Visual accommodation and target detection in the vicinity of a window post

J. Chong, T. J. Triggs

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


The visual environment of a driver in a car or a pilot in an airplane has intervening objects from the vehicle such as A-pillar posts between the windscreen and the doors in the car or cockpit pillars in the airplane. The presence of such objects can bias the observer's visual accommodation response because of the Mandelbaum effect (e.g., Owens, 1979). When subjects were allowed to focus toward a distance by looking through a large aperture in an intervening post, the detection (monocular) of a briefly presented distant target was found to be significantly better than when no aperture was present. When the size of the aperture was decreased from 2.3 to 1.15 deg diameter, target detection performance was significantly decreased and remained constant as further reduction of foveal cues was made. Although the detection results were generally in agreement with the visual accommodation results, detection accuracy changed significantly only with marked changes in accommodation. In addition to an accommodation bias, interference to target detection was also observed for those targets occurring at a laterally proximal position to the intervening object.

Original languageEnglish (US)
Pages (from-to)63-75
Number of pages13
JournalHuman Factors
Issue number1
StatePublished - 1989

ASJC Scopus subject areas

  • Human Factors and Ergonomics
  • Applied Psychology
  • Behavioral Neuroscience


Dive into the research topics of 'Visual accommodation and target detection in the vicinity of a window post'. Together they form a unique fingerprint.

Cite this