def __init__(self,
                 rewardlogic,
                 focused = True,                               # whether this task is currently focused
                 markerbase = 1,                                # markers markerbase..markerbase+6 are used                       
                 event_interval=lambda: random.uniform(45,85),  # interval between two successive events
                 pic_off='light_off.png',                       # picture to display for the disabled light
                 pic_on='light_on.png',                         # picture to display for the enabled light
                 screen_offset=0,                               # offset to position this icon on one of the three screens
                 pic_params={'pos':[0,0],'scale':0.15},         # parameters for the picture() command
                 duration = 1.5,                                # duration for which the cue light stays on 
                 ):