Henderson Jessica, Mari Tyler, Hopkinson Andrew, Hewitt Danielle, Newton-Fenner Alice, Giesbrecht Timo, Marshall Alan, Stancak Andrej, Fallon Nicholas
School of Psychology, University of Liverpool, Liverpool, United Kingdom.
Hopkinson Research, Wirral, United Kingdom.
Front Neurosci. 2023 Jun 2;17:1197113. doi: 10.3389/fnins.2023.1197113. eCollection 2023.
Texture changes occur frequently during real-world haptic explorations, but the neural processes that encode perceptual texture change remain relatively unknown. The present study examines cortical oscillatory changes during transitions between different surface textures during active touch.
Participants explored two differing textures whilst oscillatory brain activity and finger position data were recorded using 129-channel electroencephalography and a purpose-built touch sensor. These data streams were fused to calculate epochs relative to the time when the moving finger crossed the textural boundary on a 3D-printed sample. Changes in oscillatory band power in alpha (8-12 Hz), beta (16-24 Hz) and theta (4-7 Hz) frequency bands were investigated.
Alpha-band power reduced over bilateral sensorimotor areas during the transition period relative to ongoing texture processing, indicating that alpha-band activity is modulated by perceptual texture change during complex ongoing tactile exploration. Further, reduced beta-band power was observed in central sensorimotor areas when participants transitioned from rough to smooth relative to transitioning from smooth to rough textures, supporting previous research that beta-band activity is mediated by high-frequency vibrotactile cues.
The present findings suggest that perceptual texture change is encoded in the brain in alpha-band oscillatory activity whilst completing continuous naturalistic movements across textures.
在现实世界的触觉探索过程中，质地变化频繁发生，但编码感知质地变化的神经过程仍相对未知。本研究考察了主动触摸过程中不同表面质地转换期间的皮层振荡变化。
参与者探索两种不同的质地，同时使用129通道脑电图和特制的触摸传感器记录大脑振荡活动和手指位置数据。将这些数据流融合，以计算相对于移动手指在3D打印样本上越过质地边界的时间的时段。研究了α（8 - 12赫兹）、β（16 - 24赫兹）和θ（4 - 7赫兹）频段振荡带功率的变化。
相对于正在进行的质地处理，在过渡期双侧感觉运动区域的α频段功率降低，表明在复杂的持续触觉探索过程中，α频段活动受到感知质地变化的调制。此外，当参与者从粗糙质地过渡到光滑质地时，相对于从光滑质地过渡到粗糙质地，在中央感觉运动区域观察到β频段功率降低，支持了先前的研究，即β频段活动由高频振动触觉线索介导。
本研究结果表明，在大脑中，感知质地变化是通过α频段振荡活动编码的，同时在跨质地完成连续自然运动的过程中也是如此。
