Division of Biotechnology, Institute of Convergence Research, DGIST, Daegu, Republic of Korea.
Department of Interdisciplinary Studies, DGIST, Daegu, Republic of Korea.
BMC Res Notes. 2023 Nov 1;16(1):304. doi: 10.1186/s13104-023-06588-5.
Noninvasive neural decoding enables predicting motor output from neural activities without physically damaging the human body. A recent study demonstrated the applicability of functional near-infrared spectroscopy (fNIRS) to decode muscle force production from hemodynamic signals measured in the male brain. However, given the sex differences in cerebral blood flow and muscle physiology, whether the fNIRS approach can also be applied to the female brain remains elusive. Therefore, this study aimed to evaluate whether fNIRS can be used to identify the optimal cortical region and hemodynamic predictor to decode muscle force output in females.
Statistical group analysis for eight healthy female adults showed that the cortical region for wrist control was topologically dorsal to that for finger control over the primary sensorimotor cortex. This cortical area was maximally activated while the wrist flexor muscles were contracted to hold a load on the subject's palm, as was the case for males. However, the dynamics of oxyhemoglobin concentration measured from the most activated cortical area differed between females and males. The signal intensity during 100% maximal voluntary contraction and the signal increase rate at 50% maximal voluntary contraction was lower and faster in females. Eight predictors were used to characterize hemodynamic signals' amplitude and temporal variation in the female cortex. Unlike the case for males, only the trajectory predictors for the amplitude of oxyhemoglobin concentration change were strongly correlated with the strengths of force produced by the wrist flexor muscles, showing a linear relationship. These results suggest gender-specific hemodynamics must be considered for decoding low-level motor control with fNIRS in females.
无创神经解码可在不损伤人体的情况下，根据神经活动预测运动输出。最近的一项研究表明，功能近红外光谱（fNIRS）可用于从男性大脑中测量的血液动力学信号解码肌肉力量产生。然而，鉴于大脑血液流动和肌肉生理学方面的性别差异，fNIRS 方法是否也适用于女性大脑仍不得而知。因此，本研究旨在评估 fNIRS 是否可用于识别最佳皮质区域和血液动力学预测因子，以解码女性的肌肉力量输出。
对 8 名健康成年女性进行的统计组分析表明，用于腕部控制的皮质区域在初级感觉运动皮质上的拓扑学上位于手指控制区域的背部。当腕部屈肌收缩以在受试者手掌上保持负荷时，该皮质区域被最大程度地激活，就像男性一样。然而，从最活跃的皮质区域测量的氧合血红蛋白浓度的动力学在女性和男性之间有所不同。在 100%最大自主收缩期间的信号强度和 50%最大自主收缩时的信号增加率在女性中较低且较快。使用 8 个预测因子来描述女性皮质中的血液动力学信号幅度和时间变化。与男性不同，只有氧合血红蛋白浓度变化幅度轨迹预测因子与腕部屈肌产生的力强度强烈相关，表现出线性关系。这些结果表明，在女性中使用 fNIRS 进行低水平运动控制解码时，必须考虑特定于性别的血液动力学。
