Near Infrared Spectroscopic Study of Brain Activity during Cognitive Conflicts on Facial Expressions

摘要

The Stroop task has been typically used for measuring cognitive functions of inhibition and interference. However, this task has limited applications with young children, because reading ability is required to perform the task. Using a new, non-letter Stroop-like task named the ‘happy-sad task,’ in which participants are instructed to say ‘happy’ for a sad face and ‘sad’ for a happy face, we can assess differences in inhibition in participants from early childhood to adulthood. We investigated whether differences between the happy-sad task and the letter Stroop task could be observed in brain activation of healthy participants (N = 30), by using near-infrared spectroscopy (NIRS) and skin conductance responses (SCR). We focused on the right and left anterior prefrontal cortex and frontal pole, which are known as centers for response inhibition and processing of emotions. We used region-of-interest analysis that approximately covered these regions and compared brain activation patterns between the two tasks. Results indicated that there was prefrontal activation during both tasks. Particularly, the incongruent condition of the happy-sad task resulted in greater activation than the letter Stroop task. In addition, SCR amplitude for the happy-sad task was greater than that for the letter Stroop task. These findings suggest that brain activity in the happy-sad task is associated with suppression of emotions and inhibition of behavior.