This paper characterizes two distinct philosophies underlying previous work on how Bayesian computations are linked to neural data, highlighting how different theories may be motivated by different tacit assumptions and thereby explain different data.
Prof. Sakhrat Khizroev (University of Miami) discusses how new and advanced materials can be used for interfacing machines and the human brain!
#brain #machines #advancedmaterials
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In the grand theater of the cosmos, amidst a myriad of distant suns and ancient galaxies, the Fermi Paradox presents a haunting silence, where a cacophony of alien conversations should exist. Where is Everyone? Or are we alone?
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The Fermi Paradox Compendium of Solutions & Terms.
Episode 420; November 9, 2023
Written, Produced & Narrated by: Isaac Arthur.
Editors: Donagh Broderick.
Graphics by:
Darth Biomech.
Jeremy Jozwik.
Katie Byrne.
Ken York YD Visual.
Legiontech Studios.
Sergio Botero.
Tactical Blob.
Udo Schroeter.
Music Courtesy of:
Epidemic Sound http://epidemicsound.com/creator.
Markus Junnikkala, “Memory of Earth“
Stellardrone, “Red Giant”, “Ultra Deep Field“
Sergey Cheremisinov, “Labyrinth”, “Forgotten Stars“
Miguel Johnson, “The Explorers”, “Strange New World“
Aerium, “Fifth star of Aldebaran”, “Windmill Forests”, “Deiljocht“
Lombus, “Cosmic Soup“
Taras Harkavyi, “Alpha and…”
0:00:00 Intro.
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Is the Matrix really real? And if so, which pill would David Chalmers take?
Join us for a mind-bending journey through virtual worlds, human consciousness, technology, philosophy, and religion, and find out!
David Chalmers is an Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language. He is a Professor of Philosophy and Neural Science at New York University and co-director of NYU’s Center for Mind, Brain, and Consciousness (along with Ned Block).
Remastered from an interview in 2022
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Neuralink, the Elon Musk-founded company developing implantable chips that can read brain waves, has raised an additional $43 million in venture capital, according to a filing with the SEC.
The filing published this week shows the company increased its previous tranche, led by Peter Thiel’s Founders Fund, from $280 million to $323 million in early August. Thirty-two investors participated, according to the filing.
Neuralink hasn’t disclosed its valuation recently. But in June, Reuters reported that the company was valued at about $5 billion after privately-executed stock trades.
5th BigBrain Workshop 2021
22 September 2021 — Applications.
Chair: Kathleen Rockland.
The Unique Cytoarchitecture and Wiring of The Default Mode Network.
Casey Paquola.
Background. Complex behaviours benefit from parallel distributed processing in multiple brain networks. The roles of certain networks are well-defined, while others remain elusive. Arguably, none are so elusive as the default mode network (DMN); a distributed set of brain regions that decrease in activity during many externally oriented tasks. Revealing the cytoarchitectural composition and connectional layout of the DMN is crucial to defining its role in complex behaviours.
Method. We examined the cytoarchitectural composition of the DMN using an established cortical type atlas (García-Cabezas et al., 2020; Von Economo and Koskinas, 1925) and by applying non-linear dimensionality reduction to BigBrain-derived staining intensity profiles (Paquola et al., 2019). Next, we used magnetic resonance imaging (MRI) to explicate structural wiring and effective connectivity of the whole brain. In both modalities, we examined the influence of cytoarchitecture on extrinsic connectivity of the DMN. Finally, we evaluated the uniqueness of the DMN relative to other large-scale functional brain networks.
Results. We discovered profound diversity of DMN cytoarchitecture. Each circumscribed subregion of the DMN contains a broad range of cytoarchitectural types, however, the spatial pattern within each subregion differs. The patterns vary in smoothness from a gradient in the parahippocampus to interdigitation in the superior frontal gyrus. We found that cytoarchitectural differentiation in the DMN aligns with its structural wiring and extrinsic information flow. The structural heterogeneity of the DMN engenders a network-level balance in communication with external and internal sources, which is distinctive, relative to other functional networks.
Conclusion. These findings suggest a novel wiring diagram of structural and functional connectivity of the DMN that is compatible with its putative role in balancing internal and external information. Furthermore, our work demonstrates the import of neuroanatomical evidence in specifying theories of functional networks.
All information about the 5th BigBrain Workshop 2021, including detailed authors information: https://go.fzj.de/BigBrainWorkshop2021
An amazing graph theoretic analysis of the C. elegans neuropeptide connectome!
Neuromodulation by peptides is essential for brain function. By comprehensively mapping neuropeptide signaling in the nematode C. elegans, Ripoll-Sánchez et al. define a dense wireless network whose organization differs in important ways from wired brain circuits. This network is a prototype for understanding neuropeptide signaling networks in larger brains.
A study revealed that one-third of cardiac arrest survivors experienced consciousness, with EEG showing brain activity despite heart stoppage. This groundbreaking finding challenges current understandings of brain function during cardiac emergencies.
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My name is Artem, I’m a computational neuroscience student and researcher. In this video we discuss engrams – fundamental units of memory in the brain. We explore what engrams are, how memory is allocated, where it is stored, and how different memories become linked with each other.
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OUTLINE:
00:00 — Introduction.
00:39 — Historical background.
01:44 — Fear conditioning paradigm.
03:38 — Immediate-early genes as memory markers.
08:13 — Engrams are necessary and sufficient for recall.
10:16 — Excitabiliy and memory allocation.
16:19 — Brain-wide engrams.
18:12 — Linking memories together.
24:20 — Summary.
25:33 — Brilliant.
27:09 — Outro.
REFERENCES (in no particular order):
1. Robins, S. The 21st century engram. WIRES Cognitive Science e1653 (2023) doi:10.1002/wcs.1653.
2. Roy, D. S. et al. Brain-wide mapping reveals that engrams for a single memory are distributed across multiple brain regions. Nat Commun 13, 1799 (2022).
3. Josselyn, S. A. & Tonegawa, S. Memory engrams: Recalling the past and imagining the future. Science 367, eaaw4325 (2020).
4. Chen, L. et al. The role of intrinsic excitability in the evolution of memory: Significance in memory allocation, consolidation, and updating. Neurobiology of Learning and Memory 173, 107266 (2020).
5. Rao-Ruiz, P., Yu, J., Yu, J. J., Kushner, S. A. & Josselyn, S. A. Neuronal competition: microcircuit mechanisms define the sparsity of the engram. Current Opinion in Neurobiology 54163–170 (2019).
6. Josselyn, S. A. & Frankland, P. W. Memory Allocation: Mechanisms and Function. Annu. Rev. Neurosci. 41389–413 (2018).
7. Choi, J.-H. et al. Interregional synaptic maps among engram cells underlie memory formation. Science 360430–435 (2018).
8. Abdou, K. et al. Synapse-specific representation of the identity of overlapping memory engrams. Science 360, 1227–1231 (2018).
9. Yokose, J. et al. Overlapping memory trace indispensable for linking, but not recalling, individual memories. Science 355398–403 (2017).
10. Rashid, A. J. et al. Competition between engrams influences fear memory formation and recall. Science 353383–387 (2016).
11. Poo, M. et al. What is memory? The present state of the engram. BMC Biol 14, 40 (2016).
12. Park, S. et al. Neuronal Allocation to a Hippocampal Engram. Neuropsychopharmacol 41, 2987–2993 (2016).
13. Morrison, D. J. et al. Parvalbumin interneurons constrain the size of the lateral amygdala engram. Neurobiology of Learning and Memory 135, 91–99 (2016).
14. Minatohara, K., Akiyoshi, M. & Okuno, H. Role of Immediate-Early Genes in Synaptic Plasticity and Neuronal Ensembles Underlying the Memory Trace. Front. Mol. Neurosci. 8, (2016).
15. Josselyn, S. A., Köhler, S. & Frankland, P. W. Finding the engram. Nat Rev Neurosci 16521–534 (2015).
16. Yiu, A. P. et al. Neurons Are Recruited to a Memory Trace Based on Relative Neuronal Excitability Immediately before Training. Neuron 83722–735 (2014).
17. Redondo, R. L. et al. Bidirectional switch of the valence associated with a hippocampal contextual memory engram. Nature 513426–430 (2014).
18. Ramirez, S. et al. Creating a False Memory in the Hippocampus. Science 341387–391 (2013).
19. Liu, X. et al. Optogenetic stimulation of a hippocampal engram activates fear memory recall. Nature 484381–385 (2012).
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CREDITS:
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Georgetown University Medical Center neuroscientists revealed that the fusiform face area, a vital region for face processing in sighted people, plays an important role in helping blind people recognize faces.
