DISCONJUGATE MEMORY-GUIDED SACCADES TO DISPARATE TARGETS - EVIDENCE FOR 3D SENSITIVITY

The saccadic system has been traditionally regarded as two-dimensional (horizontal, vertical) and basically conjugate in the two eyes. Howev er, saccades to disparate targets (e.g., targets in real three-dimensi onal space that are located in different directions and at different d istances) are naturally disconjugate, We report here that memory-guide d saccades to a disparate target flashed 1 s earlier become disconjuga te following repeated trials. After 15 min of repetition, the disconju gacy persists even when the target to be remembered is no longer dispa rate. This suggests fast memory-based learning. Learning, however, fai ls to occur if, during the repetition trials, the memory delay is 2 s. These findings suggest that the saccadic system has access to a 3D re presentation of targets and is gifted with 3D short-term memory and le arning capacity.