Experimental procedure of neurofeedback training (NFT). (A) An NFT contained three phases, that is, pre‐test, training, and post‐test. The training phase contained 12 sessions. Each session contained a 2‐min baseline followed by six blocks of 6‐min training. (B) During the pre‐test and post‐test phases, two working memory tasks (BDST and OST), an episodic memory task (WPT) and four questionnaires (MMSE, BDI, BAI, and PSQI) were performed. BAI, Beck anxiety inventory; BDI, Beck depression inventory; BDST, backward digit span task; MMSE, mini‐mental status examination; OST, operation span task; PSQI, Pittsburgh sleep quality index; WPT, word pair task.