2020/04/30 by Sascha Meyen, Iris A. Zerweck, Meyen, Sascha +7 · 2 citations
Neuroscience · #Neural and Behavioral Psychology Studies #EEG and Brain-Computer Interfaces #Neural dynamics and brain function
paper · pdf · doi:10.48550/arxiv.2004.14987
Current literature holds that many cognitive functions can be performed\noutside consciousness. Evidence for this view comes from unconscious priming.\nIn a typical experiment, visual stimuli are masked, such that participants are\nclose to chance when directly asked to which of two categories the stimuli\nbelong. This close-to-zero sensitivity is seen as evidence that participants\ncannot consciously report the category of the masked stimuli. Nevertheless, the\ncategory of the masked stimuli can indirectly affect responses to other stimuli\n(e.g., reaction times or brain activity). Priming is therefore seen as evidence\nthat there is still some (albeit unconscious) sensitivity to the stimulus\ncategories, thereby indicating processing outside consciousness. Although this\n"standard reasoning of unconscious priming" has been used in many studies, we\nshow that it is flawed: Sensitivities are not calculated appropriately, hereby\ncreating the wrong impression that priming indicated better sensitivity than\nthe close-to-zero sensitivity of the direct discrimination. We describe the\nappropriate way to determine sensitivities, replicate the behavioral part of a\nlandmark study, develop a method to estimate sensitivities for published\nstudies from reported summary statistics, and use this method to reanalyze 15\nhighly influential studies. Results show that the interpretations of many\nstudies need to be changed and that a community effort to reassess the vast\nliterature on unconscious priming is needed. This process will allow scientists\nto learn more about the true boundary conditions of unconscious priming,\nthereby advancing the scientific understanding of consciousness.\n