fNIRS will be conducted during the whole procedure of the treatment in the 1st treatment sessions and the last treatment session (6th treatment). This is a safe and non-invasive imaging to assess the brain activation. Brain activation hemodynamic signals (e.g., concentration level of Oxygenated Hemoglobin (O2Hb) and Deoxygenated Hemoglobin (HHb)) over the left dorsolateral prefrontal cortex (DLPFC) will be measured by a customized portal fNIRS device.