Comparison of angular frequency contrast sensitivity in young and older adults

Brazilian Journal of Medical and Biological Research

N.a. Santos²  M.l.b. Simas¹  R.m.t.b.l. Nogueira¹ 

[1] ,Universidade Federal da Paraíba Departamento de Psicologia Jõao Pessoa PB ,Brasil

关键词: Human aging;    Spatial frequency;    Angular frequency;    Contrast sensitivity;    Forced-choice method;   

DOI  :  10.1590/S0100-879X2004000300014

来源: SciELO

【 摘 要 】

The aim of the present study was to measure contrast sensitivity curves for angular frequencies in the range between 2 and 96 cycles/360º in older human adult volunteers and to compare these measurements with the more usual contrast sensitivity functions for sine-wave gratings. All subjects were free of identifiable ocular disease and had normal acuity. We measured the contrast thresholds for young adults (N = 6; age range, 20-26 years) and older adults (N = 6; age range, 60-67 years) using the psychophysical forced-choice method. In this paradigm the volunteers had to choose the stimulus containing a test frequency at low contrast (e.g., either a sine-wave grating or an angular frequency stimulus), or another neutral stimulus at mean luminance (without any contrast). Older adults presented a loss in contrast sensitivity at high and medium angular frequencies compared to the young adults (i.e., from 8 to 96 cycles/360º). Contrary to expectation, contrast sensitivity at low angular frequencies, i.e., 2 and 4 cycles/360º, was better for the older group than for the younger group. On the other hand, contrast sensitivity for sine-wave gratings at 3 and 4 cpd was higher for young adults as expected. These results suggest age-related changes in the contrast sensitivity function for angular frequencies.

【 授权许可】

CC BY   
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