Intons-Peterson (1983) found similar results in imaginal scanning experimenters. She concluded that participants in imagery experiments were sensitive to subtle, unintentional cues given by experimenters, including slight differences in intonation or pauses when reading instructions. Intons-Peterson further argued that imagery research, by virtue of the subjective nature of the phenomenon under study, may be especially vulnerable to demand characteristics and experimenter expectations. Although she did not assert that results from all visual imagery experiments are the result of experimenter effects and demand characteristics, she did warn that visual imagery researchers must take special care to minimize these effects.