In the final discussion of our series on Stephen Grossberg's approach to neuroscience, we look at the GRIDSMap model of the emergence of the hexagonal pattern of grid cell firing, developed along with Himanshu Mhatre and Anatoli Gorchetchnikov. Topics include: navigation, hippocampal place cells, entorhinal grid cells, head direction cells and the vestibular system. ___ Session held on January 26, 2022. Organized by Yohan J. John