15:00 - 16:30
Talk Session VII
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15:00 - 16:30
Wed-HS1-Talk VII-
Wed-Talk VII-
Room: HS1
Chair/s:
Simone Malejka
Can we detect regularities in our environment and adapt behavior accordingly in the absence of awareness? The demonstration of unconscious (implicit) cognition hinges on participants’ unawareness of stimuli, processes, or products involved in a task. The gold standard is to establish an indirect-without-direct effect, that is, an uninstructed effect of a stimulus on behavior under conditions that preclude any effect of the stimulus on a response according to explicit instructions. This symposium will bring together researchers working on new methods tailored to investigate the possibility of indirect-without-direct effects. The first two talks will present novel indirect and direct
measures for well-known experimental paradigms. Sascha Meyen will demonstrate a new test of reaction-time differences, which offers an improved indirect measure and provides evidence against unconscious processing in contextual cueing. In the area of priming, Thomas Schmidt will talk about a new theory of visibility focusing on the critical stimulus feature that generates the indirect effect and must be assessed in the direct measure. The final three talks will present new analyses for data that presumably show an indirect-without-direct pattern. These data often suffer from regression to the mean (RttM), defined as the statistical phenomenon that makes natural variation in repeated data look like real change. When direct measures are contaminated with measurement error, low awareness scores will tend to be followed by awareness scores closer to the mean. Itay Yaron will outline a solution to the RttM problem that uses a widely applicable bootstrapping algorithm based only on a small set of assumptions. Simone Malejka will present a method of true-score estimation based on the Bayesian principle of shrinkage, which corrects noisy data and can solve RttM and related measurement biases. Lastly, Zoltan Dienes will demonstrate how Bayes factors can provide evidence for (or against) one’s theory in the presence of measurement error by testing an interval null hypothesis of zero awareness in post-hoc trial selection.
A theory of visibility measures in the dissociation paradigm
Wed-HS1-Talk VII-02
Presented by: Thomas Schmidt
Thomas Schmidt, Melanie Biafora
RPTU Kaiserslautern-Landau
Research on perception without awareness primarily relies on the dissociation paradigm, which compares a measure of awareness of a critical stimulus (direct measure) with a measure indicating that the stimulus has been processed at all (indirect measure). We argue that dissociations between direct and indirect measures can only be demonstrated with respect to the critical stimulus feature that generates the indirect effect, and the observer’s awareness of that feature, the critical cue. We expand Kahneman’s (1968) concept of criterion content to comprise the set of all cues that an observer actually uses to perform the direct task. Different direct measures can then be compared by studying the overlap of their criterion contents and their containment of the critical cue. Because objective and subjective measures may integrate different sets of cues, one measure generally cannot replace the other without sacrificing important information. Using a simple mathematical formalization, we redefine and clarify the concepts of validity, exclusiveness, and exhaustiveness in the dissociation paradigm, show how dissociations among different awareness measures falsify simple theories of "consciousness", and formulate the demand that theories of visual awareness should be sufficiently specific to explain dissociations among different facets of awareness.
Keywords: Awareness measures, dissociation paradigm, consciousness, psychophysics