Goal of the consortium
The goal of this project is the implementation of a systems neuroscience strategy to clarify key aspects of sensory processing. The overarching question of this project is concerned with how sensory signals generate neuronal maps, and result in complex behavior and memory formation?
Three common research questions unify the projects of the CRC:
- How does perceptual processing lead to neuronal and / or cortical plasticity?
- How does sensory integration lead to spatial and / or declarative representation?
- How does sensory learning enable the categorization of objects?
To achieve cognitive representation of sensory processes, sensory information derived from our senses (e.g. audition, vestibulation, olfaction/taste, somatosensation, nociception and vision) must, following its initial perception at the level of the sensor, be integrated at the level of the cortex. The transduction of this sensory information during first-order cortical integration, is followed by increasingly complex higher order processing, which enables the fine-tuning of the sensory percept such that behaviour and memory result.
In this collaborative research centre (Sonderforschungsbereich, SFB) our goal is to implement a systems neuroscience approach to clarify key aspects of sensory processing at the cortical level. To do this we study humans and animals and integrate our empirical observations into computational models. We are particularly interested in understanding how sensory information processing leads to learning and memory formation, or to higher order representations such as categorisation, spatial representation, and explicit memory.
In the current funding period of the SFB we observed that elevations in cortical excitability comprise a key element of perceptual learning. At the level of categorisation, we observed that the avian analog of the mammalian prefrontal cortex plays a critical role in this process. In humans, we observed that different forms of categorisation (e.g. that are abstraction- or exemplar-based), require processing in different brain structure constellations including distinct components of the medial temporal lobe. At the level of spatial memory processing in the hippocampus, we observed both empirically and computationally, that it is likely that it is the saliency and not the modality of the sense that drives synaptic encoding resulting in memory. These data also form the basis for a further computational model that proposes distinct roles for the hippocampus and neocortex in episodic and semantic memory consolidation.
Based on our current findings, we will focus in the second phase of the SFB on the clarification of how different cortical and subcortical structures interact in the enablement of information integration, on the scrutiny of the processes underlying the subsequent cortical reorganisation and plasticity, and on the mechanisms and brain structures that enable higher order representations of memory and sensory experience.
These levels are addressed by the two main research areas of the CRC, namely:
Research Area A: Neuronal processing and integration of sensory information
Research Area B: Sensory representation and memory.