Hemisphere specialization, bilaterality, and sex dimorphism in noise resistance

This study shows the existence of right-sided lateral specialization of hemisphere noise resistance control of visual discrimination in rats. As a rule, right hemisphere activity, to a greater degree than left hemisphere activity is conducive to the improvement of noise resistance, the left hemisphere sometimes making it worse. Indications have been obtained concerning the existence of sex dimorphism of noise immunity in rats' visual discrimination. It is possible that the intact and split brain are more noise resistant in males than in females and are characterized by a greater asymmetry. The role of bilateral mechanisms in noise resistance is described: after section of the corpus callosum, noise resistance may either improve or deteriorate. It has been found that interhemispheric asymmetry can be changed up to its inversion by means of one of the hemisphere's polarization.