Recovered consciousness: a hypothesis concerning modularity and episodic memory.

Why should conscious recollection be associated with recovery of some memories and not others? A hypothesis is proposed and defended that the medial temporal lobe/hippocampal complex (MTL/H) and related limbic structures comprise a memory module that receives as its input only information that is consciously apprehended. The module then binds or conjoins into memory traces those neural elements that mediated the conscious experience so that effectively "consciousness" is as intergral a part of the memory traces as it was during the experience of the event. When memory traces are retrieved, what is recovered are the phenomenological records (Conway, 1992) of experienced events which are integrated content-consciousness packets. Evidence is presented which suggests that the MTL/H module satisfies Fodorian criteria of modularity. The MTL/H module is compared to perceptual modules in nonfrontal neocortex that mediate performance on tests of memory without awareness and to prefrontal neocortex that acts as a central working-with-memory system that operates on the input to MTL/H and the shallow output from it.