Detailseite
Projekt Druckansicht

Optische Illusionen und deren Effekt auf Aufmerksamkeitsprozesse

Antragsteller Dr. Ralph Weidner
Fachliche Zuordnung Allgemeine, Kognitive und Mathematische Psychologie
Förderung Förderung von 2011 bis 2017
Projektkennung Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 198776157
 
Erstellungsjahr 2017

Zusammenfassung der Projektergebnisse

Overall, the present series of experiments investigated the functional mechanisms involved in generating perceived size representations and how these affect and interact with top-down processes. Our initial experiment (Experiment 1) directly addressed the role of perceived size changes on attentional orienting. This experiment revealed some counterintuitive results regarding the interaction between attention and perceived size changes and revealed general difficulties in disentangling lower level effects induced by illusion inducing figures and their effects on perceived size. Accordingly, a different paradigm was used which (Experiment 2) then allowed testing the temporal dynamics of context integration and the formation of perceived size. The results indicate that perceived size formation is fast (40 ms) and affects levels of processing that represent early stages of attentional processing involving saliency calculation. Several experiments using functional magnetic resonance imaging (fMRI) revealed that perceived size representations emerge from bi-directional interactions within a network consisting of bilateral ventral and right lateralized dorsal stream brain regions. Furthermore, our experiments suggest that the ventral stream regions, particularly V3v, play a major role in forming perceived size representations. In particular, we could demonstrate that left V3v is involved in integrating retinal size and distance information and that this brain area plays a key role in generating the moon illusion (Experiment 4). Furthermore, in an additional fMRI experiment using size-adaptation and a temporal version of the Ebbinghaus illusion we were able to separate visual activation related to the context that alters perceived size from those that are involved in size re-scaling (Experiment 5). This experiment provides direct behavioural and functional evidence for the presence of a neural bottleneck in rescaling retinal into perceived size, a process vital for visual perception. Functionally this bottleneck is found in left lingual gyrus, right supramarginal gyrus, and right superior parietal cortex. Finally, two experiments investigated the mechanisms underlying size-adaption as used in Experiment 5. The behavioural results indicate that the levels of processing underlying size adaptation are top-down penetrable and interact with top-down attention processes. The functional experiment performed has not yet been informative with regard to the functional mechanisms involved in this interaction between visual illusions and endogenous attention. Further experiments involving an improved experimental design are still needed.

Projektbezogene Publikationen (Auswahl)

 
 

Zusatzinformationen

Textvergrößerung und Kontrastanpassung