To illustrate this point with an extreme example, consider a study subject in a verbal free-recall task. The subject opens their eyes for two words per list and encodes them but closes their eyes for all others. The SME would likely show a dramatic effect in the occipital cortex, which is not wholly wrong; visual processing is a key step in parsing items and context. But the resulting statistical picture could obscure important effects happening elsewhere in the brain unrelated to vision but essential for episodic memory processing. If, for example, visual attention is associated with strong decreases in theta power, but memory is associated with mild increases, the SME in this toy example would guide a researcher to a misleading conclusion about how the brain encodes memories.
