Lynn Margaret T, Demanet Jelle, Krebs Ruth M, Van Dessel Pieter, Brass Marcel
Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000, Ghent, Belgium.
Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium.
Brain Struct Funct. 2016 Apr;221(3):1309-20. doi: 10.1007/s00429-014-0972-9. Epub 2014 Dec 24.
Behavioral inhibition has classically been considered to rely upon a neural network centered at the right inferior frontal cortex [rIFC; Aron et al. (8:170-177, 2004; 18:177-185, 2014)]. However, the vast majority of inhibition studies have entailed exogenous stop signals instructing participants to withhold responding. More recent work has begun to examine the neural underpinnings of endogenous inhibition, revealing a distinct cortical basis in the dorsal fronto-median cortex [dFMC; Brass and Haggard (27:9141-9145, 2007); Kühn et al. (30:2834-3843, 2009)]. Yet, contrary to everyday experiences of voluntary behavioral suppression, the paradigms employed to investigate action inhibition have thus far been somewhat artificial, and involve little persuasive motivation to act. Accordingly, the present fMRI study seeks to compare and contrast intentional with instructed inhibition in a novel pain paradigm that recruits 'hot' incentive response systems. Participants received increasing thermal stimulation to their inner wrists, and were required to occasionally withhold their natural impulse to withdraw from the compelling pain sensation at peak temperature, in both instructed and free-choice conditions. Consistent with previous research, we observed inhibition-related activity in the dFMC and the rIFC. However, these regions displayed equivalent activation levels for both inhibition types. These data extend previous research by demonstrating that under ecologically valid conditions with a strong motivation to act, both stopping networks operate in concert to enable suppression of unwanted behavior.
行为抑制传统上被认为依赖于以右下额叶皮质[rIFC；Aron等人（8:170 - 177，2004；18:177 - 185，2014）]为中心的神经网络。然而，绝大多数抑制研究都涉及外源性停止信号，指示参与者抑制反应。最近的研究开始探讨内源性抑制的神经基础，揭示了背侧额中皮质[dFMC；Brass和Haggard（27:9141 - 9145，2007）；Kühn等人（30:2834 - 3843，2009）]中有不同的皮质基础。然而，与日常自愿行为抑制的经验相反，迄今为止用于研究动作抑制的范式有些人为，并且几乎没有令人信服的行动动机。因此，本功能磁共振成像研究旨在在一种招募“热”激励反应系统的新型疼痛范式中比较和对比有意抑制与指令性抑制。参与者接受对内腕不断增强的热刺激，并被要求在指令性和自由选择条件下，在温度峰值时偶尔抑制因强烈疼痛感觉而自然产生的缩回冲动。与先前的研究一致，我们在背侧额中皮质和右下额叶皮质中观察到了与抑制相关的活动。然而，这两个区域在两种抑制类型中显示出相同的激活水平。这些数据扩展了先前的研究，表明在具有强烈行动动机的生态有效条件下，两个停止网络协同运作以抑制不必要的行为。
