These neural modifications indicate the presence of brain plasticity.
Through these precise controlled conditions, repetitive practice initiates neural modifications that lead to improvement in neuronal efficiency. 12 – 18 It was shown that visual performance improves with repetitive practice on specific controlled visual tasks. Brain plasticity in visual functions of adults has been shown in various studies. The term perceptual learning describes a process whereby practicing certain visual talks leads to an improvement in visual performance. Lateral “masking” technique, where colinearly oriented flanking Gabors are displayed in addition to the target Gabor image. 6, 7 Polat and colleagues 8 – 11 demonstrated that contrast sensitivity at low levels can be increased dramatically through a “lateral masking” technique, where colinearly oriented flanking Gabors are displayed in addition to the target Gabor image ( Figure 2).
#REVITALVISION SOFTWARE PATCH#
The typical building block of the visual stimulus in the field of visual neuroscience is a Gabor patch ( Figure 1), which efficiently activates and matches the shape of receptive fields in the visual cortex. Several studies have shown that the noise of individual cortical neurons can be modulated by appropriate choice of stimulus conditions and that contrast sensitivity at low levels can be increased through control of stimulus parameters. Thus improvement of the signal-to-noise ratio leads to substantially improved visual performance. This creates a signal-to-noise ratio that determines detection and limits the CSF. 1, 3, 4 The brain pools response across many neurons to average out noise activity of single cells. 2Įxperiments have shown that the response of individual neurons to repeated stimulus (noise) is highly variable: this high noise level imposes a fundamental limitation on the reliable detection and discrimination of visual signals by individual cortical neurons.
The combination of neural interactions at various spatial frequencies results in individual contrast sensitivity function (CSF). 1 Neural interactions determine contrast sensitivity at each spatial frequency. Optical images from the retina travel through a hierarchy of progressive levels of visual processing, from photoreceptors through several stages of spatial integration, each forming receptive fields of increasing complexity.Ĭontrast is one of the most important parameters triggering the neural activity in the visual cortex. The human visual system consists of a highly sophisticated optical processing system.
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