Using the FORTH language in real-time computer applications

The FORTH computer language is described, with emphasis on aspects relevant to its use in the real-time control of psychological experiments via microcomputers. Among FORTH’s advantages are speed, compactness, and flexibility. Potential disadvantages include unusual syntax and lack of file-oriented disk access. Two sample FORTH-based systems are described.     

Titration of schedule parameters by pigeons

Pigeons were tested in a computer-controlled two-key chamber. A standard (nonchanging) schedule of reinforcement was in force on one key, and an adjusting schedule on the other. The schedules were available concurrently after each reinforcement, but after the first peck on either key (the choice peck), the schedule on the other key was made inoperative. The parameter of the adjusting schedule was decreased when the standard schedule was chosen and increased when the adjusting schedule was chosen. The standard schedule was changed only between sessions. Fixed intervals and fixed ratios were used as standard schedules, and intervals and ratios were used as adjusting schedules. When standard and adjusting schedules were of the same type, median parameters on the adjusting key equalled those of the standard schedules, at four values of each standard schedule. For four of five birds, and for the group median, similar curves could be plotted through the indifference points obtained from a standard ratio with an adjusting interval, and from a standard interval with an adjusting ratio. These points showed consistent individual differences, but they could be predicted by assuming that the median time from the choice peck to reinforcement should be the same on both keys. This is equivalent to treating the schedule as a concurrent chain and assuming that Herrnstein's quantitative law of effect applies.     

Discrimination of polymorphous stimulus sets by pigeons

Pigeons were trained to perform a visual discrimination between stimulus sets in which the presence of any two of three positive features made a stimulus positive, while any two of three negative features made it negative (there were thus three different positive and three different negative stimuli). After training, the birds were exposed to test stimuli that contained either all three positive or all three negative features. In Experiment I three pigeons were successfully trained by a successive method, and subsequently responded to the test stimuli as though they were positive or negative respectively. In Experiment II four pigeons were trained by a simultaneous method. Three learned the discrimination and generalized appropriately to the test stimuli, but they showed no preference between positive test and positive training stimuli, nor any consistent difference in speed of response to them; and similar results were found for negative stimuli. It is argued from this that the pigeons learned to respond to the stimuli as patterns (configurations of features) rather than to the constituent features, but that they generalized to the test stimuli by using the common features. The experiments show that pigeons could in principle learn to discriminate natural polymorphous classes (such as “pigeon” or “person”) without using any single feature, but neither the present experiments nor earlier ones demonstrating discriminations of such natural classes establish that pigeons make use of polymorphous concepts in the same way as people.     

What's Fair When a Child Testifies?1

Undergraduates (N = 385) watched a 2-hr, videotaped, mock trial of a child sexual abuse case. The child testified in open court, with a barrier between the child and the defendant, or via closed circuit television. Students enacted the role of a juror, sibling of the defendant, or sibling of the mother of the victim. The judge either did or did not warn jurors that the barrier or video should not be considered evidence of the defendant's guilt. Use of the barrier or video did not influence guilty votes, the credibility of witnesses, nor the perceived fairness of the trial for jurors. Siblings of the defendant perceived these procedures to be biased and their use as unfair. Increased publicity about the use of barriers and closed-circuit television when children testify is recommended to reduce objections to these procedures.     

The relation of cultural context and social relationships to career development in middle school

This study examined the role of supportive relationships (i.e., family, teacher, and peer) and agency (i.e., self-efficacy, motivation, and goal-setting orientation) on three outcomes: academic grades, distress, and career decidedness. Data from 588 middle school youth from Northern (N = 322) and Southern (N = 266) Italy were analyzed using path modeling. Results indicated that across gender and region, agency was consistently related to academic grades and career decidedness. However, the role of supportive relationships was found to differ across gender and region. For both boys from Northern Italy and girls from Southern Italy, the impact of family support on academic grades and career decidedness was mediated by agency. For girls from Northern Italy, family support related directly to academic grades and career decidedness. Implications for practice were described.     

The Effects of Experimentally Induced Rumination, Positive Reappraisal, Acceptance, and Distancing When Thinking About a Stressful Event on Affect States in Adolescents

The current study compares the effects of experimentally induced rumination, positive reappraisal, distancing, and acceptance on affect states in adolescents aged 13–18. Participants (N = 160) were instructed to think about a recent stressful event. Next, they received specific instructions on how to think about that event in each condition. Manipulation checks revealed that the manipulations were successful, except for acceptance. The two most reported events were “a fight” and “death of loved one”. Results showed that positive reappraisal (i.e., thinking about the benefits and personal growth) caused a significantly larger increase in positive affect and decrease in negative affect compared to rumination, distancing, and acceptance. Current findings implicate that positive reappraisal seems an adequate coping strategy in the short-term, and therefore could be applied in interventions for youth experiencing difficulties managing negative affect. Future research should focus on long-term effects of these cognitive strategies and on more intensive training of acceptance.     

Associations between personality traits and psychological well-being across time in middle adulthood

Associations of personality traits with psychological well-being (PWB) were analyzed across ages 33–50 as part of an ongoing Finnish longitudinal study (initial N = 369). Bivariate latent growth curve analyses indicated that a low initial level of neuroticism (.75) and high extraversion (.55) correlated strongly with a high level of PWB. Moreover, a high level of conscientiousness, openness, and agreeableness also correlated significantly with PWB. The change factor was significant only for openness: the higher the initial level of PWB, the higher the increase in openness from age 33–50. In comparison with emotional well-being, indicated by general life satisfaction, the associations of the personality traits with PWB were significantly stronger for neuroticism, extraversion, and openness.     

Randomized clinical trial of adapted mindfulness-based stress reduction versus group cognitive behavioral therapy for heterogeneous anxiety disorders

ObjectiveTo compare a mindfulness-based intervention with cognitive behavioral therapy (CBT) for the group treatment of anxiety disorders.MethodOne hundred five veterans (83% male, mean age = 46 years, 30% minority) with one or more DSM-IV anxiety disorders began group treatment following randomization to adapted mindfulness-based stress reduction (MBSR) or CBT.ResultsBoth groups showed large and equivalent improvements on principal disorder severity thru 3-month follow up (ps < .001, d = ?4.08 for adapted MBSR; d = ?3.52 for CBT). CBT outperformed adapted MBSR on anxious arousal outcomes at follow up (p < .01, d = .49) whereas adapted MBSR reduced worry at a greater rate than CBT (p < .05, d = .64) and resulted in greater reduction of comorbid emotional disorders (p < .05, d = .49). The adapted MBSR group evidenced greater mood disorders and worry at Pre, however. Groups showed equivalent treatment credibility, therapist adherence and competency, and reliable improvement.ConclusionsCBT and adapted MBSR were both effective at reducing principal diagnosis severity and somewhat effective at reducing self-reported anxiety symptoms within a complex sample. CBT was more effective at reducing anxious arousal, whereas adapted MBSR may be more effective at reducing worry and comorbid disorders.     

Evaluation of a counselling skills course for health professionals

A counselling skills course run by a London hospital for 11 health professionals was evaluated. The course covered family counselling skills and child management techniques. Qualitative and quantitative measures were used at five times of testing over a period of 10 months. It was found that participants improved self-perceptions of their counselling ability, increased their knowledge of counselling theories, and considered the course to be helpful in their subsequent work with families. There was no significant change in trainees' self-concept scores. Regular supervision was regarded as helpful in consolidating skills and exploring aspects of practice in a safe environment. Issues relating to evaluation research are discussed.