Lateralization of frontal lobe functions and cognitive novelty.

The two hemispheres are functionally different in ways not adequately captured by the classic distinction between linguistic and nonlinguistic processes. The right hemisphere is critical for processing novel cognitive situations. The left hemisphere is key to the processes mediated by well-routinized representations and strategies. The left frontal systems appear to be critical for the cognitive selection driven by the content of working memory and for context-dependent behavior, the right frontal systems for cognitive selection driven by the external environment and for context-independent behavior. The crucial role of the right hemisphere in processing cognitively novel situations underscores the importance of the right frontal systems in task orientation and in the assembly of novel cognitive strategies.