In this chapter, I examine various cognitive changes or innovations realized by specific cognitive mechanisms that could explain both what made possible the emergence of representations from non-representational indices, and, also, what allowed the brain to be able to support icons and symbols. It is understood that these mechanisms survived because they played an adaptive role in the evolution of our species. To play such a role, these mechanisms must have enabled functional capacities that were advantageous for the survival of our species. This means that not only were these new functional capacities a successful answer to some environmental and cultural pressures, but also that the mechanisms that enabled them were best suited to fulfill these functions compared to other cognitive mechanisms that could have performed these same functions. Hence, I discuss the cognitive prerequisites that allowed our ancestors to move from indices (which is the first form of non-representational signs used) to representations the first form of which was that of iconic representations. I also briefly address the problem of what necessitated the emergence of representational capacities, that is, why having representations was in evolutionary terms beneficial to a species.