Posts classified under: Affinity Groups

David Clewett, Ph.D.

Research and Teaching Interests:

In everyday life, we encounter a continuous stream of information. Yet, because our mental resources are limited, we cannot process and remember everything we experience. This raises two critical questions: How do we prioritize and store important information in memory? How do unfolding experiences become organized into memories of meaningful events? My research examines the brain mechanisms that support these adaptive memory processes.

A key theoretical construct motivating my work is that physiological arousal plays a fundamental role in facilitating attention and memory. Decades of research show that people perceive and remember emotionally arousing events better than more mundane events. For example, experiencing a car crash or celebrating a birthday tend to be more memorable than a routine commute to work. Beyond simply enhancing processing of the emotional information, however, a surge in arousal can also spillover to enhance or impair processing of nearby neutral information. Spikes in arousal are also happening all the time and not just in response to emotional events. Consequently, even as everyday experiences unfold, arousal states may play a lead role in determining whether an event will be forgotten or etched into memory more permanently.

My research seeks to understand how arousal responses – particularly those elicited by emotional, stressful or motivating (rewarding/threatening) situations – influence: (1) what we remember: the information we selectively attend to and remember later on; (2) how we remember: the way in which memories become organized and updated over time; and (3) when we remember: certain neurochemical and brain states, such as elevated norepinephrine and dopamine release, that are induced before, during or after an event. To study these topics, my lab takes a multi-modal approach that includes functional and structural neuroimaging (fMRI/MRI/DTI), neurophysiology (eye tracking and hormone assays), pharmacology, and behavioral methods.


David Clewett will join UCLA as an Assistant Professor of Psychology in July 2020. He received his PhD in Neuroscience from the University of Southern California in 2016, where he worked with Dr. Mara Mather to study emotion-cognition interactions. He then conducted a postdoctoral fellowship with Dr. Lila Davachi at NYU and Columbia University, where he studied how episodic memories are constructed from continuous experience. Before attending graduate school, he received a B.S. degree in Biopsychology with a minor in English from the University of California, Santa Barbara.


  • Clewett, D.* & Murty, V.* (in press). Echoes of emotions past: How neuromodulators determine what we recollect. ENeuro. *authors contributed equally
  • Clewett, D., Dubrow, S., & Davachi, L. (2019). Transcending time in the brain: How event memories emerge from experience. Hippocampus, 29(3), 162-183.
  • Clewett, D., Huang, R., Velasco, R., Lee, T.H., & Mather, M. (2018). Locus coeruleus activity strengthens prioritized memories under arousal. Journal of Neuroscience, 38(6), 1558-1574.
  • Clewett, D., & Davachi, L. (2017). The ebb and flow of experience determines the temporal structure of memory. Current Opinion in Behavioral Sciences, 17, 186-193.
  • Clewett, D., Sakaki, M., Huang, R., Nielsen, S., & Mather, M. (2017). Arousal amplifies biased competition between high and low priority memories more in women than in men: the role of elevated noradrenergic activity. Psychoneuroendocrinology, 80, 80-91.
  • Clewett, D., Sakaki, M., Nielsen, S., Petzinger, G., & Mather, M. (2017). Noradrenergic mechanisms of arousal’s bidirectional effects on episodic memory. Neurobiology of Learning and Memory137, 1-14.
  • Mather, M., Clewett, D., Sakaki, M., & Harley, C. (2015). Norepinephrine ignites local hot spots of neuronal excitation: How arousal amplifies selectivity in perception and memory. Behavioral and Brain Sciences, 1-100.

Xia Yang, Ph.D.


Dr. Xia Yang received her Ph.D. in Molecular Genetics and Bioinformatics from Georgia State University and had postdoctoral training in Systems Genetics at UCLA. She was Senior Research Scientist at Rosetta Inpharmatics/Merck & Co. and Director of Systems Biology at Sage Bionetworks prior to returning to UCLA as a faculty member.

Research Interests

Our research focuses on developing and applying multitissue multiomics systems biology approaches to dissect the molecular networks underlying diverse complex diseases, ranging from cardiometabolic diseases to neurodegenerative and neurological disorders, and utilize the systems level networks to guide precision medicine. Through integration of genetic, transcriptional, epigenomic, proteomic, gut microbiota, and phenotypic data from human and rodent populations, we investigate how complex interactions between genetic and environmental risk factors perturb tissue- and cell-specific gene networks which in turn induce variations in disease susceptibility. Subsequently, we use the causal molecular networks of diseases as the basis for therapeutic target identification and biomarker discovery.



B.S., Pharmacy, Shandong University 1993
Ph.D., Molecular Genetics/Bioinformatics, Georgia State University 2003


Selected Publications

Yang X. “Multi-tissue Multi-omics Systems Biology to Dissect Complex Diseases”. Trends in Molecular Medicine, 2020.

Liu W, Venugopal S, Majid S, Ahn IS, Diamante G, Hong J, Yang X*, Chandler SH*. “Single-cell RNA-seq Analysis of the Brainstem of Mutant SOD1 mice Reveals Perturbed Cell Types and Pathways of Amyotrophic Lateral Sclerosis”. Neurobiology of Disease, 141: 104877, 2020.

Rajbhandari P+, Arneson D+, Feng AC, Ahn IS, Diamante G, Zaghari N, Thomas BJ, Vergnes L, Lee SD, Reue K, Smale ST, Yang X, Tontonoz P. “Single Cell Analysis Reveals Immune Cell-Adipocyte Crosstalk Regulating the Transcription of Thermogenic Adipocytes”. eLife 8:e49501, 2019.

Zhang G, Byun HR, Ying Z, Blencowe M, Zhao Y, Hong J, Shu L, Gomez-Pinilla F, Yang X. “Differential Metabolic and Multi-tissue Transcriptomic Responses to Fructose Consumption among Genetically Diverse Mice”. BBA – Molecular Basis of Disease. 1866: 165569, 2020.

Shu L, Meng Q, Tsai B, Diamante G, Chen Y, Mikhail A, Luk H, Ritz B, Allard P, Yang X, “Prenatal Bisphenol A Exposure in Mice Induces Multi-tissue Multi-omics Disruptions Linking to Cardiometabolic Disorders”, Endocrinology, 160 : 409-429, 2019.

Arneson D, Zhuang Y, Byun HR, Ahn IS, Ying Z, Zhang G, Gomez-Pinilla F, Yang X, “Single Cell Molecular Alterations Reveal Pathogenesis and Targets of Concussive Brain Injury”, Nature Communications, 9 : 3894, 2018.

Emilsson V, llkov M, Lamb JR, Finkel N, Gudmundsson EF, Pitts R, Hoover H, Jennings LL, Horman SR, Aspelund T, Shu L, Trifonov V, Gudmundsdottir V, Sigurdsson S, Manolescu A, Zhu J, Lesley SA, To J, Zhang J, Harris TB, Launer LJ, Zhang B, Eiriksdottir G, Yang X, Smith AV, Orth AP, Gudnason V, “Coregulatory Networks of Human Serum Proteins Link Genetics to Disease”, Science, 361 : 769-773, 2018.

Kurt Z, Barrere-Cain R, LaGuardia J, Mehrabian JM, Pan C, Hui ST, Norheim F, Zhou Z, Hasin Y, Lusis AJ, Yang X, “Tissue-specific Pathways and Networks Underlying Sexual Dimorphism in Non-Alcoholic Fatty Liver Disease”, Biology of Sex Differences, 9 : 46- (2018) .

Krishnan KC, Kurt Z, Barrere-Cain R, Sabir S, Das A, Floyd R, Vergnes L, Zhao Y, Che N, Charugundla S, Qi H, Zhou Z, Meng Y, Pan C, Seldin MM, Norheim F, Hui S, Reue K, Lusis, AJ, Yang X., “Integration of Multi-omics Data from Mouse Diversity Panel Highlights Mitochondrial Dysfunction in Non-Alcoholic Fatty Liver Disease”, Cell Systems, 6 : 1-13, 2018.

Shu L, Chen KHK, Zhang G, Huan T, Kurt Z, Zhao Y, Codoni V, Tregouet DA, Yang J, Wilson JG, Luo X, Levy D, Lusis AJ, Liu S, Yang X, “Shared Genetic Regulatory Networks for Cardiovascular Disease and Type 2 Diabetes in Multi-ethnic Populations”, PLOS Genetics, 13 (9): e1007040, 2017.