Affiliations: Department of Otolaryngology Head and Neck Surgery,
Johns Hopkins School of Medicine, Baltimore, MD, USA | Departments of Neurology, Neuroscience, and Biomedical
Engineering, Johns Hopkins School of Medicine, Baltimore, MD, USA
Note: [] Corresponding author: Michael C. Schubert PT, PhD, Department of
Otolaryngology Head and Neck Surgery, Johns Hopkins School of Medicine, 601 N.
Caroline St, JHOC Rm 6245, Baltimore, MD 21287-0910, USA. Tel.: +1 410 955
9567; Fax: +1 410 955 6526; E-mail: [email protected]
Abstract: Purpose: This paper focuses on motor learning within the saccadic
and vestibulo-ocular reflex (VOR) oculomotor systems, vital for our
understanding how the brain keeps these subsystems calibrated in the presence
of disease, trauma, and the changes that invariably accompany normal
development and aging. We will concentrate on new information related to
multiple time scales of saccade motor learning, adaptation of the VOR during
high-velocity impulses, and the role of saccades in VOR adaptation. The role of
the cerebellum in both systems is considered. Methods: Review of data involving saccade and VOR motor learning. Results: Data supports learning
within the saccadic and VOR oculomotor systems is influenced by 1). Multiple
time scales, with different rates of both learning and forgetting (seconds,
minutes, hours, days, and months). In the case of forgetting, relearning on a
similar task may be faster. 2). Pattern of training, learning and forgetting
are not similarly achieved. Different contexts require different motor
behaviors and rest periods between training sessions can be important for
memory consolidation. Conclusions: The central nervous system has the
difficult task of determining where blame resides when motor performance is
impaired (the credit assignment problem). Saccade and VOR motor learning takes
place at multiple levels within the nervous system, from alterations in ion
channel and membrane properties on single neurons, to more complex changes in
neural circuit behavior and higher-level cognitive processes including
prediction.
