The role of design and training in artifact expertise : The case of mental abacus and visual attention

Previous accounts of how humans develop expertise have focused on how deliberate practice transforms the cognitive and perceptual representations and processes that give rise to expertise. However, the likelihood of developing expertise with a particular tool may also depend on the degree to which that tool fits pre-existing perceptual and cognitive abilities. The present studies explored whether the abacus – a modern descendent of the first human computing devices – evolved to exploit the constraints of human visual attention, or whether, instead, abacus expertise involves extending or adapting the capacity of human visual attention through practice. To address this question, we administered a series of visual search tasks to abacus experts and subjects who had little to no abacus experience, in which search targets and distractors were overlaid atop abacus “beads.” Across three studies, we found that experts and naïve subjects were faster to detect targets in semantically-relevant regions of the abacus, suggesting that the attentional biases that scaffold numerical processing in abacus experts require little to no experience with the abacus to develop, and may emerge from general properties of visual attention that are exploited by the design of the abacus itself.