T. P. Beauchaine recently proposed a model of autonomic nervous system functioning that predicts divergent patterns of psychophysiological responding across disorders of disinhibition. This model was tested by comparing groups of male adolescents with attention-deficit/hyperactivity disorder (ADHD) and attention-deficit/hyperactivity disorder plus conduct disorder (CD/ADHD) with controls while performing a repetitive motor task in which rewards were administered and removed across trials. Participants then watched a videotaped peer conflict. Electrodermal responding (EDR), cardiac pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA) were monitored. Compared with controls, the ADHD and CD/ADHD participants exhibited reduced EDR. The CD/ADHD group was differentiated from the ADHD and control groups on PEP and from the control group on RSA. Findings are discussed in terms of the motivational and regulational systems indexed. Implications for understanding rates of comorbidity between CD and ADHD are considered.

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Two studies examined the effects of breast-feeding on maternal stress and mood. In Experiment 1, perceived stress in the past month was compared between 28 breast-feeding and 27 bottle-feeding mothers. Breast-feeding mothers reported less perceived stress, after controlling for demographic confounds. In Experiment 2, mood ratings were assessed in the same 24 mothers both before and then after 1 breast-feeding and 1 bottle-feeding session. Breast-feeding was associated with a decrease in negative mood, and bottle-feeding was associated with a decrease in positive mood from pre- to postfeeding. Results indicated that breast-feeding buffers negative mood. These effects appeared to be attributable to the effects of breast-feeding itself and not solely to individual-differences factors.

When people are presented with backward-masked images of fear-relevant stimuli and only some of these images are paired consistently with electric shocks, they can predict the occurrence of shocks even though they do not consciously know which images they have seen. We postulated that they may use the perception of visceral cues from the conditional fear response to facilitate the prediction of shocks. In this study, ability to detect heartbeats was used to index sensitivity to visceral cues. The results showed that subjects who could detect their heartbeats performed better than chance in predicting whether or not they would receive a shock during the conditioning task. The findings support the notion that hunches, or "gut feelings," are based in part on the perception of visceral cues.