Is pain-related fear a predictor of somatosensory hypervigilance in chronic low back pain patients?

Pain-related fear has been found to be associated with increased disability and increased pain perception in patients with chronic low back pain. A possible mechanism by which pain-related fear could lead to increased pain perception is heightened attention to somatosensory sensations. In the present study, chronic pain patients reporting either a high or low level of pain related fear and control participants performed an auditory reaction time task, while occasionally non-painful electrical stimuli--accompanied by threatening instructions--were given to the arm or back. In the primary task condition, participants had to perform the auditory task while ignoring the electrical stimuli. Next, the task was presented under dual task conditions in which participants had to respond both to tones as well as to detection of electrical stimuli. It was hypothesized that for the primary task, high fearful patients would show greater disruption of performance on the auditory task than low fearful patients and controls when stimuli were presented to the back. For the dual task, slower reaction times for the auditory task, in combination with faster detection of electrical stimuli was expected. The hypotheses were not confirmed but patients scoring high on pain-related fear did show an overall increase in reaction time for all conditions of the primary task, with or without simultaneous stimulation. Regression analyses demonstrated that high pain-related fear was associated with increased reaction time to tones both in patients and healthy controls, and that within patients pain-related fear was a better predictor of reaction time to tones than present pain intensity. The findings may be interpreted as showing that patients with elevated levels of pain-related fear habitually attend to somatic sensations, giving less priority to other attention-demanding tasks.     

图片和汉字的激活水平及知觉干扰效应的比较

研究使用8个残缺水平下的图片及其中文名（汉字双字词）为实验材料．试图比较图片与汉字双字词识别激活水平的差异,接着比较二者产生知觉于扰效应的条件,并把二者产生知觉于扰的条件与英文单词产生知觉于扰的条件进行比较。实验一结果发现,在材料较清晰的条件下,汉字双字词的命名成绩高于图片,表明汉字双字词的激活水平不比图片低,但在材料很残缺的条件下,汉字双字词的命名成绩低于图片。实验二发现双字词和图片在没有事先学习情况下都产生知觉干扰效应,已有研究表明单个汉字无需事先学习也可以产生干扰效应,而英文单词需要事先学习。因此,图片和汉字的干扰效应与英文单词的差别跟图片、汉字的激活水平比英文单词高有关。     

Stimulus size matters: do life-sized stimuli induce stronger embodiment effects in mental rotation?

Against the background of the embodied cognition approach this experiment investigated the influence of motor expertise on object-based vs. egocentric transformations in a chronometric mental rotation (MR) task using images of either the own or another person’s body as stimulus material. The present study aimed to clarify two issues: (1) whether stimulus size (life size vs. small) is able to induce embodiment effects and (2) which role self-awareness processes play when using stimuli of the own body. The same design was conducted twice using both small stimuli (Study 1) and life-size human figures (Study 2). Using life-sized figures in Study 2 resulted in an explicit advantage of self-related stimuli and improved performance for motor experts compared to non-motor experts in both object-based and egocentric transformations. In conclusion, these results suggest that life-sized figures do indeed induce stronger embodiment effects in MR.