Modulation of Inferotemporal Cortex Activation during Verbal Working Memory Maintenance

Regions of the left inferotemporal cortex are involved in visual word recognition and semantics. We utilized functional magnetic resonance imaging to localize an inferotemporal language area and to demonstrate that this area is involved in the active maintenance of visually presented words in working memory. Maintenance activity in this inferotemporal area showed an effect of memory load for words, but not pseudowords. In the absence of visual input, the selective modulation of this language-related inferotemporal area for the maintenance of words is accompanied by an increased functional connectivity with left prefrontal cortex. These results demonstrate an involvement of inferotemporal cortex in verbal working memory and provide neurophysiological support for the notion that nonphonological language representations can be recruited in the service of verbal working memory. More generally, they suggest that verbal working memory should be conceptualized as the frontally guided, sustained activation of pre-existing cortical language representations.