Univariate repeated measures techniques applied to multivariate data

Repeated measures designs in psychology have traditionally been analyzed by the univariate mixed model approach, in which the repeated measures effect is tested against an error term based on the subject by treatment interaction. This paper considers the extension of this analysis to designs in which the individual repeated measures are multivariate. Sufficient conditions for a valid multivariate mixed model analysis are given, and a test is described to determine whether or not given data satisfy these conditions.     

A significance test for multisample sphericity

The paper obtains a maximum likelihood criterion test for multisample sphericity. The test contains Mauchly's sphericity test as a special case.I would like to thank Professor R. E. Bargmann for his most valuable help.     

THE USE OF PHYSICAL RESTRAINT IN THE TREATMENT OF SELF-INJURY AND AS POSITIVE REINFORCEMENT

Two experiments investigated the effects of a treatment package on the self-injurious behavior of three profoundly retarded persons who appeared to enjoy the physical restraints used to prevent their self-injury. The treatment package included physically restraining subjects contingent on increasing periods of time during which no self-injury occurred, and providing them with toys and attention during intervals between restraints. A reversal and multiple-baseline analysis documented that the rapid and complete reduction in self-injury by all subjects was due to this treatment package. Because these results suggested that physical restraint might function as a positive reinforcer, in a third experiment physical restraint was applied contingent on a marble placement response with one subject. A reversal design demonstrated that toy play systematically increased when each response resulted in restraint. The experiments have implications for the nonaversive remediation of self-injury in individuals who are restrained, as well as for the development and maintenance of self-injury in natural settings.     

Repeated acquisition of conditional discriminations

A new technique was developed to study the repeated acquisition of conditional discriminations. Using a discrete trial procedure, pigeons were required to learn during each session a different two-member chain of conditional discriminations. Key color and geometric forms were used as stimuli. After the pigeons had reached a steady state of relearning (40 to 60 sessions), the technique was used to investigate variables that have previously been shown to affect the repeated acquisition of response sequences. Various (0 to 90 seconds) durations of timeout for errors were investigated in Experiment I. The stimulus change associated with a timeout, rather than its duration, was found to be the critical variable in acquisition of the discrimination. Extended training on a single chain was found to reduce total errors across sessions in Experiment II. Extended training (three sessions) did not, however, change the pattern of within-session error reduction. In some cases, extended training facilitated acquisition of a partially reversed discrimination. In Experiment III, color rather than chain position was found to control behavior, for three of the four birds, as the second stimulus dimension in the conditional situation. The results of these experiments replicate and extend previous findings concerning some of the variables that affect the repeated acquisition of response sequences.     

Constructing measures with maximum reliability

The scoring of response vectors to give maximum test-retest correlation is investigated. Simple sufficiency arguments show that the form of the best scores is very restricted. A general method is given for finding the best scores, deriving the best scores for the normal factor model, and showing by calculation of several particular cases that for a standard model for binary response it is easy to approximate the best scores.     

Response patterns and cardiovascular effects during response sequence acquisition by humans.

The effects of temporal delays imposed between successive responses and of vitamin C administration were examined on the acquisition of response sequences and on cardiovascular reactivity during sequence acquisition. Thirteen adult subjects (6 female, 7 male), in good health, gave written consent prior to participating in 12 weekly 45-min sessions. Points, exchanged for money after each session, were presented when subjects completed 15-response sequences on a touch-sensitive three-response keypad. A position counter increased from 0 to 14 as subjects emitted correct responses in the sequence. Four novel 15-response sequences were presented each session. No delays were imposed between successive responses during the acquisition of one sequence; delays were imposed immediately following each response during the acquisition of a second sequence, thereby delaying response feedback; delays were imposed following feedback during acquisition of a third sequence, resulting in the removal of the stimulus correlated with sequence position; and, as a control condition, delays were imposed following feedback, but stimuli correlated with sequence position were reinstated prior to the next response during acquisition of a fourth sequence. Subjects were exposed to one of two delay durations (0.2 and 0.5 or 0.5 and 1.0 s) each session, and delay durations alternated every session. During Weeks 5 to 8, subjects received 3 grams of vitamin C per day, whereas during Weeks 1 to 4 and 9 to 12, subjects received placebo under single-blind conditions. All subjects acquired the sequences, as evidenced by decreasing percentages of incorrect responses across trials. When temporal delays were imposed between successive responses during sequence acquisition, acquisition efficiency was enhanced. Examination of response latencies suggested that the status of preceding responses (i.e., correct or incorrect) rather than the status of the position counter influenced subsequent responding. Cardiovascular effects were inversely related to the length of the temporal delay. Neither cardiovascular reactivity or sequence acquisition were related to vitamin C administration.     

On the generalization of attitude accessibility after repeated attitude expression

The more accessible an attitude is, the stronger is its influence on information processing and behavior. Accessibility can be increased through attitude rehearsal, but it remains unknown whether attitude rehearsal also affects the accessibility of related attitudes. To investigate this hypothesis, participants in an experimental condition repeatedly expressed their attitudes towards exemplars of several semantic categories during an evaluative categorization task. Participants in a control condition performed a non‐evaluative task with the same exemplars and evaluated unrelated attitude objects. After a 30‐minute interval, participants in the experimental condition were faster than controls to evaluate not only the original exemplars but also novel exemplars of the same categories. This finding suggests that the effect of attitude rehearsal on accessibility generalizes to attitudes towards untrained but semantically related attitude objects. © 2016 The Authors. European Journal of Social Psychology published by John Wiley & Sons, Ltd.     

Children's recall and source monitoring of a repeated event using a timeline as an interview aid

Investigators sometimes use timelines (visual depictions of time) to help children identify temporal information from experienced events or details from a particular instance of a repeated event. However, little is actually known about the efficacy of this visual aid on children's memories. Six‐ to 9‐year‐olds participated in four occurrences of a repeated event and were later interviewed with or without the use of a timeline. Children in the timeline condition were less accurate and made more source‐monitoring errors than those in the control condition. For items that appeared consistently throughout the events, a suggestibility effect was more evident for older children who used the timeline than those who did not. Overall, there was no clear evidence in support of the visual aid. Despite its popularity, our findings suggest that timelines should be further examined to establish whether, and under what circumstances, they might be used in investigative contexts.     

Assessment of deviant arousal in adult male sex offenders with developmental disabilities

Ten individuals, residing in a treatment facility specializing in the rehabilitation of sex offenders with developmental disabilities, participated in an arousal assessment involving the use of the penile plethysmograph. The arousal assessments involved measuring change in penile circumference to various categories of stimuli both appropriate (adult men and women) and inappropriate (e.g., 8- to 9-year-old boys and girls). This approach extends the existing assessment literature by the use of repeated measurement and single-subject experimental design. Data from these assessments were analyzed to determine if clear and informative outcomes were obtained. Overall, three general patterns of results emerged. Some participants showed differentiated deviant arousal or higher levels of arousal to specific inappropriate stimuli (deviant is a term used in the existing sex-offender literature to describe this type of arousal). Other participants showed undifferentiated deviant arousal, in which case they showed nonspecific arousal to inappropriate stimuli. The remaining participants showed no arousal to inappropriate stimuli but did show arousal to appropriate stimuli. Implications for assessment, treatment, and future directions are discussed.     

Functional analysis of self-injurious behavior and its relation to self-restraint

Some individuals who engage in self-injurious behavior (SIB) also exhibit self-restraint. In the present study, a series of three functional analyses were conducted to determine the variables that maintained a participant's SIB, one without restraint items available, one with a preferred and effective form of self-restraint (an airplane pillow) available noncontingently, and one with this item delivered contingent on SIB. Results suggested that SIB was reinforced by escape and by access to self-restraint materials, self-restraint appeared to be maintained by automatic reinforcement, and continuous access to highly preferred restraint materials effectively suppressed SIB.