Department of Psychology, Stockholm University, Frescati Hagväg 9, 106 91 Stockholm, Sweden.
Cogn Affect Behav Neurosci. 2012 Mar;12(1):151-60. doi: 10.3758/s13415-011-0072-8.
Previous research suggests that intense, emotional pictures at fixation elicit an early posterior negativity (EPN) and a late positive potential (LPP) despite manipulations of spatial inattention and perceptual load. However, if high emotional intensity protects against such manipulations, then these manipulations should reduce emotional effects on EPN and LPP more strongly for medium than for intense emotional pictures. To test this prediction, pictures that were high negative, medium negative, or neutral were shown at fixation, and a small letter string was superimposed on the picture center. When participants attended the pictures, there were clear emotional effects on EPN and LPP. When participants attended the letter string, the emotional effects on LPP decreased; this decrease was smaller for medium than for high negative pictures. Thus, opposite of predictions, spatial inattention reduced the emotional effects more strongly for high than for medium negative pictures. As a manipulation of perceptual load, participants performed the letter task with one, three, or six relevant letters. Irrespective of load, EPN and LPP were similar for high and medium negative pictures. Our findings suggest that high negative valence does not protect EPN and LPP more strongly from effects of spatial inattention and perceptual load than does medium negative valence.
先前的研究表明,即使在空间注意力和感知负载的操纵下,强烈的情感图片在注视时也会引起早期后部负向波(EPN)和晚期正性电位(LPP)。然而,如果高情绪强度可以防止这种操纵,那么这些操纵对于中等强度的情感图片应该比强烈情感图片更能降低 EPN 和 LPP 的情感效应。为了验证这一预测,在注视时显示高负性、中负性或中性的图片,并在图片中心叠加一个小字母串。当参与者注视图片时,EPN 和 LPP 上会出现明显的情感效应。当参与者关注字母串时,LPP 上的情感效应会降低;与高负性图片相比,这种降低在中负性图片中较小。因此,与预测相反,空间注意力对高负性图片的情感效应的削弱作用强于中负性图片。作为感知负载的一种操纵,参与者用一个、三个或六个相关的字母执行字母任务。无论负载如何,高负性和中负性图片的 EPN 和 LPP 都相似。我们的研究结果表明,高负性效价并不能比中负性效价更有效地保护 EPN 和 LPP 免受空间注意力和感知负载的影响。