Rapid Alternate Flicker Modulates Binocular Interaction in Adults With Abnormal Binocular Vision

Abstract

Purpose The current understanding of binocular processing is primarily derived from static spatial visual perception: this leaves the role of temporal information unclear. In this study, we addressed this gap by testing the effect of alternating flicker on binocular information processing in adults with abnormal binocular vision. Our goal was to determine which temporal frequency optimally balanced input from both eyes. Methods We took measurements in four groups of human adults: 10 normal adults with the individual's nondominant eye covered by a 2% neutral density filter (aged 25.60 ± 1.43 years, experiment 1), 9 nonamblyopic anisometropes (aged 24.33 ± 1.66 years, experiment 2), 7 amblyopes (aged 26.5 ± 1.64 years, experiment 3), and 7 treated amblyopes (aged 24 ± 3.21 years, experiment 4). The balance point (BP), where participants’ two eyes are equally effective, was measured using a binocular orientation combination task at four spatial frequencies (SFs; 0.5–4 c/d) and five temporal frequencies (TFs; baseline and 4, 7, 10, and 15 Hz). Its log transformation |logBP| was taken into further analysis. Results We observed clear U-shaped temporal tuning of the |logBP| for the entire range of TFs (that we measured: trough occurred at 7 Hz). This pattern occurred and was significant in all four groups ( P < 0.001). In addition, the effect of SFs on |logBP| was significant in normal, amblyopic, and treated amblyopic groups (all P < 0.001) and was marginally significant in the nonamblyopic anisometropic group ( P = 0.086). Conclusions Alternating flicker around 7 Hz may be the optimal temporal frequency for balancing eyes in human adults with binocular imbalance.

Effects of Monocular Flicker on Binocular Imbalance in Amblyopic and Nonamblyopic Adults

“…Previous research on flicker stimuli 25 indicated that flickering could alter luminance transmission, leading to a decrease in the average luminance in front of the flickered eye. Although luminance reduction in one eye could lessen its contribution in binocular integration, 35 – 37 could the flickering-induced luminance transmission alternation explain the temporal frequency dependency pattern found in the current study?…”

“…First, for instance, Schor et al 24 demonstrated that alternately presenting targets to the two eyes at 2 and 7 Hz in amblyopia potentially enables better visual acuity under binocular viewing compared with other temporal frequencies. Next, our preliminary research 25 indicated that binocular alternating flicker at 7 Hz (where flicker stimuli are presented alternately in front of each eye with a 1:1 ratio of light to dark through liquid crystal spectacles) enables better binocular balance in amblyopia. Modulation of binocular imbalance via flicker can also reveal further insights regarding the neural underpinnings of amblyopia: several studies using synchronous binocular flicker (where stimuli are flickered simultaneously in front of both eyes) have observed a slightly larger interocular imbalance at low temporal frequencies in amblyopia.…”

Research on the Multimode Switching Control of Intelligent Suspension Based on Binocular Distance Recognition

“…In contrast, semiactive suspensions are less costly and have an adjustable damping force. By applying control algorithms to semiactive suspensions, they can be adaptively adjusted according to the current and future road conditions, which is a better choice for suspension systems currently [2][3][4][5].…”