Dissociation of Striosome and Matrix Activation in the Human Striatum During the Cue and Execution Phases of Working Memory

Striatal medium spiny neurons are organized into two interdigitated compartments, the striosome and matrix, which are embryologically, pharmacologically, and anatomically distinct. Compartment-specific functions have been demonstrated in animals, but their roles in human cognition are unexplored.We found that in humans, striosome-like voxels preferentially activated during memory cues, while matrix-like voxels preferentially activated during recall and memory maintenance. In both compartments, activation scaled with task difficulty.Activation in striosome-like voxels scaled more strongly with task accuracy and difficulty, suggesting a striosome-selective role in vigilance and/or motivation.