Reply to Baker and Holtom

Reply to Baker and Holtom.

TO THE EDITOR—We thank Drs Baker and Holtom [1] for their thoughtful comments on the low number of smear-negative, culture-positive tuberculosis cases in our study [2] and another recent study [3] of the GeneXpert MTB/RIF assay (Xpert). They astutely point out that this may have led us to underestimate the potential benefit of Xpert in low-burden settings. We agree that the incremental sensitiv...

Are we essentially persons? Olson, Baker, and a reply.

In the literature on persons and their identity, it is customary to distinguish the issue of the nature of personhood—“What is a person?”—from the issue of personal identity—“What are the persistence conditions of a person over time?” In recent years, Eric Olson and Lynne Rudder Baker have brought to the forefront of discussion the related, but often neglected, issue of our essence: “What are w...

Reply from C. L. Witham and S. N. Baker

We thank Drs Schouten and Campfens for their interest in our paper. We are more optimistic about the practical capabilities of directed coherence than the position they adopt in their letter, but we would also emphasise the need for caution in using these methods. At the basis of directed coherence (Granger causality) methods is an autoregressive model of the signals of interest. For the bivari...

Changes in brain structure during learning: Fact or artifact? Reply to Thomas and Baker

In their review in this issue, Thomas and Baker question the validity of longitudinal human neuroimaging studies that have claimed to demonstrate structural plasticity. This commentary identifies problems with some of the arguments raised in their review and suggests that there is strong evidence, from both animal and human studies, that experience can alter brain structure.

The Authors’ Reply