Medina Jared, Theodoropoulos Nikolaos, Liu Yuqi, Reyes Patrick G, Gherri Elena
Department of Psychology, University of Delaware, United States of America.
Department of Psychology, The University of Edinburgh, United Kingdom of Great Britain and Northern Ireland.
Acta Psychol (Amst). 2019 Jul;198:102874. doi: 10.1016/j.actpsy.2019.102874. Epub 2019 Jul 9.
Previous studies have demonstrated a tactile Simon effect in which stimulus codes are generated based on the stimulated hand, not on limb position in external space (the somatotopic Simon effect). However, given evidence from visual Simon effect studies demonstrating that multiple stimulus codes can be generated for a single stimulus, we examined whether multiple stimulus codes can be generated for tactile stimuli as well. In our first experiment using four stimulators (two on each side of the hand), we found novel evidence for a hand-centered Simon effect, along with the typical somatotopic Simon effect. Next, we examined whether the potential salience of these somatotopic codes could be reduced, by testing only one hand with two stimulators attached. In Experiments 2-4, we found a strong hand-centered Simon effect with a diminished somatotopic Simon effect, providing evidence that stimulus salience can change the weighting of somatosensory stimulus coding. Finally, we also found novel evidence that the hand-centered Simon effect is coded in external, not somatotopic, coordinates. Furthermore, the diminished somatotopic Simon effect when testing on one hand only provides evidence that salience is an important factor in modulating the tactile Simon effect.
先前的研究已经证明了一种触觉西蒙效应，即刺激编码是基于受刺激的手生成的，而不是基于外部空间中的肢体位置（躯体定位西蒙效应）。然而，鉴于视觉西蒙效应研究的证据表明，对于单个刺激可以生成多个刺激编码，我们研究了触觉刺激是否也能生成多个刺激编码。在我们的第一个实验中，使用了四个刺激器（手部两侧各两个），我们发现了以手为中心的西蒙效应的新证据，以及典型的躯体定位西蒙效应。接下来，我们通过仅测试一只附着有两个刺激器的手，研究了这些躯体定位编码的潜在显著性是否可以降低。在实验2至4中，我们发现了强烈的以手为中心的西蒙效应，而躯体定位西蒙效应减弱，这证明了刺激显著性可以改变体感刺激编码的权重。最后，我们还发现了新的证据，即以手为中心的西蒙效应是在外部而非躯体定位坐标中编码的。此外，仅测试一只手时躯体定位西蒙效应的减弱提供了证据，表明显著性是调节触觉西蒙效应的一个重要因素。
