Identification of the neural correlates of cyclothymic temperament using a working memory task in fMRI

BackgroundRecently, we reported a significantly negative association of cyclothymic temperament scores with activations of the left lingual gyrus during esthetic judgments of paintings, suggesting that cyclothymic temperament may be associated with the left lingual gyrus. In view of potential associations of cyclothymic temperament, bipolar disorder and dementia, this study examined the relationship of temperament to lingual gyrus activity using a working memory task as a new context.MethodsN-back tasks (0-, 1-, 2- and 3-back tasks) were performed on 34 healthy subjects using functional MRI. Multiple regression analyses were applied to measure the association between cyclothymic temperament scores and each of 4 beta images corresponding to 0-, 1-, 2- and 3-back tasks with gender, age and the other temperament scores (depressive, hyperthymic, irritable and anxious) as covariates.ResultsThe whole brain analysis corrected for multiple comparisons revealed a significant activation of the left lingual gyrus associated with cyclothymic temperament scores in a new context-working memory for both 2- and 3-back tasks.LimitationsThe number of subjects was relatively small. The subjects were almost medical staff or students and the results should be interpreted with caution.ConclusionsThe present findings reconfirm that cyclothymic temperament may be associated with the left lingual gyrus.