Age-related changes in hemispheric organization
This chapter links recent behavioral and neuroimaging findings on hemispheric lateralization and aging to general ideas about hemispheric organization. The chapter has three main sections. The first section focuses on hemispheric organization. It reviews evidence concerning hemispheric specialization, at both anatomical and functional levels, and then describes three views of hemispheric interaction: insulation, inhibition, and cooperation. The second section describes two models concerning age-related changes in lateralization: the right hemiaging model and the age-related asymmetry reduction model. Evidence supporting each model is reviewed, and the two models are compared. The third section links the first two by considering how age-related asymmetry reductions relate to the three views of hemispheric interaction and models of hemispheric specialization.