Alzheimer's disease (AD) is the most common form of neurodegenerative disorders leading to dementia. Currently, there has been no effective pharmacologic therapy for this disease. Electroencephalogram-based neurofeedback is considered as a potentially treatment strategy. In this project, the investigators aim to investigate the effectiveness of neurofeedback therapy on cognition for individuals with subjective cognitive decline (SCD). Participants will receive electroencephalogram-based neurofeedback therapy once a day for successive five days. Then, the investigators will evaluate the changes of memory function between baseline and post-therapy visits.