Medical Research: What is the background for this study? What are the main findings?
Dr. Tsvetanov: Older brains may be more similar to younger brains than previously thought! In our study we have shown that changes in the aging brain previously observed using functional magnetic resonance imaging (fMRI) – one of the standard ways of measuring brain activity – may be due to changes in our blood vessels, rather than changes in the activity of our nerve cells, our neurons. Given the large number of fMRI studies used to assess the aging brain, this has important consequences for understanding how the brain changes with age and it challenges current theories of ageing.
Medical Research: What are the main findings?
Dr. Tsvetanov: The study addresses fMRI issues of measuring neural activity indirectly through changes in regional blood flow. Without careful correction for age differences in vascular reactivity, differences in fMRI signals can be erroneously regarded as neuronal differences. The unique combination of an impressive multimodal data set across 335 healthy volunteers over the lifespan, as part of the CamCAN project (www.cam-can.com), allowed my colleagues and I to validate a method for correction, which is suitable for fMRI studies of aging. Our findings clearly show that without such correction methods, fMRI studies of the effects of age on cognition may misinterpret effect of age as a neurocognitive, rather than neurovascular, phenomena.
The study was funded by BBSRC, the Medical Research Council and the Wellcome Trust.
About Cam-CAN: The Cambridge Centre for Ageing and Neuroscience (Cam-CAN) is a large-scale collaborative research project, launched in October 2010, with substantial funding from the Biotechnology and Biological Sciences Research Council (BBSRC). Combining expertise from multiple fields, over 30 researchers, collaborators and their teams from the Departments of Psychology, Public Health and Primary Care, Psychiatry, Clinical Neurosciences, and Engineering in the University of Cambridge and the Medical Research Council Cognition and Brain Sciences Unit are working together examine key research questions about lifelong health and development, aiming to understand how individuals can best retain cognitive abilities into old age. Cam-CAN includes a large population-based sample of adults aged 18-88yrs, and uses a unique and powerful approach which integrates multiple domains including epidemiology, cognitive psychology, and neuroimaging. The research aims to understand brain-cognition relationships across the lifespan and how these impact on cognitive function, to determine the extent of neural flexibility and the potential for neural reorganisation to preserve cognitive functions and, crucially, to change the perspective of ageing in the 21st century by highlighting the importance of abilities that are maintained into old age. www.cam-can.com
Citation: Kamen A. Tsvetanov, Richard N. A. Henson, Lorraine K. Tyler, Simon W. Davis, Meredith A. Shafto, Jason R. Taylor, Nitin Williams, Cam-CAN, and James B. Rowe (2015). The effect of ageing on fMRI: correction for the confounding effects of vascular reactivity evaluated by joint fMRI and MEG in 335 adults. Human Brain Mapping – Available at: http://onlinelibrary.wiley.com/doi/10.1002/hbm.22768/abstract
MedicalResearch.com Interview with:, & Kamen Tsvetanov, PhD (2015). Human Brains Age Less Than Previously Thought MedicalResearch.com