Sang Won Lee1, Hyunsil Cha2, Younjae Chung3,4, Eunji Kim2, Huijin Song5, Yongmin Chang6,7, Seung Jae Lee3,4. 1. Department of Psychiatry, Kyungpook National University Chilgok Hospital, Daegu, Korea. 2. Department of Medical & Biological Engineering, School of Medicine, Kyungpook National University, Daegu, Korea. 3. Department of Psychiatry, Kyungpook National University Hospital, Daegu, Korea. 4. Department of Psychiatry, School of Medicine, Kyungpook National University, Daegu, Korea. 5. Institute of Biomedical Engineering Research, Kyungpook National University, Daegu, Korea. 6. Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu, Korea. 7. Department of Radiology, Kyungpook National University Hospital, Daegu, Korea.
Abstract
BACKGROUND: Thought-action fusion (TAF) represents an individual's belief that a thought is like action. Inflated TAF has been considered a central mechanism for developing obsessive thoughts. However, the neural mechanisms underlying TAF are yet unknown. METHODS: We recruited 32 healthy men to participate in a functional magnetic resonance imaging (fMRI) study. Whereas inside the 3T MRI scanner, participants were asked to read negative statements describing the expectation of bad events associated with close persons (CPs condition) or neutral persons (NPs condition). They also completed the assessment of TAF and obsessive-compulsive (OC) symptoms. RESULTS: Both CP and NP conditions commonly activated the lingual gyrus, caudate nucleus, precuneus, and several areas of the frontal cortex. Importantly, many of these regions were positively correlated with measures of OC symptoms, especially for the CP condition. The CP condition showed higher activation in the insula and temporal gyrus than the NP condition. In contrast, the NP condition evoked higher activation in regions associated with mentalizing, such as the medial prefrontal cortex and dorsal anterior cingulate cortex than the CP condition. CONCLUSIONS: We introduced and validated a TAF-induction paradigm suitable for fMRI studies and characterized the neural circuits engaged during this paradigm. Further studies using this task may help us to better understand how dysfunctions in TAF neural processing may contribute to psychiatric conditions such as obsessive-compulsive disorder.
BACKGROUND: Thought-action fusion (TAF) represents an individual's belief that a thought is like action. Inflated TAF has been considered a central mechanism for developing obsessive thoughts. However, the neural mechanisms underlying TAF are yet unknown. METHODS: We recruited 32 healthy men to participate in a functional magnetic resonance imaging (fMRI) study. Whereas inside the 3T MRI scanner, participants were asked to read negative statements describing the expectation of bad events associated with close persons (CPs condition) or neutral persons (NPs condition). They also completed the assessment of TAF and obsessive-compulsive (OC) symptoms. RESULTS: Both CP and NP conditions commonly activated the lingual gyrus, caudate nucleus, precuneus, and several areas of the frontal cortex. Importantly, many of these regions were positively correlated with measures of OC symptoms, especially for the CP condition. The CP condition showed higher activation in the insula and temporal gyrus than the NP condition. In contrast, the NP condition evoked higher activation in regions associated with mentalizing, such as the medial prefrontal cortex and dorsal anterior cingulate cortex than the CP condition. CONCLUSIONS: We introduced and validated a TAF-induction paradigm suitable for fMRI studies and characterized the neural circuits engaged during this paradigm. Further studies using this task may help us to better understand how dysfunctions in TAF neural processing may contribute to psychiatric conditions such as obsessive-compulsive disorder.