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.     

Sex,Sexual Orientation,and Sexism: What Influence Do These Factors Have on Verdicts in a Crime-of-Passion Case?

ABSTRACT

This study investigated the influence of defendant sex, sexual orientation, and participant sex on perceptions of a crime-of-passion. An online sample of 458 individuals read a scenario describing a homicide and provided judgments of verdict, sentence length, legal elements, and sexism. We hypothesized heterosexual female defendants would most likely receive a verdict of manslaughter, be found less guilty, and receive shorter sentences. We were also interested in whether benevolent sexism would contribute to defendant culpability decisions. Lastly, perceptions of legal elements for manslaughter (e.g., great provocation) and murder (e.g., intentionality of actions) were explored. Results demonstrated heterosexual female defendants were less guilty and received the shortest sentences. Also, heterosexual defendants were most likely to meet the manslaughter legal elements. Benevolent sexism contributed significantly to guilt perceptions.     

Effects of Offenders' Age and Health on Sentencing Decisions

ABSTRACT

Two experiments investigated the effects of age and health on mock judges' sentencing decisions. The effects of these variables on length of prison sentence were examined in the context of offense severity and prior convictions. Experiment 1 involved a violent crime. Main effects were observed for age, health, offense severity and prior convictions. There was also an age by offense severity interaction. Experiment 2 involved a child sexual abuse case. Main effects were observed for health, offense severity, and prior convictions. In addition, an age by offense severity by prior convictions interaction effect was found. Thus, across both experiments, the age leniency effect was moderated by legal factors, suggesting that extra-legal factors affect sentencing in the context of legal factors. Further, for both offenses, offenders in poor health received shorter sentences than offenders in good health, suggesting that health deserves further research attention as an extra-legal variable.     

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 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.