Temporal and spatial frequencies interact in the contrast transfer function of the pattern electroretinogram

• Published in: Vision research (Oxford) 2007-07, Vol.47 (15), p.1992-1999
• Main Authors: Ben-Shlomo, G., Bach, M., Ofri, R.
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Check size; Contrast; Contrast Sensitivity - physiology; Contrast transfer characteristic; Electroretinography; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Humans; Linearity; Pattern ERG; Pattern Recognition, Visual - physiology; PERG; Photic Stimulation - methods; Retina - physiology; Temporal frequency; Vertebrates: nervous system and sense organs
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/j.visres.2007.04.009

The contrast transfer function (CTF) of the pattern electroretinogram (PERG) depends on temporal frequency. For transient stimulation it is fully linear; at faster stimulation rates it becomes strongly non-linear with an accelerated shape. In this study we investigated a range of stimulus parameters with the aim of studying the influence of temporal and spatial frequencies, as well as contrast levels, on the CTF; effects were quantified via an “index of linearity” IL. Both reversal rate and check size influenced linearity ( p < .001), examples: At a constant check size of 0.8°, 7.7 rps: IL = 1.0; 0.8°/24 rps: IL = 0.5; at a constant reversal rate of 19 rps, IL was 0.5 for 0.8°, but rose to 0.8 both for 0.2° and 18°. The reason for this complex response surface remains a puzzle, it cannot be explained by varying parvo/magnocellular contributions, and its possible influences on recordings in patients merit further studies.