Schematic of the parametric demand selection task, (a) Example trials of
the categorization task with a digit printed on a colored circle. The color cued
which task to perform. The response mappings shown below the digits are for the
reader’s reference and did not actually appear on the screen, (b) An
example of six deck cues with their associated effort level pairing, based on
the probability of task switching in 13 trials from that deck, (c) Schematic of
block events during the Learning Phase. First, a symbol icon is presented for 1
sec, after which the participant completes 13 categorization trials with the
associated cue tiled on the background, (d) Schematic of block events during the
Test Phase. In the “Selection” epoch, the participant chooses
between two symbol icons that are associated with two different effort levels,
with a deadline of 3 sec. In the “Execution” epoch, the
participant executes the effort level associated with the selected option, while
the selected cue is tiled on the background.