Autism spectrum disorders (ASDs) and social anxiety disorder (SAD) are both characterized by social dysfunction, but no study to date has compared neural responses to social rewards in ASDs and SAD. Neural responses during social and non-social reward anticipation and outcomes were examined in individuals with ASD (n = 16), SAD (n = 15) and a control group (n = 19) via functional magnetic resonance imaging. Analyses modeling all three groups revealed increased nucleus accumbens (NAc) activation in SAD relative to ASD during monetary reward anticipation, whereas both the SAD and ASD group demonstrated decreased bilateral NAc activation relative to the control group during social reward anticipation. During reward outcomes, the SAD group did not differ significantly from the other two groups in ventromedial prefrontal cortex activation to either reward type. Analyses comparing only the ASD and SAD groups revealed greater bilateral amygdala activation to social rewards in SAD relative to ASD during both anticipation and outcome phases, and the magnitude of left amygdala hyperactivation in the SAD group during social reward anticipation was significantly correlated with the severity of trait anxiety symptoms. Results suggest reward network dysfunction to both monetary and social rewards in SAD and ASD during reward anticipation and outcomes, but that NAc hypoactivation during monetary reward anticipation differentiates ASD from SAD.

The majority of people who engage in nonsuicidal self-injury (e.g., cutting) report that affect regulation is their primary motivation for these painful behaviors. Unfortunately, little is known about the mechanisms that regulate affect during nonsuicidal self-injury. In the present study, we examined the role of one potential mechanism known as pain offset relief. In 42 participants (21 self-cutters, 21 controls), we measured psychophysiological indices of positive affect (startle postauricular reactivity) and negative affect (startle eyeblink reactivity) after painful electric shocks. Results provided evidence that pain offset relief is a natural and unique mechanism of affect regulation that generates simultaneous—but independent—positive and negative reinforcement. However, associations between nonsuicidal self-injury frequency and pain offset relief variables were weak and nonsignificant. Contrary to contemporary theories, this suggests that the strong association between prior and future self-injury may not be driven by opponent processes that generate stronger relief (and, thus, stronger reinforcement of self-injury) across episodes.

Although pain itself induces negative affect, the removal (or offset) of pain induces a powerful state of relief. Despite being implicated in a wide range of psychological and behavioral phenomena, relief remains a poorly understood emotion. In particular, some theorists associate relief with increased positive affect, whereas others associate relief with diminished negative affect. In the present study, we examined the affective nature of relief in a pain-offset paradigm with psychophysiological measures that were specific to negative valence (startle eyeblink reactivity) and positive valence (startle postauricular reactivity). Results revealed that pain offset simultaneously stimulates positive affect and diminishes negative affect for at least several seconds. Results also indicated that pain intensity differentially affects the positive and negative valence aspects of relief. These findings clarify the affective nature of relief and provide insight into why people engage in both normal and abnormal behaviors associated with relief.