Immature visual neural system in children reflected by contrast sensitivity with adaptive optics correction

Abstract

This study aimed to explore the neural development status of the visual system of children (around 8 years old) using contrast sensitivity. We achieved this by eliminating the influence of higher order aberrations (HOAs) with adaptive optics correction. We measured HOAs, modulation transfer functions (MTFs) and contrast sensitivity functions (CSFs) of six children and five adults with both corrected and uncorrected HOAs. We found that when HOAs were corrected, children and adults both showed improvements in MTF and CSF. However, the CSF of children was still lower than the adult level, indicating the difference in contrast sensitivity between groups cannot be explained by differences in optical factors. Further study showed that the difference between the groups also could not be explained by differences in non-visual factors. With these results we concluded that the neural systems underlying vision in children of around 8 years old are still immature in contrast sensitivity.

Training to improve contrast sensitivity in amblyopia: correction of high-order aberrations

“…The wave-front aberrations were measured during the CSF tests and training sessions and used to calculate the horizontal modulation transfer functions (MTFs) 32 under the two conditions. After the pre-training tests, the cut-off spatial frequencies 16 17 18 29 30 31 under the two conditions were collected, and training sessions with AO correction were performed on consecutive days. A contrast detection task was used for the CSF measurement and perceptual learning task, but at different spatial frequencies 16 17 18 29 30 31 .…”

“…After the pre-training tests, the cut-off spatial frequencies 16 17 18 29 30 31 under the two conditions were collected, and training sessions with AO correction were performed on consecutive days. A contrast detection task was used for the CSF measurement and perceptual learning task, but at different spatial frequencies 16 17 18 29 30 31 . In the CSF measurement, seven spatial frequencies (i.e., 0.6, 1, 2, 4, 8, 16, 24 cpd) were included, whereas in the perceptual learning task, the trained spatial frequency was set at the cut-off spatial frequency in the pre-training CSF test with AO correction 18 30 .…”

“…A contrast detection task conducted at the individual’s cut-off spatial frequency was used as the training protocol. This task was similar to those in previously reported studies 16 17 18 29 30 31 and enabled us to directly compare the learning benefits among different studies. We found that the AOPL system worked well in terms of correcting HOAs, and the improvements in visual function induced by perceptual learning with adaptive optics (AO) correction were maintained in the condition not only with AO correction but also without AO correction.…”

High-gain visual feedback exacerbates ankle movement variability in children

“…There are four primary explanations that are not mutually exclusive: (1) Numerous neuroanatomic structures and physiologic processes are developing in preadolescent children (Eiland and Romeo 2013). For example, the visual system of children is immature compared with that of adults (Liu et al 2014). This is demonstrated by Liu et al (2014) as a lower contrast sensitivity function in children, which is considered to be the most fundamental assessment of the visual system (Martinez-Roda et al 2011;Michael et al 2011).…”

“…For example, the visual system of children is immature compared with that of adults (Liu et al 2014). This is demonstrated by Liu et al (2014) as a lower contrast sensitivity function in children, which is considered to be the most fundamental assessment of the visual system (Martinez-Roda et al 2011;Michael et al 2011). In addition, the deficient visuomotor integration observed in preadolescent children in this study and the study by Deutsch and Newell (2002) may be the consequence of immature cortical activation in specific areas of the brain.…”