Brain activation during abacus-based mental calculation with fMRI: a comparison between abacus experts and normal subjects

The question of the neural bases of computation processing is a highly debated topic and from a functional point of view, solving computation-based problems is a complex cognitive skill requiring numbers to be held and manipulated on a short-term representational medium while the dedicated resolution algorithm is applied. This study used a 3T fMRI system with BOLD contrast sequences to explore the brain activation differences between the abacus-based experts and the normal subjects through three designed problem paradigms: the covert reading, one-digit and two-digit contiguous additions. All the acquired data were analyzed by using SPM99 software and a MNI template. From the study results, several basic and complex cognitive processes observed in the two groups were fairly consistent, because they all required numerical numbers to be held and manipulated through visual imagery procedures while applying their individual resolution algorithm. However, in the abacus experts, one unique area was observed at nucleus (putamen) area, suggesting control of voluntary movement in cognitive process was involved in mental computation. And also, after a long time training and practice, the experts might modify (or buildup) their cognitive processes involving in computations through a more effective calculation network. They tended to use simple memory retrieval procedure to deal with certain parts of complex processes in mental computations, by performing all the computation steps through finger-manipulating the abacus beads (in control of voluntary movement) from a virtual abacus (a traditional Chinese calculator).