Effective scheduling of looking and talking during rapid automatized naming

Abstract

Rapid automatized naming (RAN) is strongly related to literacy gains in developing readers, reading disabilities, and reading ability in children and adults. Because successful RAN performance depends on the close coordination of a number of abilities, it is unclear what specific skills drive this RAN-reading relationship. The current study used concurrent recordings of young adult participants' vocalizations and eye movements during the RAN task to assess how individual variation in RAN performance depends on the coordination of visual and vocal processes. Results showed that fast RAN times are facilitated by having the eyes 1 or more items ahead of the current vocalization, as long as the eyes do not get so far ahead of the voice as to require a regressive eye movement to an earlier item. These data suggest that optimizing RAN performance is a problem of scheduling eye movements and vocalization given memory constraints and the efficiency of encoding and articulatory control. Both RAN completion time (conventionally used to indicate RAN performance) and eye-voice relations predicted some aspects of participants' eye movements on a separate sentence reading task. However, eye-voice relations predicted additional features of first-pass reading that were not predicted by RAN completion time. This shows that measurement of eye-voice patterns can identify important aspects of individual variation in reading that are not identified by the standard measure of RAN performance. We argue that RAN performance predicts reading ability because both tasks entail challenges of scheduling cognitive and linguistic processes that operate simultaneously on multiple linguistic inputs.

Figure 1

Average proportion of vocalization onsets with an eye-voice span (EVS) of 0, 1, or 2-or-more across RAN types.

Figure 2

Eye-voice traces for individual trials of the Letter RAN for three participants. The position in terms of RAN items (vertical axis) across time (horizontal axis) is shown with green lines for the eyes and blue lines for the voice. The insets provide a blow-up of the pattern for RAN items 10 through 18. EVS (measured in number of RAN items) is indicated by the magnitude of the vertical gap between the green and blue lines. Participant 15 (top panel) has a large average EVS; it can be seen that at the onset of vocalizing an item the eyes are almost always fixating on a RAN item that is one or two ahead. Participant 37 (middle panel) has a smaller average EVS and it is apparent that at times the voice catches up to the eyes, so that at the onset of vocalizing an item the eyes are fixating that same item. Participant 29 (bottom panel) often has a substantial lead of the eyes over the voice but has frequent regressive saccades that bring the eyes back to an earlier item.

Figure 3

Schematic timeline showing eye-voice relations across items during the RAN, as well as the memory requirements that are imposed when the eyes leave an item before articulation of the item begins. The top panel illustrates an EVS of one while the bottom panel illustrates an EVS of two. EVS is given by the difference in RAN items of the eyes and voice at the onset of vocalizing an item and is shown by the dashed vertical lines. An EVS of one (as in the top panel) occurs when at the onset of vocalizing an item (the left edge of the voice rectangle) the eyes are already fixating the next item; this relation between the eyes and the voice requires that a single RAN item be stored in memory (as indicated by the thought cloud). An EVS of two (as in the bottom panel) occurs when the eyes are already fixating two items ahead at the onset of vocalization; this relation between the eyes and the voice requires that two items must be stored in memory.