In this chapter, we delve into the intriguing world of memory development, from infancy to adulthood. We begin by emphasizing the fundamental role memory plays in learning. We explore two distinct memory systems: one we are conscious of and another that operates behind the scenes. We examine various memory types, their testing methods, and the brain regions responsible for them. Our focus then shifts to episodic memory, questioning its exclusivity to humans. We dissect the brain structures involved in memory formation and their developmental changes. Additionally, we explore the interconnectedness of memory, thinking processes, and decision-making. Our goal in this chapter is to provide a comprehensive understanding of memory development across different life stages, laying the groundwork for a deeper grasp of this intricate cognitive process.

The hippocampus of mammals, birds, reptiles, and amphibians is a fundamental brain structure for certain forms of relational memory. We review here the experimental evidence indicating that the hippocampal pallium of teleost fish, like the hippocampus of land vertebrates, is involved in relational map-like spatial memory, endowing fish behavior with the capability for allocentric navigation and allowing the flexible expression of spatial memory. In addition, recent evidence suggests that the teleost fish hippocampal pallium plays an important role in the processing of the temporal dimensions of relational memory. The functional similarities in the hippocampal pallium of taxa that diverged millions of years ago suggest the possibility that some features of the hippocampal networks allowing the processing of the spatial as well the temporal dimensions of relational associative memories appeared early in vertebrate evolution and were conserved through phylogenesis.