title: Effects of visual environment on quiet standing by young and old adults.
abstract: The authors manipulated the circumstances in which individuals are typically embedded when standing upright by manipulating the intensity of light and the stationary structure of the environment. They expected that the manipulations would affect 12 older participants (aged 65-82 years) more than it would 12 younger participants (aged 22-24 years). Linear (e.g., total path length) and nonlinear (e.g., maximum line length of recurrent points in phase space) measures of the center of pressure time series confirmed that expectation. Moreover, for some measures, there was a suggestion that participants' visual contrast sensitivity (an index of neurophysiological age) was a more important contributing factor overall than was their chronological age. In the Discussion, the authors highlight the significance of interactive effects of environmental, organismic, and task constraints on quiet standing.
authors.affiliation: Department of Physical Therapy, University of Connecticut, 358 Mansfield Road, Unit 2101, Storrs, 06269-2101, USA. jeffrey.kinsella-shaw@uconn.edu
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Kinsella-Shaw
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Harrison
authors.forename: Cristina
authors.initials: C
authors.lastname: Colon-Semenza
authors.forename: Michael T
authors.initials: MT
authors.lastname: Turvey
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015350:Contrast Sensitivity / Q000502:physiology*; D004777:Environment; D006801:Humans; D008029:Lighting; D008954:Models, Biological; D010775:Photic Stimulation; D011187:Posture / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012016:Reference Values