Research line 3
Computational architecture of visual processing streams & Computational Brain Connectivity
Led by: Rainer Goebel - Profile page
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Computational architecture of visual processing streams
This research group aims to answer the question which neuronal representations are used in the brain and how they are processed to enable specific perceptual and cognitive functions. These questions are investigated by integrating high-resolution functional magnetic resonance imaging (fMRI) with columnar-level neural network modeling and the development of advanced analysis tools.
We still know little about the representations coded inside specialised brain areas and how complex features emerge from combinations of simpler features when we move from one area to the next. With high-field MRI scanners (7 Tesla and beyond), the achievable functional resolution reaches to the sub-millimeter level (500–1000 microns). This is important since neurons with similar response properties seem to spatially cluster into functional units (cortical columns) with a lateral extent of hundreds of microns. Studying the brain at columnar resolution seems to be the appropriate level to reveal the principles that the brain uses to code information. We believe that a massive attempt to crack the columnar-level code in as many areas as possible will ultimately lead to a deeper understanding how mind emerges from simpler units in the brain.
Our progress in understanding brain mechanisms forms the basis of neuroscientific applications. This group has contributed to the development of fMRI neurofeedback and fMRI-based brain computer interfaces (BCI) and is further reducing methodological and conceptual limitations by improving artifact control, sensitivity, real-time algorithms, and experimental designs. Physiological self-regulation of the local BOLD response has become a new paradigm for cognitive neuroscience to study brain plasticity and the functional relevance of regulated brain areas by modification of behaviour. Voluntary control of (abnormal) activity in circumscribed brain areas may even be applied as a therapeutic tool. Furthermore, fMRI-based BCIs might constitute an alternative approach for brain-based communication in severely motor-impaired so-called ‘locked-in’ patients.
Computational Brain Connectivity led by: Alard Roebroeck
The CBC lab's research focusses on the human brain, investigating both its structure and function. In both aspects the emphasis is on intrincately connected circuits in the human cortex, and how they support computations that enable human perceptual and cognitive capabilities. The adult human brain consists of about 80 billion neurons, each of them making, on average, 10 to 20 thousand connections to other neurons. No other organ is so densely and intricately connected as the brain. Much is still unknown about how the complex circuits formed by these connections support the communication of activity between neurons and, ultimately, the computations the brain can perform. In the CBC lab we use state-of-the-art 3D imaging methods to measure the connectivity in brain circuits at different spatial scales. We then model the activity and computations these circuits might support and relate these to measurements of human brain activity. We have a strong methods development component and develop hardware and software technology. We use this technology to answer basic and applied questions about human brain circuits and computations, such as:
- How is layered cortical architecture (cell size and density, axon density and myelination) related to cortical microcircuits?
- How does cortical connectivity at multiple spatial scales enable cortical circuit computations needed for perception and cognition?
- How does the breakdown of neurons and connections in neurodegenerative diseases such as Alzheimer’s disease lead to loss of function and even people’s very personality?
The main research topics in the CBClab are:
- Cortical layering and microcircuit connectivity
- White matter microstructure
- The human connectome
- Causal interactions of brain regions
For more information about the research and publications in the CBClab, please visit www.cbclab.org.