Rationale
Motivational drive and its underlying affect-related states are the core mechanisms that precede the seeking and taking of drugs in substance dependence.
Objective
The present study aimed to investigate the motivational relevance of cocaine cues and whether or not an appetitive emotional system is involved employing event-related potential (ERP) measurements.
Methods
Cocaine-addicted subjects and healthy controls were exposed to neutral and cocaine-related pictures whilst ERPs were recorded simultaneously over frontal, parietal and midline sites.
Results
Patients exhibited ERP amplitude discrepancies between neutral and cocaine-related pictures for N300, late slow positive wave (LSPW) and sustained slow positive wave (SSPW), whilst this effect was absent in control subjects. Differences in neutral and cocaine cue-evoked ERP waves were also found at left frontal sites for LSPW and SSPW in the patient group only. No group-specific cue-evoked ERP amplitudes were observed at parietal and midline sites.
Conclusion
The findings confirm the assumption that cocaine cues induce motivational relevance in cocaine-dependent individuals. It is possible that exposure to cocaine cues triggers an appetitive emotional system since left frontal sites are assumed to be involved in processing positive emotional-laden stimuli. The present study provides evidence that the sensitivity of ERP correlates for cocaine cues may be an indicator of motivational and emotional processes in drug-dependent individuals.