A Neuropsychological Model of Memory and Consciousness

In my contribution to the first edition of this volume, I avoided speculating about different kinds of memory. Instead, I concentrated on identifying the sufficient conditions for distinguishing between memory tests on which performance of amnesic patients is relatively intact and those on which it is impaired (Moscovitch, 1984). Those conditions are the basis of the current distinction between explicit and implicit tests of memory (Graf & Schacter, 1985). In the years since the book appeared, the theoretical and empirical literature on this topic has burgeoned as no other has done in cognitive psychology and neuropsychology. One of the main consequences of this enterprise has been a growing appreciation both of the varieties of memory and of the component cognitive processes and neurological mechanisms that underlie them (RichardsonKlavehn & Bjork, 1988; Roediger & Craik, 1989). The operational, descriptive approach I adopted in my previous chapter is still useful in classifying memory tests, but it is no longer adequate in dealing with the rich theoretical and empirical literature we now have. I therefore supplement it with (in fact, subordinate it to) theoretical speculations about the varieties of memory in normal and brain-damaged people.