According to Botvinick's (2007) integrative account, conflict monitoring is aversive because individuals anticipate cognitive demand, whereas the revised reinforcement sensitivity theory (rRST) predicts that conflict processing is aversive because individuals anticipate aversive reinforcement of erroneous responses. Because these accounts give different reasons for the aversive aspects of conflict, we manipulated cognitive demand and the aversive reinforcement as a consequence of wrong choices in a go/no-go task. Thereby, we also aimed to investigate whether individual differences in conflict sensitivity (i.e., in trait anxiety, linked to high sensitivity of the behavioral inhibition system [trait-BIS]) represent the effects of aversive reinforcement and cognitive demand in conflict tasks. We expected that these manipulations would have effects on the frontal N2 component representing activity of the anterior cingulate cortex. Moreover, higher-trait-BIS individuals should be more sensitive than lower-trait-BIS individuals to aversive effects in conflict situations, resulting in a more negative frontal N2 for higher-trait-BIS individuals. In Study 1, with N = 104 students, and Study 2, with N = 47 students, aversive reinforcement was manipulated in three levels (within-subjects factor) and cognitive demand in two levels (between-subjects factor). The behavioral findings from the go/no-go task with noncounterbalanced reinforcement levels (Study 1) could be widely replicated in a task with counterbalanced reinforcement levels (Study 2). The frontal mean no-go N2 amplitude and the frontal no-go N2 dipole captured predicted reinforcement-related variations of conflict monitoring, indicating that the anticipation of aversive reinforcement induces variations in conflict monitoring intensity in frontal brain areas. The aversive nature of conflict was underlined by the more pronounced conflict monitoring in higher- than in lower-trait-BIS individuals.

This study examined the FRN, the P3, and individual differences in trait-BAS and trait-BIS in the context of reward expectation mismatch. A more negative FRN was predicted for higher vs. lower trait-BAS individuals and for higher vs. lower trait-BIS individuals. In the extinction-learning task, participants (N=102) chose between two response buttons to earn a maximum of points. In the acquisition phase, button 1 was continuously rewarded and button 2 was partially rewarded. In the extinction phase, one button was unexpectedly no longer rewarded. The FRN amplitude was more negative for higher vs. lower trait-BAS individuals and for lower vs. higher trait-BIS individuals within the extinction phase. The P3 was more positive in the extinction compared to the acquisition phase. Our results suggest that higher trait-BAS individuals have a more pronounced reward expectation mismatch.

The Positive and Negative Affect Schedule (PANAS) is a widely used inventory for the assessment of affect in psychology and other applied sciences. Despite its popularity, the structure of the PANAS is still under debate. On the one hand, there is evidence of the traditional 2-factor model with Positive Affect (PA) and Negative Affect (NA) as uncorrelated factors. On the other hand, a more complex structure of the PANAS has been discussed. To shed further light on the core dimensions of the PANAS, 2 studies investigated the structure of the PANAS in 2 German samples (N = 354 and N = 364, respectively) by means of confirmatory factor analysis. The factor analysis results of Study 1 for a traitlike time frame instruction suggested a suboptimal model fit for the uncorrelated 2-factor model and the 3-factor model with PA, Afraid, and Upset as factors, whereas a superior model fit occurred for a bifactor model with traitlike PA, NA, and a general 3rd factor named Affective Polarity. In Study 2, the bifactor model was replicated for a statelike PANAS time frame instruction and evidence of criterion validity was provided for PA, NA, and Affective Polarity factors in 2 sex offender subgroups and in a community sample. With Affective Polarity, we introduce an affect dimension that captures additional variance beyond PA and NA. Because of the adjectives with relevant loadings on Affective Polarity, this general factor represents an individual's orientation toward approach and withdrawal, respectively.

In the pathogenesis of nonalcoholic fatty liver disease, accumulation of lipids in hepatocytes and hepatocyte apoptosis are strongly implicated in disease progression from the potentially reversible condition of steatosis to severe acute and chronic liver injury. Acyl-CoA synthetase 5, a member of the ACSL gene family that catalyzes the activation of long-chain fatty acids for lipid biosynthesis, is the only ACSL isoform that is both, located on mitochondria and functionally involved in enterocyte apoptosis. In this study, the regulation of human ACSL5 in hepatocellular fatty acid degeneration and its involvement in hepatocyte apoptosis was investigated using models of in vitro and in vivo steatosis as well as plasmid-mediated stable gene transfer and RNAi-mediated gene silencing. ACSL5 mRNA and protein were strongly increased by uptake of dietary derived fatty acids in primary human hepatocytes, HepG2 cells and human steatotic liver. Over-expression of ACSL5 decreased HepG2 cell viability and increased susceptibility to TRAIL- and TNFalpha-, but not FAS- induced apoptosis, whereas knock down of ACSL5 reduced apoptosis susceptibility. High ACSL5 activity resulted in enhanced caspase-3/7 activity, but was not accompanied by up-regulation of death receptors, DR4, DR5 or TNF-R1. This study gives evidence that hepatocyte steatosis is associated with ACSL5 up-regulation resulting in increased susceptibility to hepatic cell death. We propose that ACSL5 could play a role in promoting fatty acid-induced lipoapoptosis in hepatocytes as important mechanism in fatty liver-related disorders.

Abstract Task- and personality-related modulations of the N2 were probed within the framework of the revised Reinforcement Sensitivity Theory (RST). Using an appetitive choice task, we investigated 58 students with extreme scores on the behavioral inhibition system and behavioral approach system (BIS/BAS) scales. The baseline-to-peak N2 amplitude was sensitive to the strength of decision conflict and demonstrated RST-related personality differences. In addition to the baseline N2 amplitude, temporal PCA results suggested two N2 components accounting for a laterality effect and capturing different N2 patterns for BIS/BAS groups with increasing conflict level. Evidence for RST-related personality differences was obtained for baseline-to-peak N2 and tPCA components in the present task. The results support the RST prediction that BAS sensitivity modulates conflict processing and confirm the cognitive-motivational conflict concept of RST.

J. A. Gray's Reinforcement Sensitivity Theory (RST) has produced a wealth of quasi-experimental studies in more than 35 years of research on personality and reinforcement sensitivity. The present meta-analysis builds on this literature by investigating RST in conflict and nonconflict reinforcement tasks in humans. Based on random-effects meta-analysis, we confirmed RST predictions of performance parameters (e.g., number of responses, reaction time) in reinforcement tasks for impulsivity- and anxiety-related traits. In studies on anxiety-related traits, the effect size variance was smaller for conflict tasks than for nonconflict tasks. A larger mean effect size and a larger variability of effect sizes were found for conflict compared to nonconflict tasks in studies on impulsivity-related traits. Our results suggest that problems with RST confirmation in reinforcement tasks are at least partly caused by insufficient statistical power of primary studies, and thus, encourage future research on RST.

The measurement of anterior electroencephalograph (EEG) asymmetries has become an important standard paradigm for the investigation of affective states and traits. Findings in this area are typically interpreted within the motivational direction model, which suggests a lateralization of approach and withdrawal motivational systems to the left and right anterior region, respectively. However, efforts to compare this widely adopted model with an alternative account-which relates the left anterior region to behavioral activation independent of the direction of behavior (approach or withdrawal) and the right anterior region to goal conflict-induced behavioral inhibition-are rare and inconclusive. Therefore, the authors measured the EEG in a sample of 93 young men during emotional imagery designed to provide a critical test between the 2 models. The results (e.g., a correlation between left anterior activation and withdrawal motivation) favor the alternative model on the basis of the concepts of behavioral activation and behavioral inhibition. In addition, the present study also supports an association of right parietal activation with physiological arousal and the conceptualization of parietal EEG asymmetry as a mediator of emotion-related physiological arousal.(PsycINFO Database Record (c) 2008 APA, all rights reserved).

The present study examined an extraversion-based extension of the integrative model of cardiovascular effort regulation by Wright and Kirby [Wright, R.A., Kirby, L.D., 2001. Effort determination of cardiovascular response: an integrative analysis with applications in social psychology. In: Zanna, M.P.(Ed.), Advances in Experimental Social Psychology, Academic Press, San Diego, CA, pp. 255-307.]. This model explains cardiovascular effort reactivity in terms of task difficulty, ability appraisal, and success importance. Aggregate measures of cardiovascular variables (alpha-adrenergic, beta-adrenergic, and cholinergic activation components) were used to measure extraversion-based differences in effort. Subjects performed a sequential letter task (n-back verbal working memory task) with four levels of difficulty. Agentic extraverts (n=10) appraised their ability and happiness as significantly higher than introverts (n=10). Introverts showed the expected shark-fin shaped pattern of effort-related cardiovascular reactivity for the alpha-adrenergic and cholinergic activation components. Effort decreased after the moderately difficult 2-back task. Results provide first evidence for an extraversion-based extension of the model and are discussed with regard to mood and resource allocation as possible mechanisms.

This study tested predictions of Gray's Reinforcement Sensitivity Theory (RST) in subgroups of sex offenders and male non-offenders using an experimental choice task consisting of a reward and a non-reward phase. In addition, RST-related psychometric measures were used. Both experimental and psychometric data were of interest to determine whether sex offenders could be reliably differentiated from non-offenders. Paraphilic (N=50) and impulse control-disordered (N=48) sex offenders showed greater sensitivity to continuous reward than male non-offenders (N=51). Impulse control-disordered sex offenders showed less behavioural adaptation under non-reward than both paraphilic sex offenders and male non-offenders. In addition, reward sensitivity, rash-spontaneous impulsivity, and anxiety measures discriminated sex offenders from male non-offenders. The results suggest that reinforcement sensitivity is a promising personality trait for differentiating subgroups of sex offenders from non-offenders. The experimental and psychometric results illustrate that predictive accuracy in forensic settings could be improved by combining several types of data.

Several lines of research point to the possibility of a partially overlapping dopaminergic foundation of the trait of agentic extraversion and individual differences in working memory functioning. This study investigates interactive effects of agentic extraversion and dopamine on spectral EEG measures of working memory. Using EEG activity in the alpha 1 band (8-10.25Hz) as a dependent variable, we tested in a randomized double-blind design the effects of the D2-dopamine antagonist sulpiride during the performance of four load-graded n-back working memory tasks in participants high versus low in agentic extraversion. We expected extraversion-related differences in the load-responsivity pattern to be reversed by sulpiride, and the alpha 1 anterior-posterior difference actually depicted this reversal effect. However, in contrast to our expectations this effect was largely due to parietal instead of frontal sites.