public static void EndExperiment()
    {
        AudioPlayer.Play(AudioPlayer.AudioName.Final);
        instance.state      = ExperimentState.Relax;
        instance.expEndTime = DateTime.Now;

        float time = (float)(instance.expEndTime.Ticks - instance.expStartTime.Ticks) / (float)TimeSpan.TicksPerSecond;

        //long time = (ExpEndTime.Ticks - ExpStartTime.Ticks) / 1000000;
        Debug.Log("Time Cost: " + time.ToString("F3"));
        //hintText.text = "The End. Total Cost: " + time;
        //instance.hintText.text = "End of Experiment!! Thank U";

        instance.PrintSummary();
        instance.recordManager.Stop();
    }