To indicate their task choice, subjects responded with two response keys that differed from those assigned to perceptual decisions to avoid any carry-over effects.
In voluntary choice paradigms, for instance, each of the 2 tasks is usually mapped to one of the hands, meaning that participants indicate their task choice (intentions) by the hand they use to respond (actions).
For example, in the double registration procedure, participants make a separate response indicating their task choice prior to performing the chosen task (e.g., Arrington and Logan 2005; Millington et al. submitted for publication).
Twelve right-handed healthy adults performed the task of pointing with their arms, without vision, to indicate their subjective 'straight ahead', a task often used to assess the Egocentric Reference.
Before answering the choice tasks, participants had to indicate their most preferred level of each attribute.
However, in this experiment we asked subjects to complete the same different task right after indicating their answer on the number task.
Finally, the main task was the same as in Experiment 2. The subjects needed to do the number task on the basis of the direction of motion in the cued diagonal and to complete the same different task right after indicating their answer on the number task.
Subjects' attention on the visual stimulation was monitored in both conditions with a questionnaire about the content of the film, which indicated their full compliance with the task.
Further, no tenure information was visible when they completed the memory task or indicated their impressions.
During the gambling task, participants indicated their emotional response ("How do you feel about what just happened?") to the outcome of each gamble, using a linear rating scale.
In all tasks, players indicated their decision by pressing one of two buttons of an MRI-compatible response device held in the right hand (the left button was for diamond, rook, or check, depending on the task, and the right button for square, knight, no check).
