1. It might seem strange to talk about the spinal cord and memory, but this has recently received some attention in the study of chronic peripheral pain. In fact, the same molecular mechanisms involved in cortical and hippocampal long-term potentiation underlie the experience-driven synaptic plasticity hypothesized to explain features of chronic pain. See Sufka (2001) for a clear exposition of this hypothesis.
2. lf these scientific details elude you now, fear not. Later in this chapter I’ll explain in detail the molecular mechanisms of LTP and experimental protocols and results in studies of this sort. For novices, I’ll even include a brief “primer” on basic cellular neuroscience.
3. Schouten and de Jong inform me that this argument in their (1999) was intended to reveal the cross-categorizations that obtain between psychological and neurobiological concepts, rendering any sort of “bottom-up” explanatory approach untenable. If so, then their argument rests upon issues I will take on in Chapter Three, namely, questions about methodology within neuroscience dominated by the search for cellular and molecular mechanisms and the issue of multiple realization.
4. Many readers will be familiar with well-known exceptions to the stimulus repetition feature. One-trial learning that remains stable for long periods has been studied for more than four decades. Typically, these are species-specific and evolutionarily prominent learning processes, e.g., conditioned taste aversions in rats. See, e.g., Garcia and Koelling (1966) (although most reputable learning theory textbooks will include a description of this phenomenon). For ease of exposition, I won’t be qualifying the “stimulus repetition” condition on consolidation in the discussion to follow. Fans of one trial learning can make the appropriate mental adjustments to my assertions, e.g., that stimulus repetition and rehearsal typically improves long-term memory recall and performance. Thanks to Carl Craver for pointing out the need to qualify some remarks I make in the discussion below.
5. This study is summarized nicely in Squire and Kandel 1999, 130–132.