Abstract

Comparison of Cortical Activation during Subtraction in Mental Calculationb and with a Calculator

Yuki Murata, Hisaaki Tabuchi, Toshiaki Watanabe, Saiki Terasawa, Koki Nakajima, Toshie Kobayashi, Zhang Yong, Masao Okuhara, Keisuke Nakade, Suchinda Jarupat Maruo, Satomi Fujimori and Koji Terasawa

Several studies have shown that various types of cognitive processing exist and exert different effects on brain activity. However, when a subject performs the same task, whether the task involves processing or not, such as in mental calculation or with a calculator, the different influences on the brain remain unclear. The purpose of this study was to examine whether the influence of cortical activation when performing mental calculation and using a calculator have different effects on the brain. Fifteen healthy, right-handed participants (mean age, 26.3 ± 8.5 years; 12 men, 27.7 ± 9.0 years; 3 women, 20.6 ± 1.1 years) were recruited as subjects. We measured oxygenated hemoglobin (oxy-Hb) levels while subjects performed subtraction tasks by mental calculation or using a calculator (3 min each). Measurements were made at the frontal lobe and temporal lobe. In both lobes, oxy-Hb level was significantly increased during mental calculation. Locations showing significantly increased oxy-Hb in mental calculation were the prefrontal cortex in the frontal lobe and supramarginal gyrus in the temporal lobe. These results suggest that the brain responds differently to tasks in mental calculation and using a calculator. We hypothesized that using the electronic calculator needs fewer neural networks than performing mental calculation. In recent years, thanks to the development of machines, many tasks have been automated, making our lives easier and more convenient. Our results may provide one example that the developments of modern technology influence brain function.