In conclusion, it is obvious from both the optic nerve and tectal lobe studies that the current model needs revising in order to account for results it predicted would not exist. One of the more interesting and difficult things to account for is how and why behavior is effected when a tectal lobe is removed after an optic nerve lesion, even though sensory input is not further effected. Possible answers for this dilemma are that the tectum produces some sort of default signal, even in the absence of sensory input, that produces an ipsilateral bias after the tectal lobe is removed. Another aspect that is missing from the model that has physiological backing is that of communication between the tectal lobes. It has been shown that there are physical connections between the lobes, especially those governing binocular vision, that could in part be responsible for the bias. Whatever the case may be, it is now clear that optic nerve sections and tectal lobe removals do not produce the same deficit and that there is need to study the optic tectum in greater depth.