PURPOSE: The aim of this study was to investigate the influence of the subject's emotional state on the BOLD signal during simple finger tapping. MATERIAL AND METHODS: Twenty-nine healthy subjects participated in three functional magnetic resonance imaging (fMRI) sessions each. The sessions differed regarding emotional states, which were induced by standardized pleasant (positive condition, POS), unpleasant (negative condition, NEG), or neutral (neutral condition, NEU) pictures taken from the International Affective Picture System (IAPS) while the subjects performed a finger-tapping task (right index-to-thumb opposition). After each session, the subjects had to rate their actual mood and the pleasantness of the presented pictures. Furthermore, their state anxiety was assessed. Behavioral data were evaluated with SPSS. Functional imaging data were processed using statistical parametric mapping (SPM2) and were analyzed for main effects of emotional stimulation using an analysis of variance (ANOVA). The local maximum of interest was analyzed by a signal change analysis. RESULTS: Compared to the neutral emotional state, the positive and the negative emotional states caused a reduction of signal intensity changes within the primary sensorimotor hand area during simple finger tapping. The behavioral data indicated that the unpleasant pictures had a stronger effect on the emotional state than the pleasant images. According to these data the decrease in signal intensity change was more pronounced (significant; p < 0.001) in the negative condition than in the positive condition. CONCLUSION: This study showed that the emotional state of a test person is indeed influencing fMRI results and that well-balanced subjects in a neutral mood achieve the best fMRI results.
PURPOSE: The aim of this study was to investigate the influence of the subject's emotional state on the BOLD signal during simple finger tapping. MATERIAL AND METHODS: Twenty-nine healthy subjects participated in three functional magnetic resonance imaging (fMRI) sessions each. The sessions differed regarding emotional states, which were induced by standardized pleasant (positive condition, POS), unpleasant (negative condition, NEG), or neutral (neutral condition, NEU) pictures taken from the International Affective Picture System (IAPS) while the subjects performed a finger-tapping task (right index-to-thumb opposition). After each session, the subjects had to rate their actual mood and the pleasantness of the presented pictures. Furthermore, their state anxiety was assessed. Behavioral data were evaluated with SPSS. Functional imaging data were processed using statistical parametric mapping (SPM2) and were analyzed for main effects of emotional stimulation using an analysis of variance (ANOVA). The local maximum of interest was analyzed by a signal change analysis. RESULTS: Compared to the neutral emotional state, the positive and the negative emotional states caused a reduction of signal intensity changes within the primary sensorimotor hand area during simple finger tapping. The behavioral data indicated that the unpleasant pictures had a stronger effect on the emotional state than the pleasant images. According to these data the decrease in signal intensity change was more pronounced (significant; p < 0.001) in the negative condition than in the positive condition. CONCLUSION: This study showed that the emotional state of a test person is indeed influencing fMRI results and that well-balanced subjects in a neutral mood achieve the best fMRI results.