[Abstract Title]. - Society for Neuroscience

Disclosures: A.K. Moschovakis , None; A.A. Kardamakis, None; A. Grantyn, None.
Poster
263. Eye Movements: Eye and Head Control
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 263.2/DD2
Topic: D.06.c. Eye and head control
Support: Dept. of Veterans Affairs Merit Award
Title: Laboratory measures of eye-head coupling predict spontaneous behavior in natural
environment
Authors: Z. C. THUMSER 1 , *J. S. STAHL 2,1 ;
1 Neurol., Cleveland Dept. of Veterans Affairs Med. Ctr., Cleveland, OH; 2 Dept Neurol, Case
Western Reserve Univ., Cleveland, OH
Abstract: The tendency to couple head movements to eye movements during gaze shifts varies
from person to person, and these “head movement tendencies” can be quantified in the
laboratory (Exp Brain Res 126(1999):41-54). It is unknown whether the laboratory measures
predict eye-head coupling during spontaneous viewing in a natural environment. We addressed
this question in 20 normal humans. Subjects were recorded in the laboratory making horizontal,
centrifugal saccades to a sequence of illuminated targets along a ±90° semicircular array, and
during an similar 30-minute period of spontaneous viewing while seated in an open park. Eye
movements were recorded using a lightweight head-mounted video oculography system. Head
movements were recorded indoors using an electromagnetic tracker and outdoors using a
geomagnetic heading sensor. Head movement tendencies in the laboratory were quantified by the
customary ocular motor range (COMR, the span of eye-in-head eccentricity in which the eyes
are customarily (probability 0.9) restricted), customary head orientation range (CHOR, the span
of head-on-neck range in which the head is customarily (probability 0.9) restricted), and eyeonly
range (EOR, the range of target eccentricities (with respect to the head) in which the gaze
shift is ordinarily (probability>0.5) made without a head movement). Head movement tendencies
in the outdoor environment were quantified by COMR, CHOR, and the Percentage of time in
which the Head was in Motion (HMoP). Indoor measures were based solely on the eye and head
positions following centrifugal saccades, whereas the outdoor measures were based on the entire
30-minute recording. The outdoor index HMoP correlated significantly with the indoor COMR
(r=-0.63), EOR (r=-0.55), and CHOR (r=+0.67), in each case indicating that stronger inlaboratory
head movement tendencies predicted that subjects spent more time with the head in
motion during spontaneous viewing. Indoor and outdoor CHOR were also significantly