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Additional Information

Competing Interests

The authors declare there are no competing interests.

Author Contributions

Christopher Lai conceived and designed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.

Chun-Fai Ellis Li performed the experiments, prepared figures and/or tables.

Human Ethics

The following information was supplied relating to ethical approvals (i.e., approving body and any reference numbers):

This study was approved by the panel for summer research studentship, Faculty of Health and Social Science, The Hong Kong Polytechnic University.

Data Deposition

The following information was supplied regarding the deposition of related data:

(link 1) Image capture for operator B performing Right click:

(link 2) Raw data: results from all operators:


The study was supported and funded by Faculty of Health and Social Sciences, the Hong Kong Polytechnic University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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