Contrast sensitivity loss with aging: sampling efficiency and equivalent noise at different spatial frequencies

Pardhan, Shahina (2004) Contrast sensitivity loss with aging: sampling efficiency and equivalent noise at different spatial frequencies. Journal of the Optical Society of America A. ISSN 1084-7529

Full text not available from this repository.

Abstract

The relative contributions of optical and neural factors to the decrease in visual function with aging were investigated by measurement of contrast detection at three different spatial frequencies, in the presence of external noise, on young and older subjects. Contrast detection in noise functions allows two parameters to be measured: sampling efficiency, which indicates neural changes, and equivalent noise, which demonstrates optical effects. Contrast thresholds were measured in the presence of four levels (including zero) of externally added visual noise. Measurements were obtained from eight young and eight older visually normal observers. Compared with young subjects, older subjects showed significantly (p < 0.05) lower sampling efficiencies at spatial frequencies of 1 and 4 cycles per degree (c/deg) and significantly higher equivalent noise levels for gratings of 10 c/deg. Neural and optical factors affect contrast sensitivity loss with aging differently, depending on the spatial frequency tested, implying the existence of different mechanisms.

Item Type: Journal Article
Additional Information: Citation: Pardhan, S., 2004. Contrast sensitivity loss with aging: sampling efficiency and equivalent noise at different spatial frequencies. Journal of the Optical Society of America A, 21(2), pp.169-175..
Faculty: Faculty of Science & Technology
Depositing User: Mr I Walker
Date Deposited: 02 Nov 2010 14:09
Last Modified: 07 Jul 2016 12:48
URI: http://arro.anglia.ac.uk/id/eprint/114370

Actions (login required)

Edit Item Edit Item