title: Microstimulation of the midbrain tegmentum creates learning signals for saccade adaptation.
abstract: Error signals are vital to motor learning. However, we know little about pathways that transmit error signals for learning in voluntary movements. Here we show that microstimulation of the midbrain tegmentum can induce learning in saccadic eye movements in monkeys. Weak electrical stimuli delivered approximately 200 ms after saccades in one horizontal direction produced gradual and marked changes in saccade gain. The spatial and temporal characteristics of the produced changes were similar to those of adaptation induced by real visual error. When stimulation was applied after saccades in two different directions, endpoints of these saccades gradually shifted in the same direction in two dimensions. We conclude that microstimulation created powerful learning signals that dictate the direction of adaptive shift in movement endpoints. Our findings suggest that the error signals for saccade adaptation are conveyed in a pathway that courses through the midbrain tegmentum.
authors.affiliation: Department of Neurophysiology, Doctoral Program in Kansei Behavioral and Brain Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8574, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kojima
authors.forename: Kaoru
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D004558:Electric Stimulation / Q000379:methods; D007858:Learning / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D012438:Saccades / Q000502:physiology*; D013681:Tegmentum Mesencephali / Q000502:physiology