High resolution event-related potentials analysis of the arithmetic-operation effect in mental arithmetic

Early, late and slow waves of event-related potentials (erps) appearing around 0-300 ms, 300-500 ms and after 500 ms respectively post-question presentation have been differentially associated to mental arithmetic processing (MAP). We hypothesized that arithmetic-operation effect (AOE) will show greater modulation of early components (P100, P200) in high-frequency erps; late components (P300, N300) and slow waves in low-frequency ERP when large-size problems are employed.

Fourteen normal human subjects mentally processed large- and small-size addition, division, multiplication and subtraction problems. Spatiotemporal differences between these arithmetic-operations were studied by way of comparing amplitudes and latencies of early, late and slow waves.

All components were modulated by AOE. Modulated was observed as early as 100 ms post-question presentation (in high-frequency ERP components). AOE was very pronounced in large-size problems (in low-frequency ERP components).

Results suggest that modulation by AOE of ERP components is improved when large-size problems and low-frequency ERP components are employed. Thus, differentiation of neuropsychological processes manifested by amplitude and latency of ERP components may be best studied by first separating components into high- and low-frequency erps.

Findings raise the potential of obtaining ERP indices that may improve findings about the degree (and time) of engagement of cognitive processes (e.g. Strategy employed in MAP).