Mechanisms for maintaining information in working memory.

The review by Slotnick is valuable for raising the important question of how much the hippocampal activity induced by novel stimuli is due to mechanisms for encoding into long-term memory, and how much is due to working memory. Slotnick's paper implicitly defines working memory as being equivalent to sustained activation during the late delay period. In this commentary, we suggest that cognitive neuroscientists should consider a broader range of cellular and synaptic mechanisms for maintaining information in working memory.