About the Authors

Li Zhaoping

To whom correspondence should be addressed. E-mail: z.li@ucl.ac.uk

Affiliation Department of Psychology, University College London, London, United Kingdom

Keith A May

Affiliation Department of Psychology, University College London, London, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

LZ conceived and designed the experiments. Both KAM and LZ performed the experiments and analyzed the data, with KAM focusing on the main body of the experiments and data analysis, and LZ on the pilot experiments and on the later parts of the experiments and data analysis. While LZ led the manuscript writing, KAM contributed significantly in the editing and revision process.