Often factors related to hippocampal neurogenesis also result in a myriad of confounding changes that might explain or mediate the concomitant effects in memory and learning performance. Dr. Lazic's article (2010) reiterates such concerns in interpreting the biological links between neurogenesis and learning in the context of aging as articulated previously by Baxter and Gallagher (2006). The correlative analysis published by Nyffeler et al. (2008) illustrates the problematic inherent to such an interpretation. We offer here a complimentary approach that is both intuitive and practical in the re-examination of the previously reported data set, which further supports Nyffeler et al.'s (2008) key findings and conclusion.
- Partial correlation statistics