In our study two auditory oddball plus noise paradigms were used to generate EROs. One that required responding to the infrequently presented tone (active task, used in periadolescent and adult humans) and one that did not require any responses to the tones (passive task, used in rats and periadolescent humans). The use of passive tasks are important because they can be used in human participants who may be too young or have cognitive/behavioral challenges that preclude them from being able to adequately respond to the task requirements [41]. Secondly, passive tasks are important in animal research in circumstances where it is not possible to present the stimuli, and train the animal to respond to the stimuli, in a similar manner to humans without using food restriction/food rewards which presumably have different motivational concomitants.
