We have reviewed the evidence that processes and functions related to perception and expression of emotions are represented asymmetrically in the cerebral hemispheres. The literature describes three possible aspects of emotional lateralization: that emotions are better recognized by the right hemisphere; that control of emotional expression and related behaviors takes place principally in the right hemisphere; and that the right hemisphere is specialized for dealing with negative emotions, while the left is specialized for dealing with positive emotions. Evidence for the three hypotheses derives from methodologically diverse studies in unimpaired, brain-lesioned, and mood-disordered populations. Relatively little of the work has been precisely replicated, and conclusions rest on parallel lines of evidence from diverse sources. The present level of knowledge suggests a model of emotional control based on interactive inhibition between a right negatively biased and left positively biased hemisphere. However, the details of such a model, including the precise conditions under which emotion-related functions are lateralized, and the mechanisms of such lateralization have yet to be elucidated.

Experimental measurements of sound velocity and attenuation constant in a mixture of air bubbles in fresh water, using a standing wave tube, are described. Bubble sizes in the mixtures were controlled between about 0.08- and 0.26-in. diameter, concentrations ranged from 0.03 to 1%, and applied frequencies from 60 to 20 000 cps. Bubbles in each mixture were of a single uniform size except for one series of experiments in which mixtures of bubbles of two discrete sizes were used. Attenuation constants were obtained for each mixture through a range of frequencies, including natural frequencies of the bubbles in the mixture. Velocity measurements were not obtained near the natural frequencies of the bubbles because high attenuation prevented the establishment of standing waves. Data obtained in the tubes were reduced to mean, infinite conditions and compared with available theory. The measurements show that theory gives at least a good estimate of both velocity and attenuation constant in the region investigated.

Summary We propose that discussions of benzodiazepines in the current psychiatric literature have become negatively biased and have strayed from the scientific evidence base. We advocate returning to the evidence in discussing benzodiazepines and adhering to clear definitions and conceptual rigour in commentary about them.

The great majority of residents appear to have decided whether or not to pursue a research career by the time they reached residency, and few of those with less than the highest research interest were enrolled in research tracks. Efforts to increase recruitment into research should center on identifying early developmental influences, eliminating barriers specific to women, and ensuring adequate funding to provide secure careers for talented potential researchers.