Data Interpretations

As it has turned out so far, preliminary data is proving all of our predictions to be wrong. The prediction that optic nerve lesions would lead to no change in behavior other than an ipsilateral monocular field deficit has given way to an observed bias in the frogs to displace to the contralateral side of the lesion and to jump shorter distances. For a more in depth look at the optic nerve lesion visit Maushumi Mavinku, in the meantime you can see a comparison between the behavior of two different pre-lesion frogs and their post-optic nerve lesion behavior.

Green frog had a left optic nerve lesion, and thus a deficit field in the left monocular field. The graphs consist of a green crosshair for the frog's initial positon, a red dot for the stimulus position(the stimulus being a mealworm), and blue lines representing where the frog displaced and where it's mid-saggital plane was lined up. The dotted lines are called prey lines and connect the initial position of the frog to the stimulus position. Note that there is a very strong tendency for the frog to displace to the right of the prey line.Green frog.

Brown frog had a right optic nerve section and exhibited the same biases as Green frog, but in the contralateral fields. Brown frog's bias does not appear to be as strong, but the frog was later found to have a broken leg and so it is difficult to tell how much of an effect the injury had on it's orienting behavior. Brown frog.

Both frogs then underwent tectal lobe lesions contralateral to their optic nerve lesions, with the prediction that the behavior would not be further altered as result of the new tectal lobe lesion, even though the optic nerve data was not what was originally anticipated. Brown frog became unresponsive and no data was collected, but Green frog was responsive and showed a large change in behavior. An increased biased to displace right was obeserved even though sensory input had not changed and was still limited to input from the right optic nerve. In addition to the increased displacement bias there was also evidence for a rightward bias in the frog’s ability to accurately line up with the stimulus. Instead of looking at the stimulus directly, the frog's line of sight was always to the right of the target.

Conclusion

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This page was last updated on August 7th, 1998
and is maintained by Zach Hettinger.