A comparison of operant licking and lever pressing in the rat

Two groups of rats were trained on a signaled, free-operant, avoidance procedure to lick or to lever press in order to avoid shock while water-deprived or satiated and, in the case of licking, while ingesting deionized water, isotonic saline, or 10% sucrose. The most effective avoidance licking occurred while the rats were water-deprived and ingesting 10% sucrose. Water deprivation level had no effect on lever pressing for shock avoidance. Two other groups of rats were operantly conditioned to lick or to lever press for food pellets while waterdeprived or satiated and, in the case of licking, while ingesting deionized water or 10% sucrose. The most effective licking for food reinforcement occurred while the rats were water-deprived and ingesting 10% sucrose. Water deprivation level had no effect on lever pressing for food reinforcement. The data indicated that effective operant licking must be supported by factors related to water regulation and taste palatability.     

Blocking of incidental information in young children

Methods of increasing learning efficiency through a blocking technique were examined in young children. An experimental group of children was trained on an initial task with one relevant dimension, followed by redundancy training in which an incidental dimension also became relevant. A control group given only redundancy training was compared to this group to test how much the experimental subjects blocked or screened out the incidental dimension. In order to increase blocking, three methods were used: a preset transfer problem, an overtraining on the initial task, and a delay following training. The most important finding was increased blocking through the Preset Condition. Overtraining and Delay Conditions had no effect. In addition, more slow learners on the initial task learned about the incidental dimension than fast or intermediate learners. Also, fewer subjects given form on the initial task learned about the incidental dimension than those given color. The Combined Blocking, Delay, and Overtraining group showed partial blocking, while the Preset group demonstrated complete blocking. No developmental differences occurred. The results were interpreted using a modification of Trabasso and Bower's attention model (Attention in learning: Theory and research. New York: Wiley, 1968).     

The contribution of school experience to students' resilience following a terror-related homicide

Schools have a significant effect on students' development, and serve as important social agencies for interventions for students facing disasters. However, little is known about the effect of students' school experience itself on their resilience when facing extreme negative events. The present study focused on students who were exposed to terror-related homicide with the aim of investigating the contribution of school climate resources to their resilience. Since resilience is associated not only with fewer negative outcomes, but also with positive change, the contribution of schools was studied as both inhibiting post-traumatic stress symptoms (PTS) and enhancing post-traumatic growth (PTG). A mixed-methods research design was used. The participants included 117 (52% girls) high school students (mean age = 14.54; SD = 1.49). Twenty-five of them were interviewed in addition to responding to the research questionnaires. Different aspects of the school climate were found to be associated with students' PTS and PTG, yielding two overarched factors explaining the school's role as a protective resource: sheltering and supporting. The former is associated with fewer PTS and the latter with higher PTG. The use of different resources for different forms of resilience is discussed.