humans are born free of any knowledge and are the sum of their experiences. It wasn't until the late 1800s, however, that a young German philosopher by the name of Herman Ebbinghaus developed the first scientific approach to studying memory. While some of his findings have endured and remain relevant to this day (Learning Curve), his greatest contribution to the field of memory research was demonstrating that memory can be studied scientifically. In 1972, Endel Tulving proposed the distinction between episodic and semantic memory. This was quickly adopted and is now widely accepted. Following this, in 1985, Daniel Schacter proposed a more general distinction between explicit (declarative) and implicit (procedural) memory With the recent advances in neuroimaging technology, there have been a multitude of findings linking specific brain areas to declarative memory. Despite these advances in Cognitive psychology, there is still much to be discovered in terms of the operating mechanisms of declarative memory. It is unclear whether declarative memory is mediated by a particular memory system or if it is more accurately classified as a type of knowledge and it is not known how or why declarative memory evolved to begin with. Neuropsychology Normal brain function Hippocampus Although many psychologists believe that the entire brain is involved with memory, the hippocampus, and surrounding structures appear to be most important in declarative memory specifically. The ability to retain and recall episodic memories is highly dependent on the hippocampus, whereas the formation of new declarative memories relies on both the hippocampus and the parahippocampus. Other studies have found that the parahippocampal cortices were related to superior recognition memory. The Three Stage Model was developed by Eichenbaum, et al. (2001), and proposes that the hippocampus does three things with episodic memory: Mediates the recording of episodic memories Identifies common features between episodes Links these common episodes in a memory space. To support this model, a version of Piaget's Transitive Inference Task was used to show that the hippocampus is in fact used as the memory space. When experiencing an event for the first time, a link is formed in the hippocampus allowing us to recall that event in the future. Separate links are also made for features related to that event. For example, when you meet someone new, a unique link is created for them. More links are then connected to that person's link so you can remember what colour their shirt