lang. 1971). Research investigating the influence of demand characteristics and subject expectancies has demonstrated such centrally mediated variables can significantly influence overt, behavioral and self-report measures of fear, stress, or anxiety (cf. Borkovec. 1972: Marcia. Rubin and Efran. 1969; McGlynn. Maelia and Nawas. 1969: McGlynn. Reynolds and Linder. 1971: Oliveau. Agras. Leitenberg and Wright. 1969; Rappaport. 1972: Rosen. 1974).However. Borkovec (1972) and Rappaport (1972) failed to obtain expectancy effects on physiological measures of anxiety. Neither investigation provided for an independent assessment of subjects' actual expectancies, or belief in the instructions, as recommended by Davison and Wilson (1973). Borkovec administered clinical procedures over four sessions and varied the information communicated about the ‘purpose’ of the treatments (physiological versus therapeutic instructions). Differential rationales for differential expectancies of physiological reactivity were not provided. After each session, subjects reviewed the same false physiological records depicting reductions in fear responses. Although these changes were explained either physiologically or therapeutically. the fact that such reductions were emphasized should have attenuated differences between groups. Rappaport (1972) exposed subjects to a fearful stimulus and varied the suggestion and rationale for the pseudotreatment: no expectancy (stress research): therapeutic expectancy (fear reduction); and negative expectancy (fear increase). The lack of an independent assessment of the expectancy manipulation, as well as the exclusion of a specific therapeutic procedure, make it impossible to interpret the results in relation to expectancy effects on physiological fear responses during the administration of therapeutic procedures. There is other evidence, however, that suggestion and instructional set can significantly influence somatic and autonomic response systems (Barber. 1961. 1965; Sternbach. 1964. 1965).The primary purpose of this study was to evaluate the effects of instructional set on physiological responses to stressful imagery. This was an early step in a research program investigating the effects of instructional and informational variables on physiological responses of clinical interest. One half of the subjects received abbreviated live relaxation training (R) as described m a manual by Bernstein and Borkovec (1972) and based upon the original work of Jacobson (1938). The other half received an inert placebo pill and undertook a target detection task (P). The latter procedure was similar to that used by Paul (1966). Although both procedures had previously been shown to have relaxing effects, the P task was included as an additional control for any potential effects specific to the tension-release procedure of R. In order to evaluate the effects of instructional set, one half of each of the above two groups received instructions designed to lead to an expectancy of response inhibition to stressful imagery by the respective procedure (Decrease Stress Response. DSR). while the other half received instructions designed to lead to an expectancy of an increased response to stressful imagery by the respective procedure (Increase Stress Response. ISR). Each subject visualized three individually specified items that were the most frightening scenes imaginable prior to training and four times after training visualized the scene producing the largest response. Considerable effort was devoted to eliciting from each subject the most frightening items possible for her. and it was clear from subject comments that the items did elicit negative emotional responses.Since previous research (Barber. 1961. 1965; Sternbach. 1964. 1965) indicated that instructional set can influence physiological reactivity, it was hypothesized the DSR) subjects should exhibit a greater reduction in emotional response from pre- to posttraining than ISR subjects.     

Reducing stereotyped behavior using momentary dro: An experimental analysis

Momentary DRO, a little-used variant of DRO, was compared with a more traditional DRO procedure in the reduction of stereotyped behavior displayed by five subjects with severe mental retardation. Momentary DRO appeared to be more effective than the traditional procedure for three subjects, less effective for one subjects and to increase the stereotyped behavior of the final subject above baseline levels, These findings are discussed in relation to response covariation effects, treatment maintenance and case of implementation.     

Self-regulation in the modification of disruptive classroom behavior

This study compared self-regulation and external regulation procedures in the treatment of children's disruptive classroom behavior. After baseline data were collected, three of the four most disruptive children in each of 10 first- and second-grade classrooms received reinforcement for achieving low rates of disruptive behavior. The fourth child served as a control subject throughout the experiment. Two of the three experimental subjects were then taught to self-observe their own disruptive behavior. In the final reinforcement period, these subjects were given control over dispensing reinforcers to themselves, based on their self-collected behavioral data while subjects in the other experimental group continued with the externally managed reinforcement. In extinction, reinforcement was discontinued for all subjects, but one of the self-regulation subjects in each classroom continued overtly to self-observe. Results indicated that both reinforcement programs reduced disruptive behavior. The self-regulation procedures were slightly more effective in reducing disruptiveness than was the external regulation procedure, and this advantage persisted into extinction. These results suggest that self-regulation procedures provide a practical, inexpensive, and powerful alternative in dealing with disruptive behavior in children.     

ESTABLISHMENT OF NONDELUSIONAL RESPONSES IN A SOCIALLY WITHDRAWN CHRONIC SCHIZOPHRENIC1

Multiple treatment interventions including instructions, modelling, timeout, avoidance of repetition, and reinforcement were successful in establishing factual answers to personal background questions in a withdrawn and socially unresponsive chronic schizophrenic. The subject had previously persisted in giving only delusional responses to these questions. A multiple-baseline design across verbal replies to personal background questions demonstrated that the changes in behavior were brought about by the treatment interventions. During baseline, the subject was reinforced for any response to four questions. The experimental interventions were then introduced for the first question and moved sequentially to an additional question when the subject's responses reached the criterion of at least 80% correct for two consecutive sessions. Introduction of the experimental interventions produced an increase from a baseline level of zero to at least 80% correct for each question. The use of the token reinforcement procedure was faded out after the subject was able to answer all four questions correctly at least 80% of the time for two consecutive sessions. Fading of the token reinforcement procedure was accomplished by using increasingly intermittent schedules of token reinforcement during the last seven sessions. In the final session, no tokens were used to reinforce the subject's responding. Nine-, ten-, and 12-month followup interviews were conducted to evaluate the maintenance of treatment gains. Maintenance was found to be complete at the nine- and 10-month followups, but at the 12-month followup interview, the subject answered one question incorrectly. This study replicates an investigation previously reported in this journal.     

ANALYZING UTTERANCES AS THE OBSERVATIONAL UNIT

If utterances are the observational unit of analysis and there are no sequential patterns to the interaction, two alternative statistical models may be applied. A hierarchical design in which utterances are nested within subjects and subjects are nested within treatment condition is considered. One method of analysis pools utterances within treatment condition; the other method collapses across utterances to obtain subject means. Inappropriate application of the pooling model instead of the subject means model can lead to Type I errors, decreased generalizability, and inflated variance estimates that attenuate univariate and multivariate correlations. The effect of utterance reliability on the apparent unidimensionality and parallelism of multiple indicators is also discussed.