Event-related potential as a measure of effects of report order and training on identification of multidimensional stimuli

This experiment investigated effects of report order and training on multidimensional stimulus identification. Subjects were required to identify each two-dimensional symbol. There were two orders of reporting the two dimensions of a stimulus. Subjects performed the task for three practice sessions. Both behavioral data and event-related potentials were recorded. Analysis showed order of report had no significant effect on behavior data. But when participants responded in Order Shape/Part, they showed more N2 inhibition for Order Part/Shape. The P3 mean amplitude was marginally significantly greater for Order Part/Shape than Order Shape/Part. This indicated Order Part/Shape, according to natural language habits, was more appropriate and less cognitively demanding than Order Shape/Part. For the two report orders, along with reduction of reaction time, amplitude of N1 and N2 increased with practice. Amplitude of P2 decreased with practice, and no P3 habituation was found. ERP data indicated no habituation effect. Results suggested neural activity depended not only on perceptual mechanism but also on extent of learning.