Der Einfluss von Wert auf die unbewusste sensorische Informationsverarbeitung
Kognitive und systemische Humanneurowissenschaften
Zusammenfassung der Projektergebnisse
This research project investigated the role of value in unconscious sensory information processing and the neuromodulatory mechanisms underlying perceptual decision-making. In a series of behavioural experiments, including experiments in combination with eyetracking, we studied whether visual stimuli associated with a high monetary reward would gain a more rapid access to awareness compared to stimuli associated with a lower reward. Contrary to our a priori hypothesis, we did not observe that stimuli gained faster access to awareness through their association with higher rewards. However, pupillometric analyses yielded an increase in pupil size for rewarding outcomes during the consciously visible feedback phase, likely reflecting participants’ motivational level. Our findings thus suggest that during perceptual decision-making value is only integrated at later stages of sensory information processing. As such, our findings provide an important contribution to the longstanding debate of the scope and limits of unconscious visual processing. In a further theoretical paper, we point out that future studies investigating the influence of subliminal stimuli on behaviour should follow rigorous methodological standards and refrain from post-hoc data selection, as this likely leads to an overestimation of unconscious influences on behaviour. A second focus of the research project aimed at elucidating the neuromodulatory mechanisms underlying perceptual decisionmaking. Using a behavioural paradigm in combination with a pharmacological manipulation, participants responded to an ambiguous stimulus during the administration of the NMDA-glutamat-receptor antagonist ketamine. We hypothesized that ketamine should lead to reduced feedback signaling of sensory predictions and thus a decreased prior-to-likelihood ratio in sensory processing. In our task, this would manifest in a higher congruency between participants’ perception and the actual sensory evidence. Our findings showed some indication of such a higher congruency under ketamine, tentatively suggesting a role of NMDA-receptor mediated feedback during perceptual decision-making. Taken together, the research project yielded new insights into the role of value in unconscious visual processing and the neuromodulatory mechanisms underlying perceptual decision-making. We believe that our findings can pave the way for a deeper understanding of the mechanisms underlying perceptual alterations in psychiatric disorders, such as psychotic experiences in schizophrenia or biased visual information processing in depression and anxiety disorders.
Projektbezogene Publikationen (Auswahl)
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Associations with monetary values do not influence access to awareness for faces. PeerJ, 9, e10875.
Rothkirch, Marcus; Wieser, Maximilian & Sterzer, Philipp
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The effect of reward on preconscious visual processing [Abstract]. Perception, 50(IS), 228-229.
Rothkirch, M., Lee, Y., & Sterzer, P.Rothkirch, M., Lee, Y. & Sterzer, P.
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Useful misrepresentation: perception as embodied proactive inference. Trends in Neurosciences, 44(8), 619-628.
Martin, Joshua M.; Solms, Mark & Sterzer, Philipp
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The Pervasive Problem of Post Hoc Data Selection in Studies on Unconscious Processing. Experimental Psychology, 69(1), 1-11.
Rothkirch, Marcus; Shanks, David R. & Hesselmann, Guido
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The value of confidence: Confidence prediction errors drive value-based learning in the absence of external feedback. PLOS Computational Biology, 18(10), e1010580.
Ptasczynski, Lena Esther; Steinecker, Isa; Sterzer, Philipp & Guggenmos, Matthias
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When seeing is not believing: A mechanistic basis for predictive divergence. Consciousness and Cognition, 102, 103334.
Caporuscio, Chiara; Fink, Sascha Benjamin; Sterzer, Philipp & Martin, Joshua M.
