Can the Brain Tell the Difference between Old and New?

In tests of episodic recognition, people are good at discriminating between familiar and novel events (persons, pictures, words, etc.)—even if very many events are presented (Nickerson, 1965) ¹ . This includes correctly saying that something is recognized as ‘old’ as well as correctly saying that something is ‘new’ or non-studied (often referred to as correct rejection). Little is known about the basis for making such old/new decisions. In case of the correct recognition judgment, the interaction between the retrieval cue information and stored information about the event has been emphasized (Tulving, 1983) ² . For the correct rejection judgment, even less is known (but see Kolers & Palef, 1976). At least in part, the lack of knowledge concerning the basis for correct rejections may be due to the fact that it is a very difficult problem to address in cognitive psychology experiments. Important insights can possibly be generated if the problem is addressed from a different angle.