Recommended housing conditions and test procedures can interact to obscure a significant experimental effect

Routine animal husbandry variables, such as group housing of mice and the order of testing of cagemates, are currently viewed to be essentially neutral with respect to the outcome of most, if not all, animal-based experiments, including those that utilize behavioral measurements. During the course of experiments that have utilized the elevated plus-maze to examine the ability of a bacterial challenge of mice to induce anxiety-like behavior, due to the activation of various cytokine pathways, we followed the recommendation of laboratory animal care staff to house the mice in pairs. When we tested the members of the pairs successively, it was found, for the first experimental set, that the behavior that reflects anxiety (time in closed arms) of the first-tested animal differed from that of the second-tested animal for both the experimental and the control animals and, critically, that these changes were in the opposite directions for the controls and the experimental animals, thus obscuring the effect of the experimental manipulation. A second, independent experimental set also obtained a significant effect for the order of testing effect in the bacterial-challenged group, but not in the saline control group, although a similar trend was evident in this group as well. These results indicate that special care should to be taken in implementing housing recommendations and that preliminary tests may be necessary to ensure that housing conditions do not interact with tests of the phenomenon under experimental investigation.     

Reliability of looking time

Twenty-eight college students viewed two sets of 30 color photographs each under instructions to look at each picture for as long as they wished. Equal thirds of the stimuli in each set were selected from high, middle, and low complexity levels. The sets were presented 7–10 weeks apart. The results indicated significant between- and within-session correlations that were not dependent on stimulus complexity. It was suggested that the findings were indicative of a consistency in either the rate at which Ss process information or the amount of information they process or both.     

The relationship between creativity and psychosis-proneness

One-hundred and fifteen undergraduates were repeatedly administered a battery measuring schizotypal personality type and creativity (remote associations). Principal Components Analysis found a two-factor model to be most parsimonious. The pattern of results suggests that magical ideation and perceptual aberration items are represented by one factor and suspiciousness by the second. Analysis of consistent versus inconsistent high scorers on the schizoptypia measure indicated that inconsistent high scorers on the suspiciousness factor scored significantly higher than consistent high scorers on the creativity measure.     

The role of dynamic information in the recognition of unfamiliar faces

The effects of movement on unfamiliar face recognition were investigated. In an incidental learning task, faces were studied either as computer-animated (moving) displays or as a series of static images, with identical numbers of frames shown for each. The movements were either nonrigid transformations (changes in expression) or rigid rotations in depth (nodding or shaking). At test, participants saw either single, static images or moving sequences. Only one experiment showed a significant effect of study type, in favor of static instances. There was no additional advantage from studying faces in motion in these experiments, in which both study types showed the same amounts of information. Recognition memory was relatively unaffected by changes in expression between study and test. Effects of viewpoint change were large when expressive transformations had been studied but much smaller when rigid rotations in depth had been studied. The series of experiments did reveal a slight advantage for testing memory with moving compared with static faces, consistent with recent findings using familiar faces. Future work will need to examine whether such effects may also be due to the additional information provided by an animated sequence.     

Implicit learning of complex structures: active adaptation and selective processing in acquisition and application

Subjects exposed to members of a structured domain become sensitive to the general structure of that domain, even when they are unaware that the domain has such structure (e.g., Reber, 1993). Numerous investigators have attempted to characterize this learning as unselective in acquisition and automatic in application. However, we contend that this characterization miscasts the fundamental nature of learning. In a series of experiments, we demonstrate that what subjects learn implicitly about the structure of a domain critically depends on decisions they make about how to organize the structural components. Similarly, the application of knowledge gained implicitly is not stable, but may be selected or even created under the demands of the test task. We conclude that implicit learning, just like explicit learning, proceeds through active organization of the stimulus complex, rather than by passively absorbing any level of structure. We propose a synthesis, in which learning, with and without awareness, is understood through a common set of principles.     

Does the Gun Pull the Trigger? Automatic Priming Effects of Weapon Pictures and Weapon Names

More than 30 years ago, Berkowitz and LePage (1967) published the first study demonstrating that the mere presence of a weapon increases aggressive behavior. These results have been replicated in several contexts by several research teams. The standard explanation of this weapons effect on aggressive behavior involves priming; identification of a weapon is believed to automatically increase the accessibility of aggression-related thoughts. Two experiments using a word pronunciation task tested this hypothesis. Both experiments consisted of multiple trials in which a prime stimulus (weapon or nonweapon) was followed by a target word (aggressive or nonaggressive) that was to be read as quickly as possible. The prime stimuli were words in Experiment 1 and pictures in Experiment 2. Both experiments showed that the mere identification of a weapon primes aggression-related thoughts. A process model linking weapons as primes to aggressive behavior is discussed briefly.     

The Evaluation of Parental Fitness in Termination of Parental Rights Cases: A Functional-Contextual Perspective

This article highlights issues involved in carrying out evaluations for termination of parental rights cases and suggests caution for mental health professionals doing such evaluations. It argues that current models of parenting that come from the child development and child maltreatment fields are too narrow in their focus to act as a foundation for such evaluations and are often based on research with select groups in our society making them open to bias. Similarly, it is argued that traditional assessment measures are limited in their utility for responding to the kinds of relational and basic care questions asked in such evaluations. A functional-contextual model is offered as an alternative with examples of potentially useful measurement strategies. With such a frame as a starting point, the field might progress to providing more useful information to courts. Future research directions to improve this practice arena are discussed.     

Conflict-Resolution Training and Middle School Students' Integrative Negotiation Behavior

This study examined the impact of conflict-resolution training on students' use of distributive and integrative negotiating procedures. In a midwestern, suburban middle school, 176 students (grades 6 through 9) participated in the study. Students were placed in a negotiation situation involving the buying and selling of commodities in which they could adopt a distributive (maximize own outcomes) or an integrative (maximize joint outcomes) negotiation approach. There were no significant differences between males and females or among students in the 6th, 7th, 8th, and 9th grades. The results of this study indicated that conflict-resolution and peer-mediation training resulted in the middle school students increasing their use of integrative negotiations and the positiveness of students' attitudes toward conflict.     

A fuzzy trace analysis of categorical inferences and instantial associations as a function of retention interval

Two experiments on children's inferences and associative memory provided a test of predictions from fuzzy-trace theory. Specifically, it was expected that gist-based false recognitions would increase with age and that false recognitions would be uncorrelated with verbatim memory. In Experiment 1, children in Grades 1 through 5 heard lists of category labels, clustered instances from categories, and individual instances. On an immediate test, children indicated whether or not they had previously heard a series of individually presented test words. This list consisted of old words, new words, or words that were categorically or semantically related to the studied word clusters. Children made more false recognition errors for instances than for categories. Verbatim memory and inferences were unrelated. In Experiment 2, the effect of a test delay on categorical inferences and associated instances was examined with children in Grades 1 to 6. With delay, false recognition of associated instances declined for children at all grade levels. In contrast, categorical inferences increased with delay for older children. Verbatim memory and inferences were uncorrelated under immediate and 1-day delay conditions, but there were some low but significant correlations across grades under the 7-day delay. The results of the two experiments are interpreted as supporting fuzzy-trace theory.