THRESHOLD OF STIMULATION OF THE HORIZONTAL SEMICIRCULAR CANALS IN MAN WITH PARTICULAR REFERENCE TO THE SIGNIFICANCE OF THE FIRST DERIVATIVE OF ANGULAR ACCELERATION AS A STIMULUS.
Abstract
By use of the human centrifuge, records of responses both to constant angular acceleration and to changes in angular acceleration were obtained. The indicator was the oculo-gyral illusion, and three types of responses were obtained: left movement, no movement, and right movement. The responses were made at 20-second intervals and were related to the mean angular acceleration calculated for the preceding 20-second period. The mean change between four 20second periods (80-second) were used. Fairly consistent relationships between the direction and amount of change in acceleration, as expressed in each of the three types of response were obtained. A threshold for change (mean change between four 20-second periods) in both positive and negative angular acceleration was determined to be about 0.12 degrees/sec/sec. It was also found that the reliability of response to constant acceleration decreased as the length of the period to which response referred increased beyond 20 seconds at near-threshold rates. It is possible to obtain a threshold for the effectiveness of the fi9st derivative of acceleration, or the change in the rate of change in velocity. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 12, 1947
- Accession Number
- AD0467971
Entities
People
- Ashton Graybiel
- Bruce V. Leamer
- D. I. Hupp
- S. Howard Bartley
- W. A. Kerr
Organizations
- Naval Aerospace Medical Institute