Nine "false belief command trials" and 18 "reality command trials" were presented.
False belief command trials and reality command trials were presented in a pseudorandom order, avoiding consecutive false belief command trials in order to reduce the likelihood of participants inferring the purpose of the experiment.
For the task of applying understanding of false beliefs, a significant main effect for group was found on belief command trials [ F 2,138)=22.204, P<0.001], but not for reality command trials [ F 2,138)=1.230, P=0.299].
A total of 9 false belief probes about the character's false beliefs were presented in the trials corresponding to the false belief command trials in the task of applying others' false beliefs.
A total of 18 reality probes about the reality information were presented in the trials corresponding to the reality command trials in the task of applying others' false beliefs.
To respond correctly in reality command trials, participants only needed to choose the target box according to their own knowledge of the contents of the seven non-secretive boxes.
Post-hoc comparisons (Bonferroni corrected) showed that both the remitted schizophrenia group (P<0.001) and the non-remitted schizophrenia group (P<0.001) performed worse than healthy controls on false belief command trials.
In the reality command trials, the statement made to ZhangHong referred to one of the other seven boxes (e.g., "Please choose which box contains the apple". Figure 1 bottom-right), in which her belief corresponds with reality.
In the false belief command trials, the command statement referred to the fruit that is named on the critical secretive box but which is actually inside the other secretive box (e.g., "Please choose which box contains the banana". Figure 1. top-right).
There are several explanations: the variability in the preparation of movement, the variability in the corticospinal tract command from trial-to-trial, the variability in the muscle contraction from trial-to-trial and the electro-mechanical delay in muscle contraction (see Jenkins, Palmer and Cramer (2013) and Howatson et al. (2009)).
