Citation

Salassa JR, Zapala DA. Wilderness Environ. Med. 2009; 20(4): 378-382.

Affiliation

Department of Otorhinolaryngology/Head and Neck Surgery, Mayo Clinic Florida, 4500 San Pablo Rd, Jacksonville, FL 32224, USA. salassa.john@mayo.edu

Copyright

(Copyright © 2009, Elsevier Publishing)

DOI

10.1580/1080-6032-020.004.0378

PMID

20030449

Abstract

Individual psychological responses to heights vary on a continuum from acrophobia to height intolerance, height tolerance, and height enjoyment. This paper reviews the English literature and summarizes the physiologic and psychological factors that generate different responses to heights while standing still in a static or motionless environment. Perceptual cues to height arise from vision. Normal postural sway of 2 cm for peripheral objects within 3 m increases as eye-object distance increases. Postural sway >10 cm can result in a fall. A minimum of 20 minutes of peripheral retinal arc is required to detect motion. Trigonometry dictates that a 20-minute peripheral retinal arch can no longer be achieved in a standing position at an eye-object distance of >20 m. At this distance, visual cues conflict with somatosensory and vestibular inputs, resulting in variable degrees of imbalance. Co-occurring deficits in the visual, vestibular, and somatosensory systems can significantly increase height imbalance. An individual's psychological makeup, influenced by learned and genetic factors, can influence reactions to height imbalance. Enhancing peripheral vision and vestibular, proprioceptive, and haptic functions may improve height imbalance. Psychotherapy may improve the troubling subjective sensations to heights.

Language: en