Functional asymmetry of the two cerebral hemispheres is a major characteristic of human brain organization and cognition. This phenomenon is also termed cerebral dominance, functional or brain lateralization, and hemispheric specialization. These terms all refer to the fact that the right and left hemispheres have different roles in mediating behavior and higher mental processes or cognition. In general terms, speech, language, and praxic (motor planning) skills are dependent on left hemisphere functioning, whereas spatial skills are dependent on right hemisphere processing. Functional asymmetry exists not only in adults, but also in young children and infants and, at least to some extent, in some nonhuman species.