Selecting a stimulus signal for linear systems analysis of the vestibulo-ocular reflex.
We evaluated 3 types of stimulus signals for use in estimating the transfer function of the vestibulo-ocular reflex. We used individual sine-wave, sum-of-sine, and pseudorandom stimuli. Five normal human subjects were tested 5 times each using each of the 3 stimulus types. Frequency domain techniques were used to estimate the transfer function at 0.01, 0.03, and 0.05 Hz. The most consistent estimates were obtained using individual sine-wave stimuli. The pseudorandom signal yielded the most variable estimates. A sum-of-sine stimulus composed of 3 sine-wave signals provided estimates slightly more variable than the individual sine-wave stimuli, but much less variable than the pseudorandom stimulus. The redundency of the sine and sum-of-sine stimuli seems to be an advantage by providing stable estimates of the transfer function in the presence of noise.
Engelken
E J
EJ
Aerospace Medicine Directorate, Armstrong Laboratory/AOCF, Brooks AFB, TX 78235.
Stevens
K W
KW
Enderle
J D
JD
D000328:Adult; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D009760:Nystagmus, Physiologic; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*