In this paper, we report an attempt to utilize Electroencephalography (EEG) signals for judging the correctness of the performed perception-assist in an upper-limb power-assist exoskeleton. Although Electromyography (EMG) signals can be used for judgments, lack of change in EMG signals and the complexity of the upper-limb motions sometimes make it difficult to evaluate the perception-assist using EMG signals. In this study, we investigate whether EEG signals can alone be used instead of EMG signals to judge the correctness of the perception-assist performed by the exoskeleton. Experiments are carried out with three healthy subjects and the results are presented in this paper. Moreover, we show the potentials and advantages of using EEG signals recorded from brain of the users to judge correctness of the perception-assist in upper-limb power-assist exoskeletons.