Parallel neural systems for classical conditioning: Support from computational modeling

Classical conditioning has been explained by two main types of theories that postulate different learning mechanisms. Rescorla and Wagner (1972) put forth a theory in which conditioning is based on the ability of the US to drive learning through error correction. Alternatively, Mackintosh (1973) put forth a theory in which the ability of the CS to be associated with the unconditioned stimulus is modulated. We have proposed a reconciliation of these two mechanisms as working in parallel within different neural systems: a cerebellar system for US modulation and a hippocampal system for CS modulation. We developed a computational model of cerebellar function in eyeblink conditioning based on the error correction mechanism of the Rescorla-Wagner rule in which learningrelated activity from the cerebellum inhibits the inferior olive, which is the US input pathway to the cerebellum (Gluck et al., 1994). We developed a computational model of the hippocampal region that forms altered representations of conditioned stimuli based on their behavioral outcomes (Gluck & Myers, 1993; Myers et al., 1995). Overall, computational modeling and empirical findings support the idea that, at least in the case of eyeblink conditioning, there may be two different neural systems: the cerebellum which mediates US-based error correction and hippocampus which alters representations of CSs.     

User-controlled photographic animations, photograph-based questions, and questionnaires: Three Internet-based instruments for measuring drivers’ risk-taking behavior

The Internet has been exploited successfully in the past as a medium for behavioral research. This paper presents a series of studies designed to assess Internet-based measures of drivers’ risk-taking behavior. First, we compared responses from an Internet sample with a traditional pencil-and-paper sample using established questionnaire measures of risk taking. No significant differences were found. Second, we assessed the validity of new Internet-based instruments, involving photographs and photographic animations, that measured speed, gap acceptance, and passing. Responses were found to reflect known demographic patterns of actual behavior to some degree. Also, a roadside survey of speeds was carried out at the locations depicted in the photographic measure of speeding and, with certain exceptions, differences between the two appeared to be constant. Third, a between-subject experimental manipulation involving the photographic animation measure of gap acceptance was used to demonstrate one application of these techniques.     

Individual differences in the mixture ratio of rotation and nonrotation trials during rotated mirror/normal letter discriminations

Mental rotation is thought to underlie the increase in response times (RTs) for deciding whether rotated letters are normal or mirrored versions. However, mental rotation predicts a linear increase in RTs, whereas the mirror/normal letter discrimination task typically produces a curved function. Recently, Kung and Hamm suggested that this curved function results from a mixture of trials in which mental rotation is employed and trials in which it is not. The mixture ratio may vary between individuals, with some individuals relying more on mental rotation than others. There is no factor in the Kung and Hamm model that reflects such individual differences. In the present study, we suggest that a possible exponent parameter could be added to the Kung and Hamm model to capture individual differences in the mixture ratio. This exponent parameter appears to capture an individual characteristic since the value obtained correlates between the mirror/normal letter task and a left/right object facing task. The development of a quantity that represents the mixture ratio will aid further testing of processes involved in the visual imagery system.     

Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): the association between deficient behavioral inhibition, attentional processes, and objectively measured activity

Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes.     

Prospective analysis of early lapse to drinking and smoking among individuals in concurrent alcohol and tobacco treatment

The aims of the current study were to examine, prospectively, (a) dynamic changes in affective state, self-efficacy, and urge in the hours before initial smoking and drinking lapses among individuals in concurrent alcohol and smoking treatment, and (b) the extent to which self-efficacy, urge to use, and/or the use of one substance predicted lapse to the other substance. Ninety-six men and women recruited for a clinical trial of concurrent alcohol and tobacco treatment were eligible for inclusion. Only data from those who experienced an initial lapse to drinking (n=29) or smoking (n=32) were included. Two outpatient substance abuse clinics provided concurrent alcohol and smoking treatment on a weekly basis for three months. Ecological Momentary Assessment (EMA) methods were employed over a 28-day monitoring period to assess antecedents to first drink, and a 14-day monitoring period was examined for initial smoking lapses. Baseline and EMA measures of positive and negative affect, alcohol/smoking urge, alcohol/smoking abstinence self-efficacy, nicotine withdrawal, and quantity/frequency of alcohol and tobacco use were examined as lapse predictors. Analyses of EMA ratings controlled for the corresponding baseline measure. Smoking lapse among individuals in concurrent alcohol and tobacco treatment was foreshadowed by higher urges to smoke, lower positive mood, and lower confidence to resist smoking. Drinking lapse was preceded by lower confidence to resist smoking, but only among individuals who reported recent smoking. Concurrent alcohol and smoking treatment should focus on the enhancement of abstinence self-efficacy, positive mood, and the curbing of urges in order to offset lapse risk.     

Dividing attention lowers children's but increases adults' false memories

The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a divided attention task. The results showed that divided attention affected children's and adults' false memory levels differently but did not alter true memory differently. Our results revealed a developmental shift in that divided attention lowered children's false memory rates but increased adults' false memory rates, regardless of the nature of the material (i.e., neutral or negative). Our study indicates that manipulations that target conscious processing (e.g., divided attention) result in marked qualitative and quantitative differences between children's and adults' false memories but not true memories.     

Ethical Assurance Statements in Political Science Journals

Many journals in the physical sciences require authors to submit assurances of compliance with human subjects and other research ethics standards. These requirements do not cover all disciplines equally, however. In this paper we report on the findings of a survey of perceptions of ethical and managerial problems from journal editors in political science and related disciplines. Our results show that few journals in political science require assurance statements common to journals for other scientific disciplines. We offer some reasons for this as well as some recommendations for implementing ethical assurance safeguards for political science.     

Perceived unfairness and employee health: a meta-analytic integration

A growing body of research has suggested that the experience of injustice, psychological contract breach, or unfairness can adversely impact an employee's health. We conducted a meta-analysis to examine the effects of unfairness perceptions on health, examining types of fairness and methodological characteristics as moderators. Results suggested that perceptions of unfairness were associated with indicators of physical and mental health. Furthermore, psychological contract breach contributed to the prediction of strain-related indicators of health above and beyond that accounted for by injustice alone.     

Anger and postcombat mental health: Validation of a brief anger measure with U.S. Soldiers postdeployed from Iraq and Afghanistan

The involvement of anger in the psychological adjustment of current war veterans, particularly in conjunction with combat-related posttraumatic stress disorder (PTSD), warrants greater research focus than it has received. The present study concerns a brief anger measure, Dimensions of Anger Reactions (DAR), intended for use in large sample studies and as a screening tool. The concurrent validity, discriminant validity, and incremental validity of the instrument were examined in conjunction with behavioral health data for 3,528 treatment-seeking soldiers who had been in combat in Iraq and Afghanistan. Criterion indices included multiple self-rated measures of psychological distress (including PTSD, depression, and anxiety), functional difficulties (relationships, daily activities, work problems, and substance use), and violence risk. Concurrent validity was established by strong correlations with single anger items on 4 other scales, and discriminant validity was found against anxiety and depression measures. Pertinent to the construct of anger, the DAR was significantly associated with psychosocial functional difficulties and with several indices of harm to self and to others. Hierarchical regression performed on a self/others harm index found incremental validity for the DAR, controlling for age, education, military component, officer rank, combat exposure, PTSD, and depression. The ability to efficiently assess anger in at-risk military populations can provide an indicator of many undesirable behavioral health outcomes. (PsycINFO Database Record (c) 2012 APA, all rights reserved).