Eye Movement in Music Reading - Refixation

Refixation

A refixation is a fixation on information that has already been fixated on during the same reading. In the reading of two-stave keyboard music, there are two forms of refixation: (1) up or down within a chord, after the chord has already been inspected on both staves (vertical refixation), and (2) leftward refixation to a previous chord (either back horizontally on the same stave or diagonally to the other stave). These are analogous to Pollatsek & Rayner’s two categories of refixation in the reading of language: (1) “same-word rightward refixation”, i.e., on different syllables in the same word, and (2) “leftward refixation” to previously read words (also known as “regression”).

Leftward refixation occurs in music reading at all skill-levels. It involves a saccade back to the previous note/chord (occasionally even back two notes/chords), followed by at least one returning saccade to the right, to regain lost ground. Weaver reported that leftward regressions run from 7% to a substantial 23% of all saccades in the sight-reading of keyboard music. Goolsby and Smith reported significant levels of leftward refixation across all skill-levels in the sight-reading of melodies.

Looking at the same information more than once is, prima facie, a costly behaviour that must be weighed against the need to keep pace with the tempo of the music. Leftward refixation involves a greater investment of time than vertical refixation, and on logical grounds is likely to be considerably less common. For the same reason, the rates of both forms of refixation are likely to be sensitive to tempo, with lower rates at faster speed to meet the demand for making swifter progress across the score. Souter confirmed both of these suppositions in the skilled sight-reading of keyboard music. He found that at slow tempo (one chord a second), 23.13% (SD 5.76%) of saccades were involved in vertical refixation compared with 5.05% (4.81%) in leftward refixation (p < 0.001). At fast tempo (two chords a second), the rates were 8.15% (SD 4.41%) for vertical refixation compared with 2.41% (2.37%) for leftward refixation (p = 0.011). These significant differences occurred even though recovery saccades were included in the counts for leftward refixations, effectively doubling their number. The reductions in the rate of vertical refixation upon the doubling of tempo was highly significant (p < 0.001), but for leftward refixation was not (p = 0.209), possibly because of the low baseline.