Amphetamine as a social drug: effects of d-amphetamine on social processing and behavior
- 836 Downloads
Drug users often report using drugs to enhance social situations, and empirical studies support the idea that drugs increase both social behavior and the value of social interactions. One way that drugs may affect social behavior is by altering social processing, for example by decreasing perceptions of negative emotion in others.
We examined effects of d-amphetamine on processing of emotional facial expressions and on the social behavior of talking. We predicted amphetamine would enhance attention, identification, and responsivity to positive expressions, and that this in turn would predict increased talkativeness.
Over three sessions, 36 healthy normal adults received placebo, 10, and 20 mg d-amphetamine under counterbalanced double-blind conditions. At each session, we measured processing of happy, fearful, sad, and angry expressions using an attentional visual probe task, a dynamic emotion identification task, and measures of facial muscle activity. We also measured talking.
Amphetamine decreased the threshold for identifying all emotions, increased negative facial responses to sad expressions, and increased talkativeness. Contrary to our hypotheses, amphetamine did not alter attention to, identification of, or facial responses to positive emotions specifically. Interestingly, the drug decreased the threshold to identify all emotions, and this effect was uniquely related to increased talkativeness, even after controlling for overall sensitivity to amphetamine.
The results suggest that amphetamine may encourage sociability by increasing sensitivity to subtle emotional expressions. These findings suggest novel social mechanisms that may contribute to the rewarding effects of amphetamine.
KeywordsAmphetamine Emotional faces Attentional bias Social interaction Psychophysiology
The authors thank Dr. John Cacioppo and his staff at the University of Chicago Center for Cognitive and Social Neuroscience for their technical assistance; Adam D. I. Kramer for statistical consulting; and Cassandra Esposito, Celina Joos, and Megan Leino for their work on this study. The National Institute on Drug Abuse supported this work through grant R01 DA02812 to Dr. Harriet de Wit. Dr. Wardle is supported by a National Institute on Drug Abuse Training grant, T32 DA007255. The authors declare no potential financial or other conflicts of interest.
- Bates DM, Meachler M, Bolker B (2011) lme4: linear mixed-effects model using S4 classesGoogle Scholar
- First MB, Spitzer RL, Gibbon M, Williams JB (1996) Strutured clinical interview for DSM-IV axis I disorders. Biometrics Research Department, New YorkGoogle Scholar
- Hysek C, Domes G, Liechti M (2012) MDMA enhances “mind reading” of positive emotions and impairs “mind reading” of negative emotions. Psychopharmacology (Berl): 1–10. doi: 10.1007/s00213-012-2645-9
- Kornreich C, Foisy M-L, Philippot P, Dan B, Tecco J, Noël X, Hess U, Pelc I, Verbanck P (2003) Impaired emotional facial expression recognition in alcoholics, opiate dependence subjects, methadone maintained subjects and mixed alcohol-opiate antecedents subjects compared with normal controls. Psychiatry Res 119:251–260PubMedCrossRefGoogle Scholar
- Lang PJ, Bradley MM, Cuthbert BN (1999) International affective picture system (IAPS): technical manual and affective ratings. NIMH Center for the study of emotion and attention, University of Florida, GainesvilleGoogle Scholar
- Pennebaker JW, Booth RJ, Francis ME (2007) Linguistic inquiry and word count: LIWC 2007. LIWC, AustinGoogle Scholar
- R Development Core Team (2011) R: A language and environment for statistical computing. R Foundation for Statistical Computing, ViennaGoogle Scholar
- Raudenbush SW, Bryk AS (2002) Hierarchical linear models: Applications and data analysis methods. Sage, Newbury ParkGoogle Scholar
- Spielberger CD, Gorsuch RL, Lushene R, Vagg PR, Jacob GA (1983) Manual for the state-trait anxiety inventory. Consulting Psychologists, Palo AltoGoogle Scholar
- Walter NT, Mutic S, Markett S, Montag C, Klein AM, Reuter M (2011) The influence of alcohol intake and alcohol expectations on the recognition of emotions. Alcohol Alcohol. doi: 10.1093/alcalc/agr082