Marciano Hadas, Yeshurun Yaffa
The Institute of Information Processing and Decision Making, University of Haifa, Haifa, Israel.
Department of Psychology, University of Haifa, Haifa, Israel.
PLoS One. 2017 Apr 13;12(4):e0175060. doi: 10.1371/journal.pone.0175060. eCollection 2017.
This study examined whether the recurrent difficulty to replicate results obtained with paradigms measuring distractor processing as a function of perceptual load is due to individual differences. We first reanalyzed, at the individual level, the data of eight previously reported experiments. These reanalyses revealed substantial inter-individual differences, with particularly low percentage of participants whose performance matched the load theory's predictions (i.e., larger distractor interference with low than high levels of load). Moreover, frequently the results were opposite to the theory's predictions-larger interference in the high than low load condition; and often a reversed compatibility effect emerged-better performance in the incompatible than neutral condition. Subsequently, seven observers participated in five identical experimental sessions. If the observed inter-individual differences are due to some stable trait or perceptual capacity, similar results should have emerged in all sessions of a given participant. However, all seven participants showed large between-sessions variations with similar patterns to those found between participants. These findings question the theoretical foundation implemented with these paradigms, as none of the theories suggested thus far can account for such inter- and intra-individual differences. Thus, these paradigms should be used with caution until further research will provide better understanding of what they actually measure.
本研究考察了在测量作为知觉负载函数的干扰项加工时，反复难以复制所获结果是否归因于个体差异。我们首先在个体层面重新分析了先前报道的八项实验的数据。这些重新分析揭示了个体间的显著差异，表现符合负载理论预测的参与者比例尤其低（即，低负载水平下的干扰项干扰大于高负载水平）。此外，结果常常与该理论的预测相反——高负载条件下的干扰大于低负载条件；并且经常会出现反向的兼容性效应——不兼容条件下的表现优于中性条件。随后，七名观察者参与了五个相同的实验环节。如果观察到的个体间差异是由于某种稳定特质或知觉能力导致的，那么在给定参与者的所有环节中应该会出现相似的结果。然而，所有七名参与者在各环节之间均表现出较大差异，且模式与在参与者之间发现的相似。这些发现对使用这些范式的理论基础提出了质疑，因为迄今为止提出的所有理论都无法解释这种个体间和个体内的差异。因此，在进一步研究能更好地理解它们实际测量的内容之前，应谨慎使用这些范式。
