Effect of a concurrent counting task on dynamic visual accommodation

• Published in: American journal of optometry and physiological optics Vol. 61; no. 9; pp. 590 - 594
• Main Authors: MALMSTROM, F. V, RANDLE, R. J
• Format: Journal Article
• Language: English
• Published: Baltimore, MD Williams & Wilkins 01.09.1984
• Subjects: Accommodation, Ocular; Adult; Arousal; Attention; Biological and medical sciences; Distance Perception; Dominance, Cerebral; Eye and associated structures. Visual pathways and centers. Vision; Fixation, Ocular; Form Perception; Fundamental and applied biological sciences. Psychology; Humans; Male; Motion Perception; Vertebrates: nervous system and sense organs; Human; Acquisition process; Accommodation; Vision
• ISSN: 0093-7002
• DOI: 10.1097/00006324-198409000-00009

The visual accommodation of four male subjects was selectively recorded over a 3-day period using an objective, continuously recording, infrared optometer to determine the effects of a concurrent counting task on their ability to accommodate to a sinusoidally changing focus stimulus ranging from 0.0 to 3.0 D. There was an increase in their steady-state errors in the direction of negative accommodation of from 0.25 to 0.50 D, but the magnitude of the steady-state error induced by the concurrent task did not change over the three sine wave frequencies used (0.1, 0.2 and 0.4 Hz). The results are discussed in terms of an accommodative "lag" model of sympathetic-parasympathetic arousal induced by superimposing an extraneous mental task.