Journal of Taiwan Occupational Therapy Research and Practice
An experiment was conducted to evaluate the effect of order of reporting stimulus dimension in multidimensional stimulus identification using switch task paradigm. Eight healthy participants were required to identify each two-dimensional symbol by pushing the corresponding buttons on the keypad on which there were two columns representing the two dimensions, color and shape. The two orders of report were Order Color/Shape and Order Shape/Color. There was a task cue prior to each presentation of a symbol indicating the particular report order the participants should perform. The cue changed randomly. Both behavioral data and event-related potentials were collected. Analysis of variance showed that order of report had a significant effect on response time for the first dimension. Response time for the first dimension for Order Color/Shape was significantly longer than Order Shape/Color. Response time for the second dimension for Order Color/Shape was shorter than Order Shape/Color but was not statistically significant. Analysis of behavioral data showed switch cost indicated by increase in response time was greater for Order Shape/Color, a less appropriate order of reporting dimensional values, than Order Color/Shape. Neural activities under Order Color/Shape and Order Shape/Color were different, and it seems plausible that participants showed more N2 inhibition for Order Shape/Color than for Order Color/Shape which fits the Chinese adjective-then-noun language habit.