In animals, short-term memories generated by weak behavioural training can be strengthened and converted to long-term memories by a subsequent novel experience, such as exposure to a new environment. The authors here showed that a similar phenomenon occurs in humans: participants' recollection of otherwise neutral objects was enhanced if other objects from the same conceptual category (in this case, tools or animals) were subsequently paired with an electric shock. Such selective consolidation of memories that are associated with meaningful events may explain why we are able to remember specific, but otherwise unimportant, episodic details of emotional experiences.