Hemispheric asymmetry in an artificial grammar task

In this experiment participants memorized letter strings, formed using a finite state grammar, and subsequently discriminated between new ''grammatical'' items and similar ''nongrammatical'' items. Test items were presented briefly in either the left or right visual field, and formed either from the same letter set as during training or a different set. Only when items were formed from the same letters as at study, and presented in the right visual filed, was discrimination performance better than chance. These results are consistent with the concept of an abstract visual form system that operates more effectively in the left hemisphere than in the right (Marsolek, 1995).