Transitional and steady-state choice behavior under an adjusting-delay schedule

Twelve rats made repeated choices on an adjusting-delay schedule between a smaller reinforcer (A) that was delivered immediately after a response and a larger reinforcer (B) that was delivered after a delay which increased or decreased by 20% depending on the subject's choices in successive blocks of trials. In two phases of the experiment (100 sessions and 40 sessions), reinforcer sizes were selected which enabled theoretical parameters expressing the rate of delay discounting and sensitivity to reinforcer size to be estimated from the ratio of the indifference delays obtained in the two phases. Indifference delays, calculated from adjusting delays in the last 10 sessions of each phase, were shorter when the sizes of A and B were 14 and 25 μl of a 0.6 M sucrose solution than when they were 25 and 100 μl of the same solution. The ratio of the indifference delays was significantly smaller than that predicted on the basis of an assumed linear relation between reinforcer size and instantaneous reinforcer value, consistent with a previous proposal that this relation may be hyperbolic in form. Estimates of the rate of delay discounting based on the ratio of the two indifference delays (mean, 0.08 s(-1)) were similar to values obtained previously using different intertemporal choice protocols. Estimates of the size-sensitivity parameter (mean 113 μl) were similar to estimates recently derived from performance on progressive-ratio schedules. In both phases of the experiment, adjusting delays in successive blocks of trials were analyzed using the Fourier transform. The power spectrum obtained from individual rats had a dominant frequency that corresponded to a period of oscillation of the adjusting delay between 30 and 100 trial blocks (mean, 78). Power in the dominant frequency band was highest in the early sessions of the first phase and declined with extended training. It is suggested that this experimental protocol may have utility in neurobehavioral studies of intertemporal choice.     

Strengthening Connections: Functional Connectivity and Brain Plasticity

The ascendancy of functional neuroimaging has facilitated the addition of network-based approaches to the neuropsychologist’s toolbox for evaluating the sequelae of brain insult. In particular, intrinsic functional connectivity (iFC) mapping of resting state fMRI (R-fMRI) data constitutes an ideal approach to measuring macro-scale networks in the human brain. Beyond the value of iFC mapping for charting how the functional topography of the brain is altered by insult and injury, iFC analyses can provide insights into experience-dependent plasticity at the macro level of large-scale functional networks. Such insights are foundational to the design of training and remediation interventions that will best facilitate recovery of function. In this review, we consider what is currently known about the origin and function of iFC in the brain, and how this knowledge is informative in neuropsychological settings. We then summarize studies that have examined experience-driven plasticity of iFC in healthy control participants, and frame these findings in terms of a schema that may aid in the interpretation of results and the generation of hypotheses for rehabilitative studies. Finally, we outline some caveats to the R-fMRI approach, as well as some current developments that are likely to bolster the utility of the iFC paradigm for neuropsychology.     

Prospective Associations Between Peer Victimization and Internalizing Symptoms in Adolescence: The Protective Role of Hope

Youth who experience aggression at the hands of peers are at an increased risk for a variety of adjustment difficulties, including depressive and anxiety symptoms and lower self-esteem. The links between peer victimization and internalizing problems are robust, but less work has been done to identify individual-level protective factors that might mitigate these outcomes. The current study investigated whether hope served as a moderator of the prospective links from peer victimization to depressive and anxiety symptoms and self-esteem during adolescence. Participants included 166 high school students (64% female; 88% Black/African American). Youth completed self-report measures at three different time points across the Spring semester of an academic year. As predicted, hope interacted with peer victimization to predict changes in depressive and anxiety symptoms over the course of the semester. That is, for youth with low levels of hope, peer victimization predicted more stable patterns of depressive and anxiety symptoms. For adolescents with average levels of hope, however, peer victimization did not influence anxiety and depressive symptoms over time. Finally, for adolescents with high levels of hope, peer victimization predicted greater decreases in anxiety symptoms over time. Hope did not interact with peer victimization to predict self-esteem. Rather, hope uniquely predicted higher levels of self-esteem, whereas peer victimization uniquely predicted lower levels of self-esteem. The current study provides initial support for the notion that hope can serve as a protective factor among youth who are victims of peer aggression.

     

Adversariality in Argumentation: Shortcomings of Minimal Adversariality and A Possible Reconstruction

Argumentation - Minimal adversariality consists in the opposition of contradictory conclusions in argumentation, and its usual metaphorical expression as a game between combating arguers has seen...     

When attention is intact in adults with ADHD

Is covert visuospatial attention—selective processing of information in the absence of eye movements—preserved in adults with attention-deficit/hyperactivity disorder (ADHD)? Previous findings are inconclusive due to inconsistent terminology and suboptimal methodology. To settle this question, we used well-established spatial cueing protocols to investigate the perceptual effects of voluntary and involuntary attention on an orientation discrimination task for a group of adults with ADHD and their neurotypical age-matched and gender-matched controls. In both groups, voluntary attention significantly improved accuracy and decreased reaction times at the relevant location, but impaired accuracy and slowed reaction times at irrelevant locations, relative to a distributed attention condition. Likewise, involuntary attention improved accuracy and speeded responses. Critically, the magnitudes of all these orienting and reorienting attention effects were indistinguishable between groups. Thus, these counterintuitive findings indicate that spatial covert attention remains functionally intact in adults with ADHD.     

Daily Peer Hassles and Non-Suicidal Self-Injury in Adolescence: Gender Differences in Avoidance-Focused Emotion Regulation Processes

This study aimed to examine the mediating role of rumination, experiential avoidance, dissociation and depressive symptoms in the association between daily peer hassles and non-suicidal self-injury among adolescents. Additionally, this study explored gender differences in these associations and tested whether the proposed model was invariant across genders. The sample consisted of 776 adolescents, of them 369 are males (47.6%) and 407 are females (52.4%), aged between 12 and 18 years old from middle and high schools in Portugal. Participants completed self-report questionnaires to assess daily peer hassles, rumination in its severe component (i.e., brooding), experiential avoidance, dissociation, depressive symptoms and non-suicidal self-injury. Path analysis showed that daily peer hassles indirectly impact on non-suicidal self-injury through increased levels of brooding, experiential avoidance, dissociation, and depressive symptoms. Results indicated significant gender differences in mean scores and path analysis. Male adolescents were more likely to engage in brooding and experiential avoidance in response to external distress (particularly, daily peer hassles), whereas female adolescents were more likely to engage in non-suicidal self-injury in response to internal distress (particularly, depressive symptoms). These findings suggest relevant preventive and intervention actions to address emotion dysregulation in adolescence, by teaching them acceptance and mindfulness skills as a way of coping with stressful experiences and internal distress.     

Assessing Emotional Abuse Victimization and Perpetration: A Multi-Theoretical Examination

Criminological theories traditionally used to account for crime and deviance have now been applied to explain physical intimate partner violence (IPV). However, little research has examined whether these theories can also account for emotional abuse victimization and perpetration in intimate relationships. Such an endeavor is important because one important requirement for evaluating theory is the exploration of core propositions with different types of behaviors and, of course, testing this social problem in a theoretical lens will inform health professionals and others to identify correlates that may help them create preventative solutions to reduce or end this problem. Therefore, the purpose of this study is to examine the efficacy of self-control, social learning, and strain theories to explain emotional abuse victimization and perpetration. Using a sample of college students from two public universities (N = 434), results show variables derived from general strain theory better predicted emotional abuse victimization and perpetration than self-control or social learning. Limitations, as well as directions for future research, are discussed.