The closer the better: Hand proximity dynamically affects letter recognition accuracy

Abstract

A growing literature has suggested that processing of visual information presented near the hands is facilitated. In this study, we investigated whether the near-hands superiority effect also occurs with the hands moving. In two experiments, participants performed a cyclical bimanual movement task requiring concurrent visual identification of briefly presented letters. For both the static and dynamic hand conditions, the results showed improved letter recognition performance with the hands closer to the stimuli. The finding that the encoding advantage for near-hand stimuli also occurred with the hands moving suggests that the effect is regulated in real time, in accordance with the concept of a bimodal neural system that dynamically updates hand position in external space.

Fig. 1

A Side view of the experimental setup. B Front view of the experimental setup. C Top view of the experimental setup. The computer monitor was placed in a horizontal position above the moving-hands apparatus, which consisted of two moveable keypads (one for each hand) that could slide over a rail. The position of the keypads in the figure reflects the near hands condition (center–keypad distance 0 cm). The intermediate hands condition (center–keypad distance 17.5 cm) and far hands condition (center–keypad distance 35 cm) are indicated by arrows. Not drawn to scale

Fig. 2

Mean percentages of letters reported correctly from the three-letter arrays as a function of hand position in Experiment 1. Error bars are within-subjects standard errors of the means

Fig. 3

Mean percentages of (white) letters reported correctly from the six-letter arrays as a function of hand position in Experiment 2. Error bars are within-subjects standard errors of the means