Figure 2

Example trial stimulus sequence and timing. Example trial stimulus sequence and timing diagram. In this example, the participant would enter the IC state during intervals 2) and 3) - to select responses A and B - and would remain in the NC state at all other times. The task cue at the bottom of the display indicates that this is a mental arithmetic trial. Note that at the end of each trial, when participants were asked to explicitly verify which answer(s) they selected, they also gave a rating, on a scale of 1-5, of how engaged they felt they were in the task during the trial. These data were used for verification purposes only and were not used in the quantitative analysis.