Douglas Jeske


This experiment was designed to determine the effects of vertically yoked prisms on standing center of balance (SCB). The BALANCE SYSTEM*tm [superscript] from Chattecx Corporation was utilized to quantify SCB under conditions of plano and 12 prism diopters yoked bases up or down. Test lenses were fitted over the habitual lens prescriptions of 35 young adult subjects with normal vision. Pressure sensitive transducers under the ball and heel of each foot provided data at a rate of 100 samples per second during two 10-second test periods, 0-10 s and 30-40 s after opening the eyes and fixating a muscle light at 5 metres. During each test period three variables related to SCB were computed: X, corresponding to leftward or rightward shifts; Y, corresponding to forward or rearward shifts; and D, the dispersion or variability in SCB. During three initial plano conditions, subjects showed no change in X, Y, or D values, thus providing evidence of test-retest reliability of the instrument. The X (left-right) value did not differ in any of the prism conditions. Bases down yoked prisms caused a rearward shift in SCB during both the 0-10 s (F=20.0, df=2, pADAPTIVE PSYCHOMETRIC PROCEDURE AVOIDS SPATIAL FREQUENCY DEPENDENT CHANGES IN DECISION CRITERIA


Year: 1992

Program Number: 2:45 pm

Author Affiliation: n/a

Co-Authors: Bradley Coffey

Co-Author Affiliation: n/a

Room: Scotland A