ORIGINAL RESEARCH Working memory capacity and the functional connectome - insights from resting-state fMRI and voxelwise centrality mapping Sebastian Markett 1,2 & Martin Reuter 1,2 & Behrend Heeren 3 & Bernd Lachmann 4 & Bernd Weber 2,4,5 & Christian Montag 6,7 # Springer Science+Business Media New York 2017 Abstract The functional connectome represents a compre- hensive network map of functional connectivity throughout the human brain. To date, the relationship between the orga- nization of functional connectivity and cognitive performance measures is still poorly understood. In the present study we use resting-state functional magnetic resonance imaging (fMRI) data to explore the link between the functional connectome and working memory capacity in an individual differences design. Working memory capacity, which refers to the maximum amount of context information that an individ- ual can retain in the absence of external stimulation, was assessed outside the MRI scanner and estimated based on behavioral data from a change detection task. Resting-state time series were analyzed by means of voxelwise degree and eigenvector centrality mapping, which are data-driven net- work analytic approaches for the characterization of function- al connectivity. We found working memory capacity to be inversely correlated with both centrality in the right intraparietal sulcus. Exploratory analyses revealed that this relationship was putatively driven by an increase in negative connectivity strength of the structure. This resting-state con- nectivity finding fits previous task based activation studies that have shown that this area responds to manipulations of working memory load. Keywords Working memory . Resting-state fMRI . Connectome . Intraparietal sulcus . Working . memory capacity, cognitive ability Introduction The ability to retain and to manipulate information, even in the absence of external stimulation, is a key prerequisite for goal-directed and purposeful interaction with the environ- ment. The mental faculty underlying this ability has been labeled working memory (Baddeley and Hitch 1974; Goldman-Rakic 1995) and is one of the most central con- cepts in cognitive psychology and the cognitive neurosci- ences, most likely because of its relevance for clinical phe- notypes (Lee and Park 2005), intelligence (Conway et al. 2003) and academic success (Alloway and Alloway 2010). A distributed set of brain regions supports working memory processes with lateral prefrontal cortex (PFC) being the most prominent (Owen et al. 2005). Lateral PFC shows sustained activity during the retention of information in working memory. It is debated however, if lateral PFC stores information itself (Sreenivasan et al. 2014; Riley and Constantinidis 2016). Current systems neuroscience ac- counts content that lateral PFC provides attentional control signals that exert control over extrastriate areas that hold representations of the retained information online (Smith * Sebastian Markett sebastian.markett@uni-bonn-diff.de 1 Department of Psychology, University of Bonn, Kaiser-Karl-Ring 9, 53111 Bonn, Germany 2 Center for Economics and Neuroscience, University of Bonn, Bonn, Germany 3 Institute for Numerical Simulation, University of Bonn, Bonn, Germany 4 Department of Epileptology, University of Bonn, Bonn, Germany 5 Department of NeuroCognition, Life & Brain Center, University of Bonn, Bonn, Germany 6 Institute of Psychology and Education, Ulm University, Ulm, Germany 7 Key Laboratory for NeuroInformation, University of Electronic Science and Technology of China, Chengdu, China Brain Imaging and Behavior DOI 10.1007/s11682-017-9688-9