Abstract
Braille is a haptic modality based on a system of raised dots to represent text. Analogously to eye movements in visual reading, braille readers move the reading hand(s) over the printed material to acquire text. In contrast to visual reading, bimanual braille reading raises the question of each hand’s contributing role, and the possibility of perceptual mechanisms distinct from visual reading. Here we analyzed the hand movement patterns of blind braille readers in order to examine the relationship between reading style, hand kinematics, and reading speed. Participants read standardized IReST text passages aloud while their hand movements were recorded with a specialized tracking system. Preliminary results suggest that reading styles strongly affected hand kinematics and performance. Participants who used a more independent hand movement style (e.g. scissors) completed trials faster on average than those who used more interdependent style (e.g. parallel or left marks). These styles were also characterized by lower intermanual correlation in kinematic markers such as regressive movements. In addition, we found that scissors-style readers were disproportionately likely to exhibit simultaneous disjoint reading, in which the two hands read different parts of the text in parallel. Notably, this suggests a neural “memory buffer” mechanism distinct from visual print or serial braille reading, as input acquired in parallel is sorted on the fly to reconstruct a serial text stream. Taken together, our results quantitatively support previous work suggesting that the ability to use independent hand movements may be an important factor in the development of efficient braille reading skills. While further research is needed to fully understand the mechanisms underlying these effects, our results provide new insights into the benefits of bimanual braille reading strategies and may have implications for the teaching of braille to blind individuals.