Mouse_response items work analogously to the keyboard_response items, with the difference that mouse clicks are recorded. There are 5 types of mouse clicks, which can be used as Correct response or Allowed responses. For more information, see the keyboard_response item.
left_button / 1
middle_button / 2
right_button / 3
scroll_up / 4
scroll_down / 5
For more information, please refer to the help page of the keyboard_response item.