The researchers used a number of regressive tasks to train a human brain function - working memory  All subjects were divided into four groups on average, namely, no training group, 8-day, 12-day and 17-day training group  All subjects (including no training group) received intelligence tests before and after training
With the increase of training time, the rate of intelligence improvement is slowing down
 The study found that the intelligence level of the training group was significantly improved compared with that of the no training group, It is concluded that working memory training can improve intelligence