COMPUTER‐ASSISTED MEASUREMENT OF WOUND SIZE ASSOCIATED WITH SELF‐INJURIOUS BEHAVIOR

We evaluated an inexpensive, efficient, and noninvasive technique for measuring tissue damage produced by self‐injurious behavior (SIB). The technique involved computerized measurement of wound surface area (WSA) based on digital photographs. In Study 1, we compared photographic measurement to a more commonly used procedure, transparency measurement, in estimating WSA of 20 wound models. Results showed that both methods were reliable and that there was a high degree of correspondence between the 2 sets of measures. In Study 2, we compared photographic WSA measures to direct‐observation measures in documenting changes over time in the SIB exhibited by a woman with Prader‐Willi syndrome. Results showed that increases and decreases in observed SIB during baseline and treatment conditions corresponded with changes in WSA measures, indicating that the computer‐assisted photographic technique may be useful as a corroborative measure or as a primary measure when direct observation of SIB is not feasible.     

Effects of text messaged self-monitoring on class attendance and punctuality of at-risk college student athletes

This study examined the effects of text messaging class arrival to an academic counselor on the attendance and punctuality of 4 college student athletes. Each participant had a history of class tardiness and was considered to be at risk for academic failure. Class attendance and punctuality improved for all participants.     

Development of key-pecking, pause, and ambulation during extended exposure to a fixed-interval schedule of reinforcement

Six pigeons key-pecked under a fixed-interval (FI) 3-min schedule of food presentation. Each pigeon was studied for 200 daily sessions with 15 intervals per session (3,000 total food presentations). Analyses included the examination of latency to first peck (pause), mean rate of key pecking, and ambulation. Characterizations of stable performance were assessed across measures of behavior and evaluated using commonly employed stability criteria. Stability of response rate and pause was identified better by assessments that evaluated variability and trend, rather than just variability. Between-subject differences in rate of acquisition and terminal values of steady-state performance of pause were observed, and stable pause durations took longer to develop than did stable key-pecking rates. Relative variability in response rate and pause duration decreased as the means increased. A temporally organized pattern of key-pecking (the so-called FI scallop) developed within 50 sessions of exposure to the schedule. Overall ambulation decreased during the early sessions of exposure and further analyses showed greater rates of ambulation during the pause than after it for 4 of the 6 pigeons. Performance under the FI 3-min schedule developed relatively slowly, and key-pecking, pause, and ambulation developed at different rates.     

Concurrent-chains schedules as a method to study choice between alcohol-associated conditioned reinforcers

An extensive body of research using concurrent-chains schedules of reinforcement has shown that choice for one of two differentially valued food-associated stimuli is dependent upon the overall temporal context in which those stimuli are embedded. The present experiments examined whether the concurrent chains procedure was useful for the study of behavior maintained by alcohol and alcohol-associated stimuli. In Experiment 1, rats responded on concurrent-chains schedules with equal variable-interval (VI) 10-s schedules in the initial links. Across conditions, fixed-interval schedules in the terminal links were varied to yield 1∶1, 9∶1, and 1∶9 ratios of alcohol delivery. Initial-link response rates reflected changes in terminal-link schedules, with greater relative responding in the rich terminal link. In Experiment 2, terminal-link schedules remained constant with a 9∶1 ratio of alcohol delivery rates while the length of two equal duration initial-link schedules was varied. Preference for the rich terminal link was less extreme when initial links were longer (i.e., the initial-link effect), as has been previously reported with food reinforcers. This result suggests that the conditioned reinforcing value of an alcohol-associated stimulus depends on the temporal context in which it is embedded. The concurrent-chains procedure and quantitative models of concurrent chains performance may provide a useful framework within which to study how contextual variables modulate preference for drug-associated conditioned reinforcers.     

SAVING THE BEST FOR LAST? A CROSS-SPECIES ANALYSIS OF CHOICES BETWEEN REINFORCER SEQUENCES

Two experiments were conducted to compare choices between sequences of reinforcers in pigeon (Experiment 1) and human (Experiment 2) subjects, using functionally analogous procedures. The subjects made pairwise choices among 3 sequence types, all of which provided the same overall reinforcerment rate, but differed in their temporal patterning. Token reinforcement schedules were used in both experiments and the type of exchange schedule varied across blocks of sessions. Some conditions permitted immediate exchange of tokens for consumable reinforcers (food for pigeons, video access for humans); in other conditions, tokens accumulated and were exchanged for consumable reinforcers only at the end of the sequence. Choice patterns in the immediate-exchange conditions were generally similar across species, with both pigeons and humans preferring sequences with the shortest delay to the initial reinforcer in the series. The results are broadly consistent with models of temporal discounting expanded to include the impact of sequences of delayed reinforcers acting in parallel from the time of the choice. Preferences were less consistent with discounting models in the delayed exchange conditions. Questionnaire data gathered at the end of the experiment were consistent with prior results of questionnaire studies, but showed no straightforward relation to the observed choice patterns, urging caution in the extrapolation of results from one decision-making domain to the other.     

RELATIONS AMONG ACUTE AND CHRONIC NICOTINE ADMINISTRATION,SHORT-TERM MEMORY,AND TACTICS OF DATA ANALYSIS

Emerging evidence suggests that nicotine may enhance short‐term memory. Some of this evidence comes from nonhuman primate research using a procedure called delayed matching‐to‐sample, wherein the monkey is trained to select a comparison stimulus that matches some physical property of a previously presented sample stimulus. Delays between sample stimulus offset and comparison stimuli onset are manipulated and accuracy is measured. The present research attempted to systematically replicate these enhancement effects with pigeons. In addition, the effects of nicotine were assessed under another, more dynamic, memory task called titrating‐delay matching‐to‐sample. In this procedure, the delay between sample offset and comparison onset adjusts as a function of the subject's performance. Correct matches increase the delay, mismatches decrease the delay, and titrated delay values serve as the primary dependent measure. Both studies examined nicotine's effects under acute and chronic administration. Neither provided clear or compelling evidence of memory enhancement following nicotine administration despite reliable and systematic dose‐related changes in response latency measures. A modest dose‐related effect on accuracy was found, but the magnitude of the effect appears to be directly related to tactics of data analysis involving best‐dose analyses of a very circumscribed subset of trial types.     

Effects of a meaningful, a discriminative, and a meaningless stimulus on equivalence class formation

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A-E stimuli were abstract shapes and the C stimuli became S(D)s prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated "partial" class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes.     

EFFECTS OF A SIGNALED DELAY TO REINFORCEMENT IN THE PREVIOUS AND UPCOMING RATIOS ON BETWEEN-RATIO PAUSING IN FIXED-RATIO SCHEDULES

Domestic hens responded under multiple fixed‐ratio fixed‐ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasirandomly so that all four possible transitions occurred in each session. The delay was varied over 0, 4, 8, 16, and 32 s with fixed‐ratio 5 schedules, and over 0, 8 and 32 s with fixed‐ratio 1, 15 and 40 schedules. Main effects of fixed‐ratio value and delay duration were detected on between‐ratio pauses. Pauses were longer when the multiple‐schedule stimulus correlated with a delayed‐reinforcer component was presented, with the longest pauses occurring at the transition from a component with an immediate reinforcer to one with a delayed reinforcer. Pause durations were shortest during immediate components. Overall, both the presence or absence of a delay in the upcoming component, and the presence or absence of a delay in the preceding component affected pause length, but the upcoming delay had the larger effect. Thus changes in delay had similar effects to past reports of the effects of changes in response force, response requirement, and reinforcer magnitude in multiple fixed‐ratio fixed‐ratio schedules.     

The relationship between performance-based self-esteem and self-reported work and health behaviors among Danish knowledge workers

Since knowledge intensive work often requires self-management, one might fear that persons who are dependent on work success for self-esteem will have difficulties in finding a healthful and sustainable balance between internal needs and external demands. Accordingly, we examined to what degree work-related performance-based self-esteem (PBS) was linked to work and health behaviors in 392 knowledge workers (226 women, 166 men). In the women group, multiple binary logistic regression analyses with repeated measurements showed that the PBS score was associated with 10 of the 17 examined work and health behaviors. For men the corresponding figure was 3 of 17. In both men and women, higher PBS scores were positively associated with reports of efforts and strivings for work as well as attending work while ill. In conclusion, statistically significant relationships between PBS and work and health behaviors were more clearly visible among women than men. Whether this gender difference is dependent on the study design, or on true inherent differences between women and men, cannot be concluded with any certainty. However, persons who described themselves as being relatively more dependent on work accomplishments for a high self-esteem, as expressed by the PBS score, seem to display work behaviors that may lessen their restitution time. In addition, they also seem to be more prone to work while sick.     

Cross-contextual stability of bullying victimization: a person-oriented analysis of cyber and traditional bullying experiences among adolescents

Using a person-oriented approach the study examined whether bullying victimization at school continued into cyberspace victimization in a large sample of high school students in Lithuania (N = 1667, 58% girls), age 15-19 (M = 17.29, SD = 0.95). Three forms of traditional bullying (verbal, physical and relational) and seven forms of cyberbullying victimization through cell phones and computers were included in the analysis. The findings revealed that 35% of traditional bullying victims were also bullied in cyberspace. In particular, adolescents who experienced predominantly verbal and relational bullying at school, showed a higher risk of victimization in cyberspace a year later, while this was not observed for predominantly physical forms of traditional bullying. The findings point to the importance of a cross-contextual perspective in studies on stability of bullying victimization.