Finger movements in braille reading: the effect of local ambiguity.

The hand movements of blind readers were recorded while they read sentences containing temporary local ambiguities, designed to induce garden path effects upon disambiguation. A syntactically ambiguous beginning ("The spy saw the cop with ... ") was compatible with attachment of the following prepositional phrase (PP) either to the verb ("saw") or the noun ("cop"), but the content of the PP was inconsistent with verb phrase attachment in NPA sentences ("with a revolver"), not in VPA sentences ("with binoculars"). Mean total scanning time per character increased in the PP region of NPA sentences, not of VPA sentences. The effect, however, depended on both the content of the PP and its predictability, and was significant by items only when both factors favoured VPA. The slowing down over the PP was entirely due to increased incidence of regressions to that region, and first-pass scanning speed was unaffected by sentence type. In studies with visual reading, disambiguation has been found to have a large effect on first-pass scanning. The results confirm previous suggestions that regressions are the main repair device available to the braille reader to cope with local increases in processing load.