Dr Chen Song

COFUND Fellow

Research group:
Neuroscience
Email:
SongC5@cardiff.ac.uk
Telephone:
029 206 88910
Location:
CUBRIC, Maindy Road

Research summary

Brain Complexity - Organizing Principles of the Brain

Our brain is highly complex and is composed of many regions, each serving a unique set of functions. What enables different brain regions to have different functions? Is that because of their inherent structural differences? If so, how do structurally different brain regions get to work coordinately? To understand the organizing principles of the brain, we study (A) how different brain regions differ structurally, (B) how the structural differences underlie the functional differences, and (C) whether the empirically observed function of a brain region is indeed what the structure of this region is most optimal for.

From Brain Complexity to Behavioral Complexity - Variability across Individuals

Mirroring the brain complexity, our behavior and consciousness are highly complex. For example, our perception of an image is rarely a truthful reflection of the physical features of the image, but is instead biased by the contexts in which the image appears, and our susceptibility to such contextual illusions can vary over ten folds across healthy individuals. How does behavioral complexity relate to brain complexity? What brain properties give rise to the variability in conscious experiences across individuals? To understand the links between brain and consciousness, we study (A) how different individuals differ in their brain structure, (B) how the inter-individual differences in brain structure affect neural function, and (C) lead to inter-individual differences in behavior and consciousness.

Brain and Behavioral Plasticity - Impacts of Learning and Sleep

Our behavior exhibits high adaptability and plasticity, and so is our brain. The changes in brain structure not only occur when we are awake and learning, but also continue as we fall asleep. To understand the mechanisms of brain and behavioral plasticity, we study (A) how learning and sleep interact to influence brain and behavior, (B) whether different mechanisms of brain plasticity may be at play during wake versus sleep, and (C) whether the contrast between wake and sleep in brain plasticity may hold key to our behavioral plasticity and our ability to constantly learn and adapt.

Please visit my website BRAIN COMPLEXITY & CONSCIOUSNESS for details of projects, publications, and funding.

Teaching summary

I give guest lecture on MSc in Neuroimaging Module Perception and Action (PST507).

Selected publications (2014 onwards)

 

Full list of publications

 

Media activities

content

Research topics and related papers

Brain Complexity - Organizing Principles of the Brain

Aims: Our brain is highly complex and is composed of interconnected brain regions. The interconnected nature of the brain poses great challenges for studying brain function. In essence, the activation of a brain region in a cognitive task is driven by all regions that this region connects with, and it is difficult to tell which ones of these regions, or all of them, are responsible for this cognitive task. Thus, looking at brain activity alone is not enough for understanding brain function. We take a different approach, looking at what enables different brain regions to have different functions at first place - their structural differences. We study how different brain regions differ structurally and how their structural differences underlie their functional differences.

Progress: Our research reveals a systematic structural difference between sensory cortices and prefrontal cortex. We found that sensory cortices have topographically ordered wiring, high information capacity, but low flexibility; by contrast, frontal cortex has random wiring, low information capacity, but high flexibility. These structural differences match their functional differences: the high information capacity of sensory cortices is well suited for uni-sensory processing and multisensory integration, whereas the high flexibility of prefrontal cortex is well suited for executive control. Our research also reveals a reverse correlation between the sizes of sensory cortices and prefrontal cortex. We found that individuals with large sensory cortices have small prefrontal cortex, and vice versa. This structural trade-off challenges the traditional view that the sizes of different brain regions simply scale with the overall brain size, and hints towards a functional trade-off between low-level sensory domains and high-level cognitive domains.

From Brain Complexity to Behavioral Complexity - Variability across Individuals

Aims: Mirroring the brain complexity, human behavior and conscious experiences exhibit high complexity. The complexity is present not only in high-level cognitive domains such as introspection, planning, reasoning, but also in low-level sensory domains. For example, our perception of an image is rarely a truthful reflection of the physical features of the image, but is instead biased by the contexts in which the image appears and by our experience or expectation. How does behavioral complexity relate to brain complexity? Research on brain-behavior relationships often focuses on the similarity across individuals in brain and behavior. We instead take the opposite approach, studying how individual differences in brain complexity relate to individual differences in behavioral complexity.

Progress: Our research reveals that a behaviorally advantageous visual cortex has the structure of a large surface area but a small thickness. We found that individuals with larger visual cortex can discriminate finer visual details and experience weaker visual illusions; by contrast, thicker visual cortex is associated with poorer vision. Critically, we found that the impacts of brain structure on visual perception are mirrored in neural function: neurons in larger or thinner visual cortex have more precise coding. To explain our findings, we built a computational model of visual cortex. The model suggests that enlarging the cortical surface area increases the number of cortical units, whereas shortening the cortical thickness decreases the processing delays within cortical units; either way, the structure supports higher functionality. The model predicts correlations between visual perception and intrinsic connectivity, oscillation frequency, or neurotransmitter level of visual cortex, which we tested and all confirmed.

Brain and Behavioral Plasticity - Impacts of Learning and Sleep

Aims: A remarkable feature of human brain and behavior is their adaptability and plasticity. The environmental inputs we receive while awake can induce changes in brain and behavior, via which we learn and adapt. Even when we are asleep and disconnected from the environment, the brain is still highly active, and the sleeping brain activity can induce brain structural changes via activity-dependent plasticity. Research on brain plasticity often focuses on the net changes across the sleep-wake cycle. We instead suggest that opposite mechanisms of brain plasticity may be at play during wake versus sleep, and the contrast between wake and sleep in brain plasticity may hold key to our behavioral plasticity and our ability to constantly learn and adapt.

Progress: We are currently testing how the brain structure and function change across the sleep-wake cycle, and whether these changes can account for the declines in behavioral performances with the time awake and the improvements in behavioral performances after sleep. While awake, the brain is constantly perturbed by inputs from the environment, which often induce activities incongruent with the brain's wiring. By contrast, during sleep, the brain is driven by itself, and its activity is congruent with its wiring. We hypothesize that the environmental-driven nature of waking brain activity will add noise to the brain's wiring and impair its efficiency, whereas the self-driven nature of sleeping brain activity will help to reinstate the wiring efficiency. We are also testing how learning and sleep interact to change brain structure and function. We hypothesize that, if the learning is ecologically beneficial and improves the brain’s wiring efficiency, it will get consolidated after sleep, and if not, it will be weakened by sleep.

Funding

8. Influence of Sleep on Human Brain Structure
Funding: Wellcome Trust
Institute: Cardiff University Brain Research Imaging Centre
Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison
Amount: £250,000
Duration: 03/2018-02/2022

7. Improving Human Cognition and Brain Structure by Manipulating Sleep Brain Activity
Funding: European Commission, Welsh Government, Cardiff University
Institute: Cardiff University Brain Research Imaging Centre
Amount: £360,694
Duration: 09/2017-08/2020

6. Dynamics of Solar Coronal Activity versus Human Brain Activity
Funding: University College London
Institute: Mullard Space Science Laboratory, University College London
Amount: £36,976
Duration: 09/2013-08/2015

5. Predicting Aesthetic Preferences from Human Brain Structure
Funding: University College London
Institute: Centre for Entrepreneurship and Business Interaction, University College London
Amount: £4,000
Duration: 09/2013-12/2013

4. Neural Basis of Individual Differences in Visual Perception
Funding: University College London
Institute: Institute of Cognitive Neuroscience, University College London
Amount: £54,985
Duration: 09/2010-08/2013

3. Context, Consciousness and the Brain
Funding: Brain Research Trust
Institute: Wellcome Trust Centre for Neuroimaging, University College London
Amount: £109,828
Duration: 09/2010-08/2013

2. Binocular Rivalry and Visual Consciousness
Funding: Sigma-Xi Society
Institute: Institute of Neuroscience, Chinese Academy of Sciences
Amount: $600
Duration: 07/2008-06/2009

1. Modelling Top-down Influences in Visual Processing
Funding: German Academic Exchange Service
Institute: Max Plank Institute for Mathematics in the Sciences
Amount: €2,400
Duration: 07/2007-10/2007

Research group

Neuroscience

External collaborators

Prof. Geraint Rees, Wellcome Trust Centre for Neuroimaging, University College London, UK.
Prof. Giulio Tononi, Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison, USA.
Prof. Haishan Yao, Institute of Neuroscience, Chinese Academy of Sciences, China.
Prof. Haidong Lu, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China.
Prof. Juergen Jost, Max Plank Institute for Mathematics in the Sciences, Germany.
Dr. Ryota Kanai, Sackler Centre for Consciousness Science, Sussex University, UK.
Dr. Melanie Boly, Department of Neurology, University of Wisconsin-Madison, USA.
Dr. Tobias Elze, Schepens Eye Research Institute, Harvard University, USA.

Postgraduate research interests

If you are interested in applying for a PhD, or for further information regarding my postgraduate research, please contact me directly (contact details available on the 'Overview' page), or submit a formal application here.

The joy of science lies very much in the collaboration between the like-minded, and the debate among the different-minded. We welcome anyone interested in our research to join or collaborate. We have PhD funding for 2018/19 intake and will be advertising soon. Please feel free to contact me at SongC5@cardiff.ac.uk for any inquiry, or visit my website BRAIN COMPLEXITY & CONSCIOUSNESS for details of projects, publications, and funding.

Education

PhD in Neuroscience, University College London
MSc in Cognitive Neuroscience, University College London
BSc in Biomedical Engineering, Shanghai Jiao Tong University

Positions

2017 - Present: Cardiff University Brain Research Imaging Centre, Cardiff University, UK.
2015 - 2017: Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison, USA
2013 - 2015: Mullard Space Science Laboratory, University College London, UK
2009 - 2013: Wellcome Trust Centre for Neuroimaging, University College London, UK
2009 - 2013: Institute of Cognitive Neuroscience, University College London, UK
2007 - 2007: Max Planck Institute for Mathematics in the Science, Germany
2006 - 2009: Institute of Neuroscience, Chinese Academy of Sciences, China

Awards

2017: Sir Henry Wellcome Fellowship, by Wellcome Trust
2017: Marie Curie COFUND Fellowship, by European Commission and Welsh Government
2016: British Neuroscience Association Award, by British Neuroscience Association
2015: Chinese Government Award for Outstanding Scholars Abroad, by Chinese Government
2014: Engineering Young Entrepreneurs Scheme Award, by EPSRC
2013: Cross-disciplinary Research Scholarship, by University College London
2012: Enterprise Scholarship, by University College London
2010: Overseas Research Scholarship, by University College London
2010: Brain Research Trust Scholarship, by Brain Research Trust
2008: Sigma Xi Grants-in-Aid of Research Award, by Sigma Xi Society
2007: DAAD-IAESTE Award, by German Academic Exchange Service
2006: Excellent Academy Scholarship, by Shanghai Jiao Tong University
2005: National Scholarship, by Chinese Government