Functional changes of the reward system underlie blunted response to social gaze in cocaine users

Abstract

Social interaction deficits in drug users likely impede treatment, increase the burden of the affected families, and consequently contribute to the high costs for society associated with addiction. Despite its significance, the neural basis of altered social interaction in drug users is currently unknown. Therefore, we investigated basal social gaze behavior in cocaine users by applying behavioral, psychophysiological, and functional brain-imaging methods. In study I, 80 regular cocaine users and 63 healthy controls completed an interactive paradigm in which the participants' gaze was recorded by an eye-tracking device that controlled the gaze of an anthropomorphic virtual character. Valence ratings of different eye-contact conditions revealed that cocaine users show diminished emotional engagement in social interaction, which was also supported by reduced pupil responses. Study II investigated the neural underpinnings of changes in social reward processing observed in study I. Sixteen cocaine users and 16 controls completed a similar interaction paradigm as used in study I while undergoing functional magnetic resonance imaging. In response to social interaction, cocaine users displayed decreased activation of the medial orbitofrontal cortex, a key region of reward processing. Moreover, blunted activation of the medial orbitofrontal cortex was significantly correlated with a decreased social network size, reflecting problems in real-life social behavior because of reduced social reward. In conclusion, basic social interaction deficits in cocaine users as observed here may arise from altered social reward processing. Consequently, these results point to the importance of reinstatement of social reward in the treatment of stimulant addiction. joint attention | reinforcement | social cognition | dopamine | social functioning

The Fabric of Meaning and Subjective Effects in LSD-Induced States Depend on Serotonin 2A Receptor Activation

“…Therefore, the 5-HT2AR may also be involved in dysfunctional personal relevance attribution observed in psychiatric disorders such as schizophrenia and addiction [2,3,30,31]. Overattribution of personal relevance and potential consequences thereof should also be taken into account when LSD is considered to be used therapeutically.…”

Impaired self-awareness in human addiction: deficient attribution of personal relevance

“…In an interesting recent study, participants were instructed to follow or not follow the gaze of an unfamiliar virtual character. Although pupil dilation, a proxy of task engagement, was higher during mutual gazing in all participants, this effect was attenuated in the cocaine-addicted individuals (40). In a subsample of these participants who completed functional magnetic resonance imaging (fMRI) during this paradigm, controls had more activity in the rACC/vmPFC than did cocaine-addicted individuals during the mutual gaze condition (Figure 3D) (40).…”

“…Although pupil dilation, a proxy of task engagement, was higher during mutual gazing in all participants, this effect was attenuated in the cocaine-addicted individuals (40). In a subsample of these participants who completed functional magnetic resonance imaging (fMRI) during this paradigm, controls had more activity in the rACC/vmPFC than did cocaine-addicted individuals during the mutual gaze condition (Figure 3D) (40). This study suggests that addicted individuals perceive social interactions as being less engaging, novel, rewarding, or personally relevant, with potential far-reaching consequences for real-life interpersonal relationships.…”

“…(B) Methamphetamine-addicted individuals had lower bilateral rACC activity during a risky decision-making task across all decisions; and (C) the lower the activity in the right rACC, the more times a risky choice was selected following a loss [adapted from (37), with permission from John Wiley and Sons]. (D) Compared with healthy controls, cocaine-addicted individuals had less rACC/vmPFC activity during a social interaction task [adapted from (40), with permission from the National Academy of Sciences].…”

Effects of levodopa-carbidopa-entacapone and smoked cocaine on facial affect recognition in cocaine smokers

“…Thus, cocaine users show indicators of social marginalization and a range of problems in daily social function. While their specific causes remain unclear, these social and interpersonal issues may have important implications for engagement and success in treatment (Preller et al, 2014a, Verdejo-Garcia, 2014). …”