Phrase units as determinants of visual processing in music reading.

Keyboard musicians sight-read passages of music in which the amount of information about the presence of phrase units was systematically varied. A distinction was made between ‘physical’ unit markers, which allowed delineation of a unit prior to analysis of its component elements, and ‘structural’ unit markers, which defined a unit in terms of the sequential rules obeyed by its constituent elements. During the execution of the passages the text would be removed at a point known in advance only to the experimenter. Subjects were then required to execute all the material seen beyond this point to provide a measure of the eye-hand span at that point. It was found that the presence of structural markers increased span, and tended to cause span to extend exactly to a phrase boundary. The presence of physical markers did not increase span, although it also tended to cause span to extend exactly to a phrase boundary. The results suggest a clear analogy between the cognition of music and language, in that knowledge of abstract structure is of importance in the organization of immediate visual processing of text.