• Optic nerve, tectal lobe, and midbrain tract lesions do not simply disturb spatial representation signals. These lesions also affect movement characteristics.

  • Optic nerve lesions change two-dimensional displacement and rotation at some spatial locations, while leaving response accuracy unaffected.

  • Tectal lobe lesions also change two-dimensional displacement and rotation, with the additional effect of attenuating turn amplitudes within the damaged visual hemifield.

  • Descending midbrain tract lesions alter the characteristics of movement variability in frontal responses. Responses achieving a given turn amplitude following this lesion look different than responses of similar amplitude prior to the lesion.


  • Conclusion:

    We need a new model.