Evidence for wide range of time scales in oculomotor plant dynamics: Implications for models of eye-movement control

• Published in: Vision research (Oxford) 2005-06, Vol.45 (12), p.1525-1542
• Main Authors: Sklavos, Sokratis, Porrill, John, Kaneko, Chris R.S., Dean, Paul
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - physiology; Adaptive control; Animals; Biological and medical sciences; Cerebellum; Cerebellum - physiology; Eye and associated structures. Visual pathways and centers. Vision; Eye movement; Eye Movements - physiology; Facial Muscles - physiology; Fundamental and applied biological sciences. Psychology; Macaca mulatta; Models, Animal; Motoneuron; Motor Neurons - physiology; Oculomotor; Principal Component Analysis - methods; Time Factors; Vertebrates: nervous system and sense organs
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/j.visres.2005.01.005

Oculomotor-plant dynamics are not well characterised, despite their importance for modelling eye-movement control. We analysed the time course of the globe’s return after horizontal displacements in three rhesus monkeys lightly anaesthetised with ketamine. The eye-position traces were well fitted by a sum of four exponentials (time constants 0.012, 0.099, 0.46, 7.8 s). The two long time-constant terms accounted for 25% of plant compliance, and led to a model that accounted for hitherto unexplained features of ocular motoneuron firing such as (i) hysteresis, and (ii) the inability of a 2 time-constant model to fit data for both fast and slow eye-movements.