Qualitative hemispheric differences for processing trigrams

The present study investigated qualitative hemispheric differences for processing trigrams by examining the nature of errors made when trigrams were directed to each visual field-hemisphere. Three types of trigrams, pronounceable letter trigrams, unpronounceable letter trigrams, and non-letter symbol trigrams, were presented. Recognition of each trigram type resulted in significant visual field differences in error types. Pronounceable vs. unpronounceable letter trigrams yielded similar visual field differences in error types, whereas letter vs. non-letter symbol trigrams yielded opposite patterns of visual field differences in error types. These results suggest that hemispheric mode of trigram processing changes as a function of letter vs. non-letter type, but not as a function of pronounceability per se. Moreover, the direction of this change is opposite for the two hemispheres.