An enhanced mixture method for constructing gatekeeping procedures in clinical trials.

It is increasingly common to encounter complex multiplicity problems with several multiplicity components in confirmatory Phase III clinical trials. These components are often based on several endpoints (primary and secondary endpoints) and several dose-control comparisons. When constructing a multiplicity adjustment in these settings, it is important to control the Type I error rate over all multiplicity components.

Conditions required for binocular rivalry suppression.

When the two eyes are presented with incompatible stimuli, the two monocular stimuli are seen alternately in a never-ending cycle. It is now widely accepted that the neural processes underlying this phenomenon, binocular rivalry, are distributed across a number of cortical stages. It is not clear, however, where binocular rivalry is initiated.

Contrast sensitivity of form and motion discrimination during binocular rivalry.

Binocular rivalry, which is induced by presenting the two eyes with incompatible stimuli, results in periods where one eye's stimulus is seen and the other stimulus is suppressed. We measured the depth of suppression in two ways, with very different results. First, two similar forms were briefly presented to one eye: the difference in shapes required to discriminate the forms was substantially greater during suppression than during dominance.

A Cartesian coordinate system for human cerebral cortex.

The most commonly used method for specifying the locations of functional areas in the human cerebral cortex is the coordinate system of Talairach and Tournoux (Co-planar Stereotaxic Altas of The Human Brain (1988) Georg Thieme Verlag, Stuttgart). It was designed to locate subcortical nuclei by reference to an axis joining the anterior and posterior commissures. The coordinate system has difficulties, however, when applied to cortical locations: (1) it can be difficult to locate the posterior commissure (PC); (2) the fundamental axis is short, and errors in specifying the axis lead to large errors at the cortical surface; (3) there is no normalisation for brain size.