Elements of episodic memory: lessons from 40 years of research.

40 years ago, Endel Tulving published his hugely influential Elements of Episodic Memory (Oxford: Clarendon Press, 1983). For the first time, this discussed the details of episodic memory (i.e. the ability to remember personal past events), including a specific conscious experience. Ten years later, Tulving defined the ability to mentally project oneself in time to be the critical feature distinguishing episodic from semantic memory ('What is episodic memory?' Curr . Dir . Psychol . Sci . 2 , 67-70, doi:10.1111/1467-8721.ep10770899). In this conception, the conscious experience of episodic memory captures the experience of reliving a personal event as it was experienced in the past, while the same ability allows a potential symmetry between remembering the past, and our ability to project into an imagined future. With the recent passing of Endel Tulving, this theme issue offers an opportunity to question our understanding of mental time travel in full.This article is part of the theme issue 'Elements of episodic memory: lessons from 40 years of research'.