Conditioned nausea after cancer chemotherapy and autonomic nervous system conditionability

There are marked individual differences in conditioned nausea after cancer chemotherapy. To examine if part of this variation is associated with individual differences in autonomic nervous system conditionability, the present study addressed whether patients with conditioned nausea acquired conditioned heart rate and electrodermal responses at a different rate than patients without conditioned nausea. Of 28 relapse-free patients who had completed cisplatinum treatment for testicular cancer between 1981 and 1986, 10 reported persistent conditioned nausea, 8 extinguished conditioned nausea and 10 no conditioned nausea. These three groups were subjected to a differential conditioning paradigm with 8 sec pictorial stimuli (circles and triangles) serving as conditioned stimuli for an unconditioned electric shock while heart rate and electrodermal activity was monitored. There were 4 habituation, 8 acquisition and 8 extinction trials with each of the two cues. Analyses of variance using nausea status as the independent variable and physiological responses as the dependent lended some support to the notion that conditioned heart rate deceleration developed in response to the reinforced compared to the nonreinforced cue during acquisition in the two groups with persistent or extinguished conditioned nausea but not in the group with no conditioned nausea. In addition, patients that displayed good, as compared to poor heart rate conditionability during acquisition, were more likely to have persistent conditioned nausea, whereas those who showed poor heart rate conditioning mostly were those without conditioned nausea. Electrodermal variables revealed no systematic differences between groups. This tentatively supports that individual differences in parasympathetic but not sympathetic nervous system conditionability may be associated with individual differences in conditioned nausea resulting from cancer chemotherapy.     

Inverse association between dopaminergic neurotransmission and Iowa Gambling Task performance in pathological gamblers and healthy controls

Linnet, J., Møller, A., Peterson, E., Gjedde, A. & Doudet, D. (2011). Inverse association between dopaminergic neurotransmission and Iowa Gambling Task performance in pathological gamblers and healthy controls. Scandinavian Journal of Psychology 52, 28–34. The dopamine system is believed to affect gambling behavior in pathological gambling. Particularly, dopamine release in the ventral striatum appears to affect decision‐making in the disorder. This study investigated dopamine release in the ventral striatum in relation to gambling performance on the Iowa Gambling Task (IGT) in 16 Pathological Gamblers (PG) and 14 Healthy Controls (HC). We used Positron Emission Tomography (PET) to measure the binding potential of [¹¹C] raclopride to dopamine D2/3 receptors during a baseline and gambling condition. We hypothesized that decreased raclopride binding potentials in the ventral striatum during gambling (indicating dopamine release) would be associated with higher IGT performance in Healthy Controls, but lower IGT performance in Pathological Gamblers. The results showed that Pathological Gamblers with dopamine release in the ventral striatum had significantly lower IGT performance than Healthy Controls. Furthermore, dopamine release was associated with significantly higher IGT performance in Healthy Controls and significantly lower IGT performance in Pathological Gamblers. The results suggest that dopamine release is involved both in adaptive and maladaptive decision‐making. These findings may contribute to a better understanding of dopaminergic dysfunctions in pathological gambling and substance related addictions.     

Combined Effects of Masculine Gender‐Role Stress and Sexual Prejudice on Anger and Aggression Toward Gay Men

This study was designed to examine the extent to which masculine gender‐role stress, sexual prejudice, and antigay anger collectively facilitate antigay aggression. Participants were 135 heterosexual men who completed a structured interview assessing masculine gender‐role stress, sexual prejudice, anger in response to a vignette depicting a non‐erotic male–male intimate relationship (i.e., partners holding hands, kissing), and past perpetration of antigay aggression. The results indicate that the association between masculine gender‐role stress and antigay aggression is partially mediated by antigay anger among sexually prejudiced men. These findings contribute to theoretical understanding of antigay aggression. Implications for future research and intervention are discussed.