Investigating the neural mechanisms of visual contextual memory: from learning to exploitation

• Applicant: Professor Dr. Niko Busch, since 11/2016
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 229558394

Objects maintain regular associations with their usual context and we have the ability to unconsciously use these regularities to guide our behavior. Although behavioral experiments have well characterized the psychological mechanisms whereby we learn and use contextual regularities, we know little about the underlying neural mechanisms. In this project we present four experiments to explore two main propositions concerning the neural mechanisms of the memory for contextual regularities. We will first elaborate on our previous findings about the role of oscillations in the gamma frequency range (around 40 Hz) occurring in the electroencephalogram (EEG) during the learning of contextual regularities. Second, we will explore the role of rest in this learning.Our previous work has begun to reveal key processes occurring during the learning and exploiting of visual contextual regularities. Specifically, we have shown that rapid oscillations (in the gamma-frequency band) occur during learning, and we suggested that these oscillations participate to the creation of a neural representation of the contextual regularities -- a process that we term here the gamma-band sharpening hypothesis. We will test the generality of the gamma-band sharpening hypothesis by examining effects of context on motor stages in one EEG experiment.In addition, our previous results and recent research investigating brain activations during rest periods suggest that brain activity at rest might participate to learning contextual regularities. We hypothesize that the short periods of rest usually given to participants in an experiment are important for learning. We will manipulate our participants' activity during rest and measure the effects this has on learning contextual regularities, both at the behavioral and at the neural level. We will record our participants' EEG and test the hypothesis that impaired learning will also be associated with a disrupted development of the gamma-band correlates of learning.We know that the during rest the brain is in fact highly active, in particular activation during rest can be found in a well characterized brain network called the default-mode network. In the last part of this project, we will test the hypothesis that activity in this network is essential in learning contextual regularities. To test this hypothesis, we will need to measure the gamma-band correlates of learning and measure concomitant activity in the default mode network, which requires performing a joint EEG-fMRI experiment.This project is based on a well established research tradition, but tests novel hypotheses relating two weakly communicating fields (vision research and resting state research), and thus offers great potential for findings that will interest a large part of the neuroscience community internationally.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Maximilien Chaumon, Ph.D., until 11/2016