Project Update 21.04.2020
I have used functional MRI to study the scope of cortical reorganization in patients with advanced glaucoma and controls with simulated visual field deficits. As a primary study, I investigated in visually healthy individuals the influence of experiment stimulus manipulation on the cortical receptive field properties of early and extra-striate visual cortex. The manuscript is currently under review in Neuroimage (preprint available at https://www.biorxiv.org/content/10.1101/2020.01.28.923045v1 ). Currently, I am in the process of finalizing the manuscript of my patient study in glaucoma and retinitis pigmentosa studying the task-dependent modulation in cortical responses in the deafferented visual cortex. The study has the potential to further our understanding on the visual cortex functional organization post visual field loss and can provide insights on the utility of current advances in vision restoration procedures.
To become a principal investigator in visual neuroscience. With the expertise I have gained in neuroimaging through this ESR position, I will pursue a postdoctoral position, where I will investigate, in a comparative approach, an objective assessment of visual acuity with fMRI and VEPs. The main goal of this project is to unlock the correlates behind differential subjective and objective visual acuity estimates in certain patient populations applying a comparative psychophysical, electrophysiological and fMRI approach. As a follow-up to my PhD work, I plan to investigate the previously reported task-dependent fMRI responses in the deafferented visual cortex at the level of cortical layers using ultra-high field (7T) fMRI. This will hopefully provide insights on the nature and source of abnormal cortical responses (feed-forward or feed-back) and answer few questions on ability of visual cortex to reorganize following visual field loss.
My EGRET+ Experience:
The opportunity to be a part of such a dynamic network has been a very rewarding and scientifically enriching experience. The periodic workshops with review of the networks interdisciplinary projects conducted as a part of the program gave me a great opportunity to improve my knowledge not only in my field of research, but in the other complementary research themes and ideas in the field. It also gave me the possibility to network with the leading scientists in the field and the future vision researchers. In addition to the scientific value of these meetings, the focus on personal development has improved my interpersonal skills and given me the confidence to survive in the academic arena. On the whole, personally I am proud to have been a part of this network and I believe this experience to have helped me greatly throughout my PhD at the Otto-von-Guericke University in Magdeburg and prepare myself for a career in science.
Assessment of neural plasticity in glaucoma with high and ultra-high field MRI and fMRI
Prof. Michael Hoffmann (http://www.med.uni-magdeburg.de/augenklinik/vpl/)
Background and Interests
I am Gokulraj Prabhakaran. My fascination towards medical imaging laid the foundation for me to complete my graduation with a Bachelor’s degree in Biomedical Engineering from Anna University, India and pursue a Masters (MSc) in Medical Imaging from the Royal Institute of Technology (KTH), Sweden. In my master thesis titled “Imaging memory encoding in Mild Cognitive Impairment (MCI) using fMRI”, I studied the neural substrates of successful episodic memory encoding in cognitively intact individuals and patients diagnosed with mild cognitive impairment (MCI) to improve our understanding of the pathophysiological mechanisms behind memory decline observed in Alzheimer’s Disease. Then I worked as a research scientist in Mahajan Imaging, India for three years, where I had the opportunity to explore my managerial and administrative abilities of running research studies, in addition to my scientific and technical capabilities. In January 2017, I joined the EGRET+ network as an Early Stage Researcher at the Otto-von-Guericke University, Magdeburg, Germany.
In order to get a deeper understanding of the mechanism behind glaucoma and its progression, it is important to study the disease from the perspective of both an eye disease and a brain disorder. With an already well established knowledge of retinotopic organization of the normal visual cortex, the major goal of this project would be to determine whether (long term) deprivation of peripheral visual input observed in glaucoma compromises the structural and functional integrity of the visual cortex, using high and ultra-high field MRI and fMRI and computational models.