Seeing is predicting: Testing a predictive coding account of visual perception involving saccadic eye movements

Projektbeschreibung

Verfolgen von Augenbewegungen und prädiktive Kodierung testen

Unsere Augen bewegen sich fortwährend und dabei analysieren und interpretieren wir komplexe visuelle Daten. Jede Sekunde machen wir etwa drei Sakkaden – schnelle Augenbewegungen, um die Fovea auf Objekte von visuellem Interesse zu lenken. Das heißt nicht, dass das Sehen instabil ist. Das Gegenteil ist der Fall. Im EU-finanzierten Projekt C-Pre wird untersucht, ob die prädiktive Kodierung und darin enthalten die Übertragung von Vorhersage- und Vorhersagefehlersignalen über neuronale Netze im Gehirn dies erklären kann. In diesem Projekt werden diese Signale verfolgt, um die Gehirnaktivität zu messen und sie zusammen mit experimentellen Designs zur Blickverfolgung aufzuzeichnen. Die Ergebnisse werden die Kognitionswissenschaften mit ihrem hochinnovativen Falsifikationsversuch einer einflussreichen Theorie weiter fördern.

Ziel

We make about three saccadic eye movements per second which bring about an abrupt and drastic change in visual input on the retina. However, visual perception seems remarkably stable. I want to determine whether this phenomenon can be explained by predictive coding. Crucial for predictive coding is the transmission of prediction and prediction error signals across brain networks. I want trace down these signals in humans with non-invasive neurophysiological and neuroimaging methods. I will record EEG and MEG data combined with eye-tracking in gaze-contingent experimental designs in which visual input changes during a saccade and in which the frequency of change is manipulate to affect higher-level trans-saccadic expectations. I will apply measures of information transfer and dynamic causal modelling to assess brain dynamics time-locked to saccadic eye-movements. This approach will provide evidence for or against pre-saccadic top-down prediction and post-saccadic bottom-up prediction error signals, which will eventually speak to the question whether predictive coding can explain the phenomenon of visual stability. The proposed action will strongly enhance my theoretical knowledge about predictive processes and it will widely extend my methodological skills about MEG, source analysis, and the analysis of brain dynamics and connectivity. The project will be conducted under the supervision of Floris de Lange at the Donders Institute, the Netherlands, and includes a secondment with Karl Friston and Rick Adams at UCL, UK, as well as cooperation with Stefano Panzeri from IIT, Italy. In sum, this project combines methods and approaches from an international set of world-leading experts in an unprecedented way to test a hypothesis derived from the currently most comprehensive theory of brain function. Therefore, this project will make a highly-innovative falsification attempt of an influential theory which could mean a crucial step in advancing the cognitive sciences.