Differential acquisition of lever pressing in inbred and outbred mice: comparison of one-lever and two-lever procedures and correlation with differences in locomotor activity

Recent progress in mouse genetics has led to an increased interest in developing procedures for assessing mouse behavior, but relatively few of the behavioral procedures developed involve positively reinforced operant behavior. When operant methods are used, nose poking, not lever pressing, is the target response. In the current study differential acquisition of milk-reinforced lever pressing was observed in five inbred strains (C57BL/6J, DBA/2J, 129X1/SvJ, C3H/HeJ, and BALB/cJ) and one outbred stock (CD-1) of mice. Regardless of whether one or two levers (an "operative" and "inoperative" lever) were in the operant chamber, a concomitant variable-time fixed-ratio schedule of milk reinforcement established lever pressing in the majority of mice within two 120-min sessions. Substantial differences in lever pressing were observed across mice and between procedures. Adding an inoperative lever retarded acquisition in C57BL/6J, DBA/2J, 129X1/SvJ, and C3H/HeJ mice, but not in CD-1 and BALB/cJ mice. Locomotor activity was positively correlated with number of lever presses in both procedures. Analyses of durations of the subcomponents (e.g., time to move from hopper to lever) of operant behavior revealed further differences among the six types of mice. Together, the data suggest that appetitively reinforced lever pressing can be acquired rapidly in mice and that a combination of procedural, behavioral, and genetic variables contributes to this acquisition.     

Depression and Contributors to Vocational Satisfaction in Roman Catholic Secular Clergy

A nationally selected, random sample of Roman Catholic secular (i.e., diocesan) priests was examined using the Center for Epidemiological Studies-Depression scale and an instrument developed for this study to assess contributors to priests' vocational satisfaction. In addition, a self-report inventory gathered information regarding participants' demographics as well as four categories of predictor variables (i.e., overall level of vocational satisfaction, social support, spiritual activities, physical environment). The study yielded a response rate of 45%. Secular clergy reported rates of depression approximately seven times greater than are found in the general population, and also indicated that the recent sexual abuse scandal in the Roman Catholic church had negatively affected their mood. Priests' engagement in sacramental activities contributed greatly to their vocational satisfaction, and low levels of vocational satisfaction were found to be most predictive of depression. Factors comprising priests' vocational satisfaction were External Manifestations (e.g., preaching, teaching), Internal Manifestations (e.g., prayer life, affirmation of God's call), and Social Manifestations (e.g., relationships with parishioners, appreciation from others).     

When elaboration leads to appropriation: unconscious plagiarism in a creative task

Brown and Murphy's (1989) three-stage paradigm (generation, recall-own, generate-new) was used to assess the effects of participant elaboration on rates of unconscious plagiarism in two experiments using a creative task. Following the generation phase, participants imagined and rated a quarter of the ideas (imagery elaboration), generated improvements to another quarter (generative elaboration), and listened to a quarter of the ideas again without elaboration, with the remaining ideas acting as control. A week later, participants attempted to recall their own ideas, and generate new solutions to the same cues. In Experiment 1 both forms of elaboration equally increased correct recall, and decreased plagiarism in the generate-new task. However, generative elaboration led to significantly greater plagiarism in the recall-own task, but imagery elaboration did not. Participants in Experiment 2 were encouraged not to plagiarise by means of a financial incentive. However, they showed the same pattern as seen in Experiment 1. Therefore, contrary to a simple strength account, the probability of a person plagiarising another's ideas is linked to the particular nature of the elaboration carried out on that idea, rather than its familiarity.     

Objective assessment of covert antisocial behavior: predictive validity and ethical considerations

Although less observable than the overt actions of fighting and assault, covert antisocial behaviors such as stealing and property destruction comprise an important subclass of externalizing behavior patterns, displaying considerable predictive power toward delinquency in adolescence. I discuss a laboratory paradigm for objective observation of such behaviors in children that has shown impressive concurrent and predictive validity among samples of boys with and without attention deficit hyperactivity disorder. Addressed herein are crucial questions regarding the ethics of tempting children to steal objects and small amounts of money and to deface property as well as the types of informed consent and debriefing procedures utilized in research with this paradigm. Weighing ethical considerations alongside the ability to predict delinquent behavior presents provocative issues for those interested in understanding the development of antisocial behavior.     

A mixed-handed advantage in episodic memory: A possible role of interhemispheric interaction

Recent behavioral and brain imaging data indicate that performance on explicit tests of episodic memory is associated with interaction between the left and right cerebral hemispheres, in contrast with the unihemispheric basis for implicit tests of memory. In the present work, individual differences in strength of personal handedness were used as markers for differences in hemispheric communication, with mixed-handers inferred to have increased interhemispheric interaction relative to strong right-handers. In Experiment 1, memory for words was assessed via recall or word fragment completion. In Experiment 2, memory for real-world events was assessed via recall. Results supported the hypothesis, in that mixed-handers displayed better episodic memory in comparison with strong right-handers.     

Identity and emergency intervention: how social group membership and inclusiveness of group boundaries shape helping behavior

Two experiments exploring the effects of social category membership on real-life helping behavior are reported. In Study 1, intergroup rivalries between soccer fans are used to examine the role of identity in emergency helping. An injured stranger wearing an in-group team shirt is more likely to be helped than when wearing a rival team shirt or an unbranded sports shirt. In Study 2, a more inclusive social categorization is made salient for potential helpers. Helping is extended to those who were previously identified as out-group members but not to those who do not display signs of group membership. Taken together, the studies show the importance of both shared identity between bystander and victim and the inclusiveness of salient identity for increasing the likelihood of emergency intervention.     

Factor structure and validity of the MacArthur Competence Assessment Tool-Criminal Adjudication

Examination of the available literature regarding the development of the MacArthur Competence Assessment Tool-Criminal Adjudication (MacCAT-CA) reveals 2 theoretical factor structures on which the MacCAT-CA was based: one in which 3 lower-order constructs are proposed (understanding, reasoning, appreciation) and one in which 2 higher-order constructs are proposed (competence to assist counsel and decisional competence). Confirmatory factor analyses were conducted with the MacCAT-CA's original normative sample (N = 729) to test both the relative fit of these 2 theoretical factor structures and models that combine the 2 factor structures. Analyses were also completed to examine the convergent and discriminant validity of the MacCAT-CA. Results are discussed in terms of the strengths and weaknesses of the nomothetic nature of the MacCAT-CA.     

Compatibility effects based on stimulus and response numerosity

Four choice reaction time experiments documented a stimulus-response (S-R) compatibility effect involving the numbers of stimuli and responses. In Experiment 1, the stimulus consisted of one or two tones, and the correct response was either one or two taps of a response key. Responses were much faster with a compatible S-R assignment, in which the number of taps matched the number of tones, than with an incompatible assignment in which these numbers mismatched. Experiments 2 and 3 replicated this effect, using visual stimuli and bimodal stimuli, respectively, suggesting that auditory/manual rhythmic compatibility is not essential to it. Experiment 4 showed that an analogous but smaller effect is obtained when stimuli are the digits 1 and 2. This new numerosity-based compatibility effect has general theoretical implications regarding the mechanisms responsible for compatibility effects and practical implications for interface design.     

Enhancement of auditory fear conditioning after housing in a complex environment is attenuated by prior treatment with amphetamine

Prior exposure to drugs of abuse has been shown to occlude the structural plasticity associated with living in a complex environment. Amphetamine treatment may also occlude some cognitive advantages normally associated with living in a complex environment. To test this hypothesis we examined the influence of prior exposure to amphetamine on fear conditioning in rats housed in either a standard or complex environment. Housing in a complex environment facilitated fear learning to an auditory conditioned stimulus (CS), but not to the training context, relative to animals housed singly or in a social group. Prior treatment with amphetamine eliminated this effect. These results indicate that living in a complex environment facilitates conditional freezing to an auditory CS, and that this effect is abolished by pretreatment with amphetamine.     

What is the prevalence of adult ADHD? Results of a population screen of 966 adults

To provide a better estimate of the prevalence of ADHD in adulthood, the authors complete a telephone survey of 966 randomly selected adults. They compute two diagnoses from the survey data. Participants meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for both childhood and adulthood are defined as narrow ADHD. Broad ADHD adds to that definition those meeting subthreshold criteria. Cronbach's alpha is .90 for the 18 DSM-IV symptoms in childhood and .88 when rated for current symptoms in adulthood. No one item unduly influences the reliability of the total score. The authors find similar results in separate analyses of hyperactive-impulsive and inattentive symptoms. They estimate prevalences of 2.9% for Narrow ADHD and 16.4% for Broad ADHD. Having ADHD is associated with lower levels of education and employment status. These findings suggest that adult ADHD is a common disorder associated with impaired functioning.