The visual control of locomotion is based on the detection of Optical flow patterns produced at a moving point of observation. This project would continue research on the perception of heading from optical flow and extend this research by examining the functional significance of optical flow for the control of gait and posture during walking. One set of perceptual experiments will address outstanding questions regarding: (1) the effects of surface texture, shading, 3D structure, and flow field noise on the perception of heading, (2) the importance of specific flow field variables for perception of translational and curvilinear heading, and (3) the decomposition of eye rotation during translation and during curvilinear movement. A second set of perceptual-motor experiments will attempt to map out directionally-specific, phase-dependent control relations between optical flow variables and the motor parameters of gait and posture. Subject will view large-field optical flow displays projected in a hemispherical dome during treadmill walking, while their gait kinematics and dynamics are monitored. The control relations will be tested using four types of manipulations: (1) sudden perturbations of the optical flow field that induce adjustments in gait, (2) continuous oscillations in the flow field that induce postural sway during walking, (3) qualitative changes from one class of optical flow patterns to another, e.g. translational to curvilinear movement, and (4) rearrangement of the relationship between the optical flow pattern and the gait effectors. The results will contribute to basic knowledge about the visual control of locomotion, and will provide a basis for understanding perceptual-motor and gait disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG005223-08
Application #
3115797
Study Section
Visual Sciences B Study Section (VISB)
Project Start
1985-06-01
Project End
1994-08-31
Budget Start
1993-09-15
Budget End
1994-08-31
Support Year
8
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Brown University
Department
Type
Schools of Arts and Sciences
DUNS #
001785542
City
Providence
State
RI
Country
United States
Zip Code
02912
Bardy, B G; Warren Jr, W H; Kay, B A (1996) Motion parallax is used to control postural sway during walking. Exp Brain Res 111:271-82
Goldfield, E C; Kay, B A; Warren Jr, W H (1993) Infant bouncing: the assembly and tuning of action systems. Child Dev 64:1128-42
Warren, W H; Kurtz, K J (1992) The role of central and peripheral vision in perceiving the direction of self-motion. Percept Psychophys 51:443-54
Warren Jr, W H; Blackwell, A W; Kurtz, K J et al. (1991) On the sufficiency of the velocity field for perception of heading. Biol Cybern 65:311-20
Warren Jr, W H; Mestre, D R; Blackwell, A W et al. (1991) Perception of circular heading from optical flow. J Exp Psychol Hum Percept Perform 17:28-43
Warren Jr, W H; Hannon, D J (1990) Eye movements and optical flow. J Opt Soc Am A 7:160-9
Warren Jr, W H; Blackwell, A W; Morris, M W (1989) Age differences in perceiving the direction of self-motion from optical flow. J Gerontol 44:P147-53
Warren Jr, W H; Morris, M W; Kalish, M (1988) Perception of translational heading from optical flow. J Exp Psychol Hum Percept Perform 14:646-60