Masked Smoking-Related Images Modulate Brain Activity in Smokers

• Authors: Xiaochu Zhang, University of Science and Technology of China; Xiangchuan Chen, Emory University; Yongqiang Yu, Anhui Medical University; Delin Sun, University of Science and Technology of China; Ning Ma, University of Science and Technology of China; Sheng He, University of Minnesota; Xiaoping Hu, Emory University; Daren Zhang, University of Science and Technology of China
• Journal Title: Human Brain Mapping
• Volume: Volume 30, Number 3
• Publisher: Wiley | 2009-03-01, Pages 896-907
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1002/hbm.20552
• Subjects: Health Sciences, Radiology; Biology, Neuroscience; Engineering, Biomedical
• Keywords: Science & Technology; Life Sciences & Biomedicine; Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging; Neurosciences & Neurology; unawareness; smoking-related cue; functional magnetic resonance imaging (fMRI); amygdala; addiction; Event related MRI; Functional connectivity; Nicotine dependence; Drug addiction; Human amygala; Fagerstrom test; Cue reactivity; Activation; Responses; Fear

Abstract

The questions of whether and how indiscriminate drug-related stimuli could influence drug- users are important to our understanding of addictive behavior, but the answers are still inconclusive. In the present preliminary functional magnetic resonance imaging study using a backward masking paradigm, the effect of indiscriminate smoking-related stimuli on 10 smokers and 10 nonsmokers was examined. The BOLD response showed a significant reduction (P = 0.001) in the right amygdala of smokers when they viewed but did not perceive masked smoking-related stimuli, while no significant differences were found in the nonsmoker group. More voxels in anterior cingulate cortex were negatively correlated with the amygdala during the masked smoking-related picture condition in smokers but not in nonsmokers, whereas more positively correlated voxels were observed during the masked neutral condition. The BOLD response in drug-users indicates the amygdala responds to drug-related stimuli that are below the perceptual threshold. The functional connectivity data suggest a functional interaction between the amygdala and the anterior cingulate cortex when drug users view 33ms back- masked drug-related stimuli. This observation suggests that the amygdala plays an important role in the indiscriminate drug-related cue process.