Oliveira Anderson Souza, Arguissain Federico Gabriel, Andersen Ole Kæseler
Department of Materials and Production, Aalborg University, Fibigerstræde 16, Building 4, 9220, Aalborg E, Denmark.
Integrative Neuroscience Group, SMI®, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D3, 9220, Aalborg E, Denmark.
Brain Topogr. 2018 Jul;31(4):661-671. doi: 10.1007/s10548-018-0633-z. Epub 2018 Feb 10.
The aim of this study was to investigate whether cognitive processing for defining step precision during walking could induce changes in electrocortical activity. Ten healthy adults (21-36 years) were asked to walk overground in three different conditions: (1) normal walking in a straight path (NW); (2) walking in a pre-defined pathway forcing variation in step width and length by stepping on green marks on the floor (only one color: W1C), and (3) walking in the same pre-defined W1C pathway while evaluating different combinations among the colors green, yellow and red, in which only one color was the footfall target (evaluating two colors: W2C). Walking speed, stride duration and scalp electroencephalography (EEG) were recorded from all conditions. Event-related spectral perturbation was calculated for channels Fz, Cz, C3, C4, Pz and Oz in each condition, which were all time-normalized in relation to the gait cycle. The results showed that walking speed was reduced and stride duration was increased for W2C when compared to both NW and W1C (p < 0.01). Moreover, Event-related spectral perturbation analysis revealed significant changes (p < 0.05) during mid-stance in the frontal lobe and motor/sensorimotor regions, a phase in the gait cycle in which participants define the correct foot placement for the next step. These results suggest that greater cognitive demands during precision stepping influences electrocortical dynamics especially towards step transitions. Therefore, increased electrocortical activity in cognitive, motor and sensorimotor areas may be relevant to produce patterned and safe locomotion through challenging paths.
本研究的目的是调查在行走过程中用于定义步幅精度的认知加工是否会引起脑电活动的变化。10名健康成年人（21 - 36岁）被要求在三种不同条件下在地面行走：（1）在直线路径上正常行走（NW）；（2）在预先定义的路径上行走，通过踩在地板上的绿色标记来迫使步幅宽度和长度发生变化（只有一种颜色：W1C），以及（3）在相同的预先定义的W1C路径上行走，同时评估绿色、黄色和红色之间的不同组合，其中只有一种颜色是落足目标（评估两种颜色：W2C）。记录所有条件下的行走速度、步幅持续时间和头皮脑电图（EEG）。针对每种条件下的Fz、Cz、C3、C4、Pz和Oz通道计算事件相关频谱微扰，这些通道均相对于步态周期进行了时间归一化。结果表明，与NW和W1C相比，W2C的行走速度降低且步幅持续时间增加（p < 0.01）。此外，事件相关频谱微扰分析显示，在额叶和运动/感觉运动区域的站立中期，即步态周期中参与者为下一步确定正确足部位置的阶段，存在显著变化（p < 0.05）。这些结果表明，精确迈步过程中更高的认知需求会影响脑电动力学，尤其是在步幅转换方面。因此，认知、运动和感觉运动区域脑电活动的增加可能与通过具有挑战性的路径产生有模式且安全的运动有关。
