Internal attention study

This experiment has 20 subjects. Subjects asked to mentally concentrate on
a target (see published article for more information) for periods of about
15 seconds.

There are 4 verbal instructions given to subject by an automated computer
program connected to a speakerphone:
- The instruction is to wait until the experiment starts
- The instruction is to relax
- The instruction is to get ready as the trial is about to start
- The instruction is to mentally concentrate on the target

All the experiment is performed eye's closed. Relax periods last for about
9 seconds, are then followed by a period of 6 seconds where the participants
is asked to "get ready" for the trial, followed by a period of 15 seconds of
concentration. This sequence is repeated 20 times for each participant.

本实验共包含20名受试者。受试者需将精神注意力集中于目标对象（详细信息可参阅已发表论文），单次集中时长约为15秒。
实验通过连接免提扬声器的自动化计算机程序向受试者下达4条口头指令：
- 等待实验启动
- 放松身心
- 试验即将开始，请做好准备
- 将注意力集中于目标对象

实验全程要求受试者保持闭眼状态。放松阶段时长约9秒，随后进入6秒的准备阶段，提示受试者为试验做好准备，紧接着是15秒的注意力集中阶段。每名受试者需重复该流程20次。