Discrimination of the number of sequential events by rats

Ten rats were trained to press a right lever following two successive sounds and to press a left lever following four successive sounds. Three sound sequences were used in initial discrimination training, such that reliable classification could not be based on the duration of each sound, the interval between sounds, or the total duration of the sound sequence. Classification of seven novel sound sequences suggested that the animals were either using number or the sum of sound durations in a sequence as the relevant cue. When this total sound duration was put in conflict with number, rats classified by number. The conclusion was that rats can discriminate number, even when temporal cues are controlled.     

Using Genograms as a Tool for Insight in College Counseling

The use of a genogram in counseling can provide a visual cool that stimulates insight and awareness in clients. College counseling clients struggle with many developmental, relationship, and systemic issues. Genograms, which have been proven beneficial in other settings, may also facilitate college counseling.     

Associative structure of second-order conditioning in humans

Second-order conditioning (SOC; i.e., conditioned responding to S2 as a result of S1–US pairings followed by S2–S1 pairings) is generally explained by either a direct S2→US association or by an associative chain (i.e., S2→S1→US). Previous research found that differences in responses to S2 after S1 was extinguished often depended on the nature of the S2–S1 pairings (i.e., sequential or simultaneous). In two experiments with human participants, we examined the possibility that such differences result from S1 evoking S2 during extinction of S1 following simultaneous but not sequential S2–S1 pairings. This evocation of S2 by S1 following simultaneous pairings may have paired the evoked representation of S2 with absence of the outcome, thereby facilitating mediated extinction of S2. Using sequential S2-S1 pairings, both Experiments 1 and 2 failed to support this account of how extinction of S1 reduced responding to S2. Experiment 1 found that extinguishing S1 reduced responding to S2, while extinguishing S2 had little effect on responses to S1, although forward evocation of S1 during extinction of S2 paired the evoked representation of S1 with absence of the outcome. In Experiment 2, evocation of S2 during S1 nonreinforced trials was prevented because S2–S1 pairings followed (rather than proceeded) S1-alone exposures. Nevertheless, responding to S2 at test mimicked S1 responding. Responding to S2 was high in the context in which S1 had been reinforced and low in the context in which S1 had been nonreinforced. Collectively, these experiments provide additional support for the associative-chain account of SOC.     

Symmetrical and asymmetrical sources of variance in temporal generalization

Ten rats were trained in a temporal generalization task (the peak procedure) with variations in the time of reinforcement, the intertrial interval, and the mean and variance of the duration of nonfood trials. There were three types of asymmetry in the temporal generalization gradients: positive skew, secondary rise, and positive asymptote. Asymmetrical gradients can occur as a result of asymmetrical sources of variance, multiplicative combinations of symmetrical sources of variance, and effects of anticipation of the end of a trial and the conditions of the next trial. Ten additional rats were trained with a single time of reinforcement, a limited time of reinforcement availability, long and fixed durations of nonfood trials, and a nonresponse requirement for ending a trial. These conditions markedly reduced all asymmetrical sources of variance and led to very symmetrical gradients. These results demonstrate that none of the asymmetrical sources of variance necessarily has a substantial influence on observed temporal generalization gradients.     

Literature Circles: Reducing Reading Stress

The concept of literature circles is now familiar in American and Australian literature about reading, but it does not as yet have great currency in this country. This article by Charlotte Keefe may do much to change this as it very lucidly explains the benefits of and teaching strategies underlying the use of literature circles. As Charlotte points out, they may do much to alleviate those of children's problems with reading which stem from not seeing the point and deriving little pleasure from the experience.     

Development and Evaluation of an Inquiry-Based Elementary Science Teacher Education Program Reflecting Current Reform Movements

The National Science Education Standards (National Research Council 1996, National science education standards. Washington, DC: National Academy Press) and various other national and state documents call for teachers who possess science content knowledge, employ an inquiry approach in teaching, and engage in reflective practices. This paper describes a rationale for choosing particular recommendations to implement and how we incorporated those as we revised our elementary science education program. An analysis of the impact of the reformed inquiry-based content courses revealed that students who take more than one reformed content course improve their science content knowledge and efficacy towards teaching science significantly more than students who take fewer courses.     

Income Level, Gender, Ethnicity, and Household Composition as Predictors of Children''s School-based Competence

In the United States, being black, male, or growing up in a low-income and/or single-parent household have all been identified as risk factors for maladjustment during childhood. Interpretation of these findings is, however, often difficult because of the well-known associations among these variables. In the present study, we compared predictions of 3 different forms of children's competence from each of these 4 variables. In a sample of 868 black and white elementary school children from 2-parent and mother-headed 1-parent homes, we studied 3 aspects of school-based competence: conduct, peer relations, and academic achievement. Results showed that although the independent variables accounted for different amounts of variance in each domain of competence, income level and gender were better overall predictors of children's competence in conduct and peer relations than were ethnicity or household composition. Income level and ethnicity were better overall predictors of academic achievement than were gender or household composition, although each of the 4 variables made a significant contribution. Overall, income level and gender were thus the strongest predictors of children's competence. Black children were, however, more likely than white children to live in low-income homes. Our results thus highlighted some correlates of the unequal distribution of economic resources among black and white children growing up in the United States today.     

Serial pattern learning of temporal intervals

The problem was to determine how rats adjust the times of their lever responses to repeating sequences of interfood intervals. In Experiment 1, rats were trained on an interval schedule of reinforcement with a 12-element Fleshler-Hoffman series with a mean of 60 sec; the order was as follows: ascending, random with repetition, random with replacement, random without replacement. In Experiment 2, rats were trained with a 10-element ascending or descending series (from 2⁰ to 2⁹ sec), and in a ramp procedure in which these intervals increased and then decreased repeatedly. In the ascending, descending, and ramp conditions (but not in the random conditions), postreinforcement pause (PRP) was a function of the interval. PRP was most highly correlated with an interval later in the series. Theories of conditioning and timing based on the averaging of past experience must be modified to account for such anticipatory behavior.     

An Innovative Course Featuring Action Research Integrated with Unifying Science Themes

In this article, we describe an innovative capstone course for preservice K-8 teachers integrating action research and a unifying theme in science (AAAS in Science for all Americans. Oxford University Press, New York, 1989; NRC in National science education standards. National Academy Press, Washington, DC, 1996). The goals of the capstone course are to increase student knowledge of the unifying theme, improve written communication skills, and introduce students to educational research. We provide evidence that each of these goals is met. Student growth in theme knowledge is demonstrated through concept maps, questionnaires, and previously reported assessments. Improved writing ability is demonstrated using the spelling and grammar checking feature of Microsoft Word. The analysis of action research reports demonstrates that students are able to connect their action research project results to previous research.