Mixed vs. BlockedExperiment 3: Mixed vs Blocked; Dashboard Paradigm

In this condition, participants are allowed to choose which task to perform on each trial. At the beginning of each trial, the message "Choose your task" appears in the center of the screen. Participants choose one of four tasks by clicking on the corresponding button on the left side of the patch. The button is deactivated when the number of trials completed in a task reached 50. If a deactivated button is clicked, the message "Choose another task" appears at the center again.

In this condition, participants begin by choosing one of the four tasks. Participants do not need to choose a task before each trial; the current trial is drawn automatically from the most recently chosen task until the participant actively chooses to switch tasks or until the full complement of trials for that task is exhausted. At the start of each trial, a "switch" button appears at the center of the display for 700 msec. If participants click on that button within the 700 msec, they are prompted to select the task. If participants does not click the switch button within the 700 msec window, the button vanished and a trial from the current task will be presented. When the number of trials of one task reaches its limit, participants are asked to select another task.

In this condition, participants do not choose which task to perform on each trial. The order of the trials is randomized and assigned to the participant before each trial. Before each trial, the target task is highlighted and activated, while the other buttons remain deactivated. The trial begins only when the participant clicks on the correct task button.

In this condition, participants also have no choice. Here, trials of each task type are presented in a blocked fashion. After 50 trials of one type, the task is changed to another task. To keep the motor demands similar to the choice conditions, at the beginning of each trial, participants need to click the highlighted button for the assigned task type. The order of blocks is counterbalanced across participants.

Participants in this condition see trials in the order chosen by a participant in the Trial Choice condition. Again, to keep the motor demands similar to the choice conditions, at the beginning of each trial, participants need to click the highlighted task button for the assigned task type though they have no choice in the matter.

The observer gets to make a choice about the sequence of trials they see

The search tasks are either intermixed. Otherwise trials are run in blocks