Turhan Canli, Ph.D.
Yale University (1993)
Prof. Canli plans to admit a new graduate student pending approval of funding.
I am interested in understanding the interplay of environmental and genetic factors that shape individual differences in emotions, personality traits, social cognition, and mental health. I seek to apply the insights we glean from this work to the larger world, in the context of neuroethics and global brain health.
In earlier work, I conducted the first functional MRI studies on individual differences in subjective emotional experiences , personality traits [2, 3], sex differences in emotional memory , and the first study on a gene-by-environment interaction related to the serotonin transporter gene polymorphism (HTTLPR) and life stress . A decade-and-a-half later, I conducted the first studies on genome-wide expression patterns related to loneliness in the human brain [6, 7].
I use the term “molecular psychology” to describe my approach, which is to view individual differences in behavior and its underlying brain structure and function through the lens of molecular biology, particularly the structure and regulation of the genome. This includes gene polymorphisms, which were the focus of the first generation of “candidate gene studies” [5, 8, 9], but goes well beyond that, by including mechanisms related to variation in transcription (such as alternative splicing) and translation (such as post-translational modifications), epigenetic mechanisms and regulatory functions of the non-coding genome (such as microRNAs, retrotransposons and endogenous retroviruses). I published the first handbook on the topic in 2015, TheOxford Handbook of Molecular Psychology , and launched the first journal in 2022, Molecular Psychology: Brain, Behavior, & Society . I am now writing the first undergraduate textbook on the subject, Molecular Psychology: Discovering the Mechanisms that regulate Genes, Brains, and Behavior (under contract with Routledge, anticipated release date 2024). This approach shaped my thinking about aspects of the human genome that most psychologists are unfamiliar with, such as the epigenetic regulation of ancient human endogenized retroviruses (HERVs) that make up 8% of our DNA, and their role in fundamental aspects of brain function and mental health and illness.
Beyond the laboratory, I want to make sure that neuroscience can have a positive societal impact. In 2006, was a co-founder of the International Neuroethics Society (neuroethicssociety.org), which examines the ethical, legal, and societal implications of advances in neuroscience, and served on its executive board from 2006-2015. In 2017, I earned a Certification in Global Mental Health: Refugee Trauma and Recovery from Harvard Medical School and have since then worked on various projects related to refugee mental health .
Current Research Interests:
- What is the role of the blood-brain barrier in depression, aging, and long-COVID cognitive and affective symptoms? At the SCAN (Social, Cognitive/Clinical, and Affective Neuroscience) Center that I founded and direct since 2008, we recently developed a novel non-invasive imaging technique to measure water movement across active channels in the blood-brain barrier (BBB) . We are in the process of applying this exciting new technology to better understand how changes in the BBB predict depressive state, cognitive decline, and long-COVID cognitive and affective symptoms. This work will lay the foundation for novel models of the molecular mechanisms of BBB permeability that contribute to disease vulnerability and progression. Such models could open the door for the development of a new class of prognostic and diagnostic biomarkers, prophylactics and therapeutics.
- What role, if any, do human endogenous retroviruses (HERVs) play in conferring individual differences in brain function? This work is related to the previous topic, because some HERVs affect the BBB, but there are so many of them (more than 500,000, most of which have not been systematically studied) that there is much to be discovered about their function. Simply put: these HERVs have been embedded in our DNA for millions of years and therefore coevolved with our (and any other living) species. Currently, we still know very little about the neurobiological significance, scope, and depth of this coevolution.
- Political, Climate, and ‘Big Issues’ Cognition. In current pilot work, we ask questions about cognition related to political decision-making, such as during the processing of “fake news”. Does one encode or remember information contained in fake news differently, depending on one’s own political bias, even when one knows that the news is fake? We plan to expand our work on this kind of decision-making to other large social questions, such as agency in climate change: is there a switch that flips in one’s mind from “this problem is too big – there is nothing I can do anyway” to “I’ve got to do something!”? What are the parameters of the decision-making space that need to be modified to get a person to switch from a state of inaction to action?
- Global Brain Health. Pending funding, we plan a new initiative on global brain health, focusing on environmental and biological mechanisms across different populations in Africa and comparing them to US-based African-American populations. This work will include environmental stressors such as racial discrimination and trauma from war and forced displacement among refugees.
Canli T. Molecular Psychology: Discovering the Mechanisms that regulate Genes, Brains, and Behavior. Routledge (under contract, release anticipated in 2024).
Canli T. (Editor). The Oxford Handbook of Molecular Psychology. New York, Oxford: Oxford University Press; 2015.
Canli T. (Editor). Biology of Personality and Individual Differences. New York: Guilford Press; 2006.
- Canli, T., et al., Hemispheric asymmetry for emotional stimuli detected with fMRI. Neuroreport, 1998. 9(14): p. 3233-3239.
- Canli, T., et al., An fMRI study of personality influences on brain reactivity to emotional stimuli. Behavioral Neuroscience, 2001. 115(1): p. 33-42.
- Canli, T., et al., Amygdala response to happy faces as a function of extraversion. Science, 2002. 296(5576): p. 2191.
- Canli, T., et al., Sex differences in the neural basis of emotional memories. Proceedings of the National Academy of Sciences of the United States of America, 2002. 99(16): p. 10789-94.
- Canli, T., et al., Neural correlates of epigenesis. Proceedings of the National Academy of Sciences of the United States of America, 2006. 103(43): p. 16033-8.
- Canli, T., et al., Differential transcriptome expression in human nucleus accumbens as a function of loneliness. Molecular psychiatry, 2017. 22(7): p. 1069-1078.
- Canli, T., et al., Loneliness 5 years ante-mortem is associated with disease-related differential gene expression in postmortem dorsolateral prefrontal cortex. Translational Psychiatry, 2018. 8(1): p. 2.
- Canli, T., et al., Beyond affect: A role for genetic variation of the serotonin transporter in neural activation during a cognitive attention task. Proceedings of the National Academy of Sciences of the United States of America, 2005. 102(34): p. 12224-12229.
- Canli, T. and K.-P. Lesch, Long story short: the serotonin transporter in emotion regulation and social cognition. Nature neuroscience, 2007. 10(9): p. 1103-9.
- Canli, T., ed. The Oxford Handbook of Molecular Psychology. 2015, Oxford University Press: New York, Oxford.
- Canli, T., 25 years of Molecular Psychology: The best is yet to come. Molecular Psychology: Genes, Behavior & Society, 2022.
- Canli, T. Refugee Mental Health Through the Lens of Neuroscience and Genetics. EuropeNow, 2017.
- Wengler, K., et al., 3D MRI of whole-brain water permeability with intrinsic diffusivity encoding of arterial labeled spin (IDEALS). NeuroImage, 2019. 189: p. 401-414.