WAVE LABORATORY

Wright State University's Aerospace and Virtual Environments Laboratory

The Opto-kinetic Cervical Reflex (OKCR)

Introduction

The attitude indicator was designed based on the assumption that the axis of the head remains stable with the axis of the aircraft. However, research shows that pilots tilt (roll) their heads to keep the horizon stationary on their fovea during aircraft banks. This reflex, referred to as  the opto-kinetic cervical reflex (OKCR) improves spatial awareness by establishing the horizon retinal image as a stabilized primary visual-spatial cue. Enhance figure 1 below.

Figure 1. The opto-kinetic Cervical Reflex

Results

Results from three studies conducted at WSU in non-moving simulators (Patterson and Smith) and an F-15 (Merryman) that show the OKCR.

Figure 2. The OKCR for three studies at WSU.

Summary

• Pilots reflexively tilt heads toward horizon during VMC roll maneuvers.
• Head movement acts to stabilize retinal image.
• Generated by motion on retina, not vestibular.
• Stabilized horizon is the primary visual cue.
• Peripherally viewed cockpit structures secondary cues.
• Secondary cues move with airframe.
• Control movement compatible with secondary cues.
• Beyond 40 degrees decrease in head displacement, so pilots can not stabilize the horizon.
• Horizon acceleration, stabilization of secondary cues.
• Sudden switch may lead to false perceptions.
• When transitioning from visual to instruments:
      - motion reversal b/w outside and inside visual cues.
      - control display incompatibility need to switch cognitive model.

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Copyright 2000, All rights reserved by Jennie J. Gallimore, Ph.D.
Wright State University, Dayton OH
For problems or questions regarding this page contact Jennie J. Gallimore, Ph.D.
08/08/00