Title Locus coeruleus neuromelanin predicts ease of attaining and maintaining neural states of arousal Authors and Affiliations Sana Hussain 1 , Isaac Menchaca 1 , Mahsa Alizadeh Shalchy 3 , Kimia Yaghoubi 3 , Jason Langley 2 , Aaron R. Seitz 3 , Xiaoping P. Hu 1,2† , Megan A. K. Peters 1,4† 1. Department of Bioengineering, University of California Riverside, Riverside, CA 2. Center for Advanced Neuroimaging, University of California, Riverside, Riverside, CA 3. Department of Psychology, University of California Riverside, Riverside, CA 4. Department of Cognitive Sciences, University of California Irvine, Irvine, CA † These authors contributed equally to this work Sana Hussain ORCID: 0000-0003-0986-2654; email: shuss006@ucr.edu Isaac Menchaca ORCID: 0000-0003-2912-2178; email: imenc001@ucr.edu Mahsa Alizadeh Shalchy ORCID: 0000-0002-6576-9115; email: maliz001@ucr.edu Kimia Yaghoubi ORCID: 0000-0002-6806-2617; email: kyagh001@ucr.edu Jason Langley ORCID: 0000-0001-9412-1265; email: jason.langley@ucr.edu Aaron R. Seitz ORCID: 0000-0003-4936-9303; email: aseitz@ucr.edu Xiaoping P. Hu ORCID: 0000-0001-7014-5983; email: xhu@engr.ucr.edu Megan A. K. Peters ORCID: 0000-0002-0248-0816; email: megan.peters@uci.edu Word count: 10,609 (excluding abstract, references, figure captions, and appendices) Figures/Tables: 7 Figures/7 Tables (excluding appendices) † Correspondence should be addressed to: Megan A. K. Peters, Ph.D. Assistant Professor, Cognitive Sciences, University of California, Irvine Social & Behavioral Sciences Gateway 2314 Phone: (949) 824-6692 Fax: (949) 824-2307 E-mail: megan.peters@uci.edu Xiaoping P. Hu, Ph.D. Provost Fellow Professor and Chair, Department of Bioengineering, University of California, Riverside Materials Science and Engineering 205 Phone: (951) 827-2925 Fax: (951) 827-6416 E-mail: xhu@engr.ucr.edu 1 . CC-BY-ND 4.0 International license available under a (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted March 8, 2022. ; https://doi.org/10.1101/2022.03.07.483289 doi: bioRxiv preprint