Neural noise as a characteristic feature and target for amblyopia treatment

Abstract

Today, considerable attention is being paid to the clinical efficacy of new amblyopia treatments, such as TMS and tDCS, as well as perceptual and dichoptic visual training in video games, including those using virtual and augmented reality. The aim is to improve binocular vision and reduce interocular suppression. Recent advances in neuroscience provide new insights into the mechanisms of therapeutic effects and identify new research directions in this area. In particular, studies of evoked and spontaneous neural activity (background noise) are expanding our understanding of visual system function. Normal background neural activity exhibits complex, self-similar scale-free oscillations, the power spectrum of which can be described by a 1/f function. A 1/f-like power spectrum indicates nonlinear, fractal dynamics of neural activity. In amblyopia, the variability of not only evoked but also background neural activity increases, which can negatively affect brain plasticity and the statistical properties of oscillations. The dynamics of background noise determine the variability of the evoked response and may influence brain plasticity. It is believed that the superior efficacy of new amblyopia treatments used today, compared to traditional methods, is due to their ability to better train the brain to distinguish signals from noise, thereby enhancing the reliability of received visual information. On the other hand, fractal photostimulation has been shown to have a positive effect on evoked retinal bioelectrical activity and visual characteristics in patients with various retinal diseases. This may be due to the normalization of the statistical characteristics of neural noise in the visual system, both stimulus-dependent (evoked visual responses) and background noise of spontaneous neuronal activity at rest. It can be hypothesized that the development of new pharmacological and non-pharmacological methods for modulating neuroplasticity will facilitate the restoration of the structure and function of neural networks and the visual rehabilitation of patients with amblyopia.