Neurobiology of specific and general prior knowledge

To understand the world around us we largely rely on our prior knowledge, which can help us structure newly incoming information. My research implemented naturalistic fMRI studies to investigate how previously acquired information affects the encoding and retrieval of new, but related, events. It is important to note that our stored knowledge can be either more general (schematic) knowledge – such as what typically happens at restaurants – or can be referring to a specific event – such as when we start listening to a lecture to which we have missed the beginning. In my first experiment I focused on examining effects of more specific prior knowledge. I presented participants with the first and second halves of clips. The speech in some of the first half videos was made unintelligible. The second half clips were identical for everyone. This design allowed me to investigate how we integrate prior (topic specific) information with newly incoming information. I observed better memory for the clips for which prior information was provided. Interestingly I also observed higher brain activity synchronization across participants sharing the same prior knowledge in a subset of brain regions. This result suggested that these brain regions play a role in the integration of new and prior information. In a separate experiment I examined the effects of more generic prior knowledge. I familiarised participants over the course of a week with one of two shows. Inside the scanner participants performed a picture and a video clip task. In the picture task participants watched pictures of characters that were either from the trained or the untrained show. I found higher activations in ventromedial prefrontal cortex, hippocampus and retrosplenial cortex when participants were viewing pictures from the trained show versus the untrained show. In the video task I asked participants to watch and recall previously unseen clips from both the trained and untrained shows. I observed higher pattern similarity between trained clips when compared to the untrained clips, in frontal regions suggesting that they are involved in maintaining schema knowledge during encoding of new information. Apart from schema knowledge effects, I ran a project where I examined which brain regions might be particularly important for representing knowledge about social categories. I have also examined event cognition in individuals with mild cognitive impairment