The Perspectives in Neuroscience Seminar Series 2015-16 edition kicked off this past Thursday, September 24th with an engaging lecture by Dr. Mark D’Esposito of UC Berkeley. After spending some time convincing the UC Davis group of neuroskeptics that fMRI can, and does indeed, pick up on segregated patterns of activity across the brain, Dr.D’Esposito shared his lab’s data on the modular (yet integrated) brain. His research team assessed whole-brain network structure in a set of patients with various types of focal brain lesions. Interestingly, those lesions found in areas deemed “connectors” (important hubs facilitating between-network communication) resulted in greater changes in the overall network structure of the brain than did lesions of comparable size elsewhere (i.e. not connectors). Furthermore, the local perturbation in one hemisphere of the brain had widespread effects on the rest of the network as a whole. In the words of Gratton and Nomura:
“These findings fundamentally revise our understanding of the remote effects of focal brain damage and may explain numerous puzzling cases of functional deficits that are observed following brain injury.” – Journal of Cognitive Neuroscience, 24(6):1275-85, 2012
Thus, despite the time spent discussing the modularity of different brain networks and areas, the inevitable fact that networks are also, undeniably, connected to one another remains. Or in Dr. D’Esposito’s own words: “to summarize, the brain is mostly modular”. Importantly, however, this modular view has real clinical implications. For example, in a more recent study conducted by his research team, modularity is predictive of patient responsiveness to cognitive brain training. Additionally, the lesions found at specific “connectors” are linked to various predictable brain diseases. Work is still ongoing.
After the lecture, a group of graduate students and post docs had the opportunity to have lunch with Dr.D’Esposito and pick his brain about training students, running a lab, setting up a synergistic team, and measuring your success as a scientist.
It was a strong start to our Perspective in Neuroscience Seminar Series (which we will be indexing on Twitter using hashtag #PINSS15 from now on, so stay tuned!) A link to the schedule of upcoming talks in the series can be found here.