Great Success for Renato Duarte

Renato Duarte is feeling relieved. “This doctorate degree was my chance to push myself far beyond my limits and having successfully completed it makes me feel very proud”, he says after the evaluation process is over. Renato Duarte started his dissertation career within the PhD Program EuroSPIN at the Bernstein Center Freiburg. He was supervised by Abigail Morrison, who was a Junior Professor at the BCF during this time.

“This doctoral program gave me everything I hoped for and much, much more”, summarizes the 34-year-old researcher from Portugal. “I was fortunate enough to experience world-class research centers and learn about state-of-the-art computational neuroscience from some of the best in the field. As an added bonus, I also got the chance to travel all over the world and to network with some amazing people.”

Among the places he visited, Renato Duarte spent research time in Edinburgh and Bochum and in 2014 he followed Abigail Morrison to the Jülich Research Center. “I believe computational neuroscience is the most promising approach to really answer the big questions and systematically uncover basic functional principles. It allows us to understand how different aspects of neurobiological systems interact to cause high-level cognition and behavior”, says the young scientist. Explaining his passion for Computational Neuroscience, “I am absolutely fascinated by the brain.”

Now he has the chance to advance his research as a postdoc at the Jülich Research Center. In the future, his primary focus will be on synaptic adaptation, learning and memory in distributed neocortical hierarchies.

Summary of the PhD-Thesis
Many different aspects of cognitive function express themselves as structured temporal sequences. On the other hand, several important organizational principles of the neocortex appear to imply a strong predisposition to acquire this temporal structure in a completely incidental/unsupervised manner.

Throughout this thesis, we have explored the processes involved in implicit, structured sequence learning in biologically-inspired architectures in order to evaluate the character of on-line processing memory and finite precision computation in systems where the current state continuously interacts with and modifies the processing characteristics. We have demonstrated a prominent role of synaptic plasticity (particularly of inhibitory synapses) in representational and rule-guided learning, an effect achieved by maintaining compact dynamic representations and sparse, distributed activity patterns.

We have highlighted a form of sequential metastability as a potential mechanism for sequence learning in neocortical circuits. In addition, we discuss how innate constraints in the patterning of the synaptic machinery throughout the neocortex may bias a circuit's intrinsic timescales and memory capacity, while the high degree of complexity and heterogeneity may serve important computational purposes by expanding the circuit's functional space.

Selected publications
Renato Duarte and Abigail Morrison.
Dynamic stability of sequential stimulus representations in adapting neuronal networks.
Frontiers in Computational Neuroscience, 8(October):124, 2014

Renato Duarte, Alexander Seeholzer, Karl Zilles, and Abigail Morrison.
Synaptic patterning and the timescales of cortical dynamics.
Current Opinion in Neurobiology, 43:156–165, 2017

Contact
Jülich Research Center
Renato Duarte
Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA Institute Brain Structure-Function Relationships (INM-10)
Phone: +49 2461 61-8911
E-mail: r.duarte@fz-juelich.de