Comparison of angular frequency contrast sensitivity in young and older adults

• Published in: Brazilian journal of medical and biological research 2004-03, Vol.37 (3), p.375-378
• Main Authors: Santos, N A, Simas, M L B, Nogueira, R M T B L
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Angular frequency; BIOLOGY; Contrast sensitivity; Contrast Sensitivity - physiology; Forced-choice method; Human aging; Humans; MEDICINE, RESEARCH & EXPERIMENTAL; Middle Aged; Photic Stimulation - methods; Sensory Thresholds; Spatial frequency; Visual Perception - physiology
• ISSN: 0100-879X; 1414-431X; 0100-879X; 1414-431X
• DOI: 10.1590/S0100-879X2004000300014

The aim of the present study was to measure contrast sensitivity curves for angular frequencies in the range between 2 and 96 cycles/360 masculine 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/360 degrees). Contrary to expectation, contrast sensitivity at low angular frequencies, i.e., 2 and 4 cycles/360 degrees, 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.