Representing the past: memory traces and the causal theory of memory

According to the Causal Theory of Memory (CTM), remembering a particular past event requires a causal connection between that event and its subsequent representation in memory, specifically, a connection sustained by a memory trace. The CTM is the default view of memory in contemporary philosophy, but debates persist over what the involved memory traces must be like. Martin and Deutscher (Philos Rev 75:161-196, 1966) argued that the CTM required memory traces to be structural analogues of past events. Bernecker (Memory: A philosophical study. Oxford University Press, Oxford, 2010) and Michaelian (Philos Psychol 24:323-342, 2011), contemporary CTM proponents, reject structural analogues in favor of memory traces as distributed patterns of event features. The proposals are understood as distinct accounts of how memory traces represent past events. But there are two distinct questions one could ask about a trace's representational features. One might ask how memory traces, qua mental representations, have their semantic properties. Or, what makes memory traces, qua mental representations of memories, distinct from other mental representations. Proponents of the CTM, both past and present, have failed to keep these two questions distinct. The result is a serious but unnoticed problem for the CTM in its current form. Distributed memory traces are incompatible with the CTM. Such traces do not provide a way to track the causal history of individual memories, as the CTM requires. If memory traces are distributed patterns of event features, as Bernecker and Michaelian each claim, then the CTM cannot be right.