Response to Letter to the Editor: Effects of Cognitive-Physical Dual-Task Training on Executive Function and Activity in the Prefrontal Cortex of Older Adults With Mild Cognitive Impairment.

Thajus Asirvatham raises important points. The first concern is about an outcome measurement used in the study to assess executive function. As he indicated, the Trail Making Test Part B (TMT-B) is one of conventional neuropsychological assessments, focusing on evaluating executive function itself rather than functionally assessing it. Nevertheless, the reason why the TMT-B was used is that one of the purposes of the study was to measure cerebral blood flow during executive functioning. The Korean version of the Executive Function Performance Test (EFPT-K) is a top-down performance assessment [3]. Since the EFPT-K requires participants to complete some tasks, measurements of cerebral blood flow using a functional near-infrared spectroscopy during the tasks might be inappropriate due to noise [4].