Two decades into the 21st century, can we claim to be any closer to a unified model of the brain? In this exploratory symposium, we invite submissions for short talks and posters presenting general mathematical models of brain function. We give priority to those models that account for brain or behavioural data, or provide simulations to that effect. The symposium will be held at the applied mathematics conference ICNAAM 2021, to be held virtually and in person on the island of Rhodes, Greece from the 20-26th of September 2021. Submission is by 250-word abstract before the 30th August, sent to the organizers Prof Dan V. Nicolau Jr ( dan.nicolau@qut.edu.au) and Dr Ruairidh M. Battleday ( battleday@princeton.edu). We already have a great lineup (www.neuromonster.org), and with one week left until the deadline for the abstract submission encourage any remaining interested parties to apply. Ruairidh and Dan -- Dr. Ruairidh McLennan Battleday, BMBCh (Oxon) MA PhD Candidate and Cognitive Science Fellow Computational Cognitive Science Lab, Department of Computer Science Princeton University Department of Statistics St John's College University of Oxford