Funding for this research was provided by:
Major Research Plan (31571150)
National Natural Science Foundation of China (31730038)
Ministry of Education of the People's Republic of China (B07008)
Received: 7 September 2019
Accepted: 29 January 2020
First Online: 4 February 2020
Ethics approval and consent to participate
: This experiment was approved by the Institutional Review Board (IRB) of the State Key Laboratory of Cognitive Neuroscience and Learning at Beijing Normal University. A signed consent form was obtained from each participant after a full explanation of the study procedure.
: Not applicable.
: The authors declare that they have no competing interests.