NeuroImage 60 (2012) 117–129 Contents lists available at SciVerse ScienceDirect NeuroImage journal homepage: www.elsevier.com/locate/ynimg Cognitive: Executive Function The functional connectivity of the human caudate: An application of meta-analytic connectivity modeling with behavioral filtering Jennifer L. Robinson a,b,c,d,⁎, Angela R. Laird c, David C. Glahn e, John Blangero f, Manjit K. Sanghera a, Luiz Pessoa g, P. Mickle Fox c, Angela Uecker c, Gerhard Friehs a, Keith A. Young b,d, Jennifer L. Griffin b,d, William R. Lovallo h, Peter T. Fox c a Neuroscience Institute, Scott & White Healthcare, Texas A&M Health Science Center, College of Medicine, Temple, TX, USA b VISN 17 Center of Excellence for Research on Returning War Veterans, Central Texas Veterans Health Care System, Waco, TX, USA c Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA d Texas A&M Health Science Center, College of Medicine, Department of Psychiatry and Behavioral Science, Temple, TX, USA e Olin Neuropsychiatric Research Center, Institute of Living and Yale University, Department of Psychiatry, New Haven, CT, USA f University of Texas Health Science Center, Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA g Department of Psychology, University of Maryland, College Park, MD, USA h Behavioral Sciences Laboratories, Veterans Affairs Medical Center, Oklahoma City, Oklahoma, USA article info abstract Article history: Meta-analysis based techniques are emerging as powerful, robust tools for developing models of connectivity Received 6 September 2011 in functional neuroimaging. Here, we apply meta-analytic connectivity modeling to the human caudate to 1) Revised 30 November 2011 develop a model of functional connectivity, 2) determine if meta-analytic methods are sufficiently sensitive Accepted 6 December 2011 to detect behavioral domain specificity within region-specific functional connectivity networks, and 3) com- Available online 14 December 2011 pare meta-analytic driven segmentation to structural connectivity parcellation using diffusion tensor imag- fi Keywords: ing. Results demonstrate strong coherence between meta-analytic and data-driven methods. Speci cally, fi Meta-analytic connectivity modeling we found that behavioral ltering resulted in cognition and emotion related structures and networks primar- Functional connectivity ily localized to the head of the caudate nucleus, while perceptual and action specific regions localized to the MACM body of the caudate, consistent with early models of nonhuman primate histological studies and postmortem DTI studies in humans. Diffusion tensor imaging (DTI) revealed support for meta-analytic connectivity mode- Caudate ling's (MACM) utility in identifying both direct and indirect connectivity. Our results provide further valida- tion of meta-analytic connectivity modeling, while also highlighting an additional potential, namely the extraction of behavioral domain specific functional connectivity. Published by Elsevier Inc. Introduction neurological disorders, few studies have examined the functional connectivity of the human caudate (Di Martino et al., 2008; The human dorsal striatum contains the primary input to the basal Postuma and Dagher, 2006), and no study, to our knowledge, has ex- ganglia (Grahn et al., 2008; Haber, 2003). Composed of the caudate amined functional connectivity in this structure using advanced and putamen, it receives axons from all regions of the cortex with meta-analytic techniques. In the present study, we used meta- the exception of the primary visual, auditory, and olfactory cortices analytic connectivity modeling (MACM) (Robinson et al., 2010)to (Grahn et al., 2008). Anatomical, functional, and/or connectivity ab- provide an initial model of functional connectivity utilizing decades normalities of the caudate nuclei have been noted in a wide range worth of neuroimaging data collected across various behavioral do- of disorders including autism (Turner et al., 2006), Huntington's dis- mains. Describing connectivity models in this manner has the poten- ease (Bohanna et al., 2011), Parkinson's disease (PD) (Rowe et al., tial to facilitate discovery of specific pathways that are aberrant in 2008), human immunodeficiency virus (HIV) (Melrose et al., 2008), populations with known dysfunction of the caudate, which may ulti- drug addiction (Ma et al., 2011), depression (Bluhm et al., 2009), mately lead to the identification of novel interventions. and attention deficit hyperactivity disorder (ADHD) (Casey et al., Early models of the basal ganglia assigned to the caudate a prima- 2007). Despite its involvement in a range of psychiatric and ry role of integrating information from the cortical association and sensorimotor areas of the brain before sending it to distinct ventrolat- eral thalamic sub-regions, which would then relay the information al- ⁎ Corresponding author at: Scott & White Memorial Hospital, Neuroscience Institute, 2401 S. 31st Street, Temple, TX 76508. Fax: +1 254 724 6332. most exclusively to the primary motor cortex. These early models E-mail address: [email protected] (J.L. Robinson). have largely been replaced by more complex ones based on evidence 1053-8119/$ – see front matter. Published by Elsevier Inc. doi:10.1016/j.neuroimage.2011.12.010 118 J.L. Robinson et al. / NeuroImage 60 (2012) 117–129 of reciprocating but interconnected circuits that link the cortex, basal Caudate head and body ROIs ganglia, and thalamus (Alexander and Crutcher, 1990; Alexander et Given that cytoarchitectural, histological, and early neuroimaging al., 1986; DeLong et al., 1983). Five primary circuits have been pro- studies suggested a behavioral domain segmentation of the caudate, posed in the nonhuman primate literature: motor, oculomotor, dor- such that the head of the caudate was thought to be involved in solateral prefrontal, lateral orbitofrontal, and anterior cingulate more cognition and emotion related processes, while the body/tail (Alexander et al., 1986). In each of these proposed circuits, the basal was involved primarily with action and perception, we manually di- ganglia receive input from multiple cortical regions, pass this infor- vided the caudate ROI into head and body subsections based on pre- mation to the thalamus where integration operations occur before in- vious research (Castellanos et al., 1994; Williams et al., 1989). formation is passed to specific cortical regions of one of the Specifically, we designated the boundary between the head and segregated functional circuits (Alexander et al., 1986). Thus, each body of the caudate to be the coronal slice containing the interventri- cycle within a thalamocortical-basal ganglia circuit concludes with cular foramina. The bilateral caudate head ROI was 1677 voxels (left, the thalamocortical pathway terminating in specific regions of the 731 voxels centered at −15, 10, 17; right 946 voxels centered at 15, 9, cortex, unique to that particular loop. To date, these looping circuits 19). The bilateral caudate body ROI was 1803 voxels (left, 904 voxels have not been adequately described in human functional neuroimag- centered at −14, −4, 23; right, 899 voxels centered at 17, −10, 24). ing studies. Topographic mapping within the caudate has been demonstrated BrainMap meta-analysis methods in animal models. Specifically, segmentation of the caudate nucleus into head and body components has revealed consistent, distinct To search for all studies that reported activation within each ROI compartments such that the head of the caudate has been associated boundary, the left and right caudate ROIs were input into the Brain- with more cognitive and emotional processing whereas the body/tail Map database separately, with restrictions to exclude disease-based of the caudate has been associated with action and perceptual pro- studies, and include only activation studies. Whole-brain coordinates cesses. However, similar to the proposed looping circuits, no study of activations from the isolated contrasts were then downloaded (left to our knowledge has tested this organization in humans. caudate=125 papers, 167 experiments, 2466 locations; right cau- Here, we test whether the human caudate connectivity patterns date=135 papers, 200 experiments, 2907 locations). The total num- support the major circuits identified in the nonhuman primate sys- ber of subjects in all studies reporting activation in the left caudate tem, and investigate whether it demonstrates anterior–posterior was 2094, and for the right caudate 2136. Papers were drawn from somatotopic and behavioral topography. Because it is not feasible to all of the behavioral domains coded in the BrainMap database investigate this in a single study, we capitalize on the power of which includes cognition, emotion, action, interoception, pharmacol- meta-analyses and the organization of the BrainMap database (Fox ogy, and perception, with cognition representing the majority of and Lancaster, 2002; Fox et al., 2005; Laird et al., 2005b) database to studies followed by emotion for both the left and right caudate. For 1) identify behavioral domain-specific networks that we predict will more detailed information regarding the taxonomy and coding strat- correspond to the circuits described in the primate literature, and 2) egy of the BrainMap database, please refer to Fox et al. (2005), Laird determine if the anterior and posterior portions of the caudate dem- et al. (2009a, 2011a) and the BrainMap lexicon located