Enhanced Plasticity of Human Evoked Potentials by Visual Noise During the Intervention of Steady-State Stimulation Based Brain-Computer Interface.

Jun Xie,Guanghua Xu,Min Li,Xingliang Han,Jing Wang,Chengcheng Han,Xingang Zhao

doi:10.3389/fnbot.2018.00082

Abstract

Neuroplasticity, also known as brain plasticity, is an inclusive term that covers the permanent changes in the brain during the course of an individual's life, and neuroplasticity can be broadly defined as the changes in function or structure of the brain in response to the external and/or internal influences. Long-term potentiation (LTP), a well-characterized form of functional synaptic plasticity, could be influenced by rapid-frequency stimulation (or “tetanus”) within in vivo human sensory pathways. Also, stochastic resonance (SR) has brought new insight into the field of visual processing for the study of neuroplasticity. In the present study, a brain-computer interface (BCI) intervention based on rapid and repetitive motion-reversal visual stimulation (i.e., a “tetanizing” stimulation) associated with spatiotemporal visual noise was implemented. The goal was to explore the possibility that the induction of LTP-like plasticity in the visual cortex may be enhanced by the SR formalism via changes in the amplitude of visual evoked potentials (VEPs) measured non-invasively from the scalp of healthy subjects. Changes in the absolute amplitude of P1 and N1 components of the transient VEPs during the initial presentation of the steady-state stimulation were used to evaluate the LTP-like plasticity between the non-noise and noise-tagged BCI interventions. We have shown that after adding a moderate visual noise to the rapid-frequency visual stimulation, the degree of the N1 negativity was potentiated following an ~40-min noise-tagged visual tetani. This finding demonstrated that the SR mechanism could enhance the plasticity-like changes in the human visual cortex.

Highlights

Neuroplasticity, known as brain plasticity and neural plasticity, is an inclusive term that covers the permanent changes in the brain during the life of an individual
The strength of the scalp EEG responses was modified via prolonged activation of the visual pathway to inspect the induction of long-term potentiation (LTP)-like plasticity reflected as changes in the amplitude of visual evoked potentials (VEPs)
These two phenomena have often been treated as arising from the same neuronal sources (Galambos et al, 1981; Bohórquez and Özdamar, 2008), where the VEP obtained from the initial transient period of the steady-state stimulus resemble a motion-onset VEP elicited by transient motion stimulation for neuroplasticity evaluation

Summary

Introduction

Neuroplasticity, known as brain plasticity and neural plasticity, is an inclusive term that covers the permanent changes in the brain during the life of an individual. Long-term potentiation (LTP) refers to an increased activity-dependent reorganization of the synaptic networks after persistent stimulation (Borroni et al, 2000; Cooke and Bliss, 2006), which fulfills many of the criteria for learning and memory (Bliss and Collingridge, 1993; Kandel, 2001). LTP was often induced by applying a rapid-frequency stimulation (or “tetanus”) to an afferent pathway. This tetanus ensures the concurrent pre- and post-synaptic depolarization, and increases excitability of the dendritic spines of the postsynaptic neurons, leading to a lasting enhancement of synaptic strength (Bliss and Lømo, 1973). Due to the invasive character of the above research, only a few in vivo human studies have been implemented far, limiting our understanding of neuroplasticity in the living human brain

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