Validation of the lateral limits technique with a callosotomy patient

The lateral limits technique, presented by Myers and Sperry, was evaluated with a right-handed callosotomy patient. Consistent with traditional tachistoscopic findings, right visual-field presentations were superior for naming of letters and pictures, as well as rhyming. Left field presentations were superior for line orientation. Determination of the testing fields was insufficiently precise when the blind spot was used as a reference. An eye asymmetry was observed in both location of lateral limits and visual acuity. However, complete lateralization of input without interhemispheric transfer was achieved when presentation was made to fields of equal acuity. We conclude that the technique is valid and valuable for prolonged unilateral stimulation, but that care must be taken in determining appropriate and comparable testing fields.