City Research Online

Abstract

While the contrast sensitivity function (CSF) changes markedly during infancy, there is no consensus regarding whether, how, and why it continues to develop in later childhood. Here we analyzed previously published data (N = 1,928 CSFs), and present new psychophysical findings from 98 children (4.7–14.8 years) and 50 adults (18.1–29.7 years), in order to establish: (1) Does the CSF change during childhood? (2) How large is the developmental effect size? (3) Are any changes uniform across the CSF, or frequency-specific? (4) Can some or all of the changes be explained by ‘non-visual’ (i.e., procedural/cognitive) factors, such as boredom or inattentiveness? The new data were collected using a four-alternative forced-choice [4AFC] Gabor-detection task, with two different psychophysical procedures (Weighted Staircase; QUEST+), and suprathreshold (false-negative) catch trials to quantify lapse rates. It is shown that from 4—18 years, the CSF improves (at an exponentially decaying rate) by approximately 0.3 log10 units (a doubling of CS), with 90% of this change complete by 12 years. The size of the effect was small relative to individual variability, with age alone explaining less than one sixth of variability (16%), and most children performing as well as some adults (i.e., falling within the 90% population limits for adults). Development was frequency-specific, with changes occurring primarily around or below the CSF peak (≤ 4 cpd). At least half --- and potentially all --- of the changes observed could be explained by ‘non-visual’ factors (e.g., lapses in concentration), though possible biological mechanisms are discussed.

Publication Type:	Article
Additional Information:	Copyright 2020 The Authors. This work is licensed under a Creative Commons Attribution 4.0 International License.
Publisher Keywords:	Children, Development, Contrast Sensitivity, Contrast Sensitivity Function, Psychophysics, QUEST+, Staircase, Gabor, Four Alternative Forced Choice
Subjects:	R Medicine > RE Ophthalmology
Departments:	School of Health & Psychological Sciences > Optometry & Visual Sciences
SWORD Depositor:	Symplectic Administrator

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