Proneness to hypomania predicts EEG coherence between left motor cortex and left prefrontal cortex.

Previous research has demonstrated that hypomania is associated with approach motivation and activity in the left prefrontal cortex (PFC). Other research has linked left motor cortex excitability to approach motivation, suggesting the existence of connections between the motor cortex and PFC. The present research extends this work using unilateral hand contractions to manipulate contralateral cortical activity, and examining the relationship between motor cortex and PFC inter-electrode EEG coherence and hypomania. Within the right-hand contraction condition, hypomania related to greater connectivity between the left motor cortex and left PFC, relative to connectivity between the left motor cortex and right PFC. No relationships were found within the left-hand condition. The present research provides additional support for the role of the left PFC in bipolar disorder, as well as an important extension of research linking motor cortex excitability to emotion and approach motivation.