Tag Archives: brain

Human Brain Parts and Regions

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Last update : October 11, 2014

human brain regions

brain regions

The brain is the center of the nervous system in all vertebrate and most invertebrate animals. From a philosophical point of view, what makes the brain special in comparison to other organs is that it forms the physical structure that generates the mind. Through much of history, the mind was thought to be separate from the brain. Even for present-day neuroscience, the mechanisms by which human brain activity gives rise to consciousness and thought remain very challenging to understand: despite rapid scientific progress, much about how the human brain works remains a mystery. The operations of individual brain cells are now understood in considerable detail, but the way they cooperate in ensembles of millions has been very difficult to decipher.

The human brain has three main parts :

  1. The cerebrum, or telencephalon (Grosshirn, cerveau), that fills up most of the skull, is involved in cognition and also controls movement.
  2. The cerebellum, or little brain (Kleinhirn, cervelet), that sits at the back of the head, under the cerebrum, controls coordination and balance.
  3. The brainstem (Hirnstamm, tronc cérébral), that sits beneath the cerebrum in front of the cerebellum, connects the brain to the spinal cord and controls automatic functions such as breathing, digestion, heart rate and blood pressure.

The human brain is divided into right and left halves (hemispheres). The left half controls movement on the body’s right side. The right half controls the body’s left side. In most people, the language area is mainly on the left. Preserved brains have a grey color, hence the name grey matter.

The brain’s wrinkled surface is a specialized outer layer of the cerebrum, called the cerebral cortex (what we see when we look at the brain). Each bump on the surface of the human brain is known as a gyrus, while each groove is known as a sulcus.

In a typical human the cerebral cortex is estimated to contain 15–33 billion neurons, each connected by synapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells..

Traditionally the cerebral cortex is divided into four sections, which are known as lobes :

english latin deutsch français
Frontal Lobe Lobus frontalis Stirnlappen lobe frontal
Parietal lobe Lobus parietalis Scheitellappen lobe pariétal
Temporal lobe Lobus temporalis Schläfenlappen lobe temporal
Occipital lobe Lobus occipitalis Hinterhauptlappen lobe occipital

The Terminologia Anatomica (TA), the international standard on human anatomic terminology, developed by the Federative Committee on Anatomical Terminology (FCAT) and the International Federation of Associations of Anatomists (IFAA), released in 1998, defines two additional lobes : The limbic lobe, associated to emotion and memory and the insular cortex, associated to pain and some other senses.

The frontal lobe is associated with reasoning, motor skills, higher level cognition, and expressive language. The parietal lobe is associated with processing tactile sensory information such as pressure, touch, and pain. The temporal lobe is the location of the primary auditory cortex, which is important for interpreting sounds and the language we hear. The hippocampus is also located in the temporal lobe, which is why this portion of the brain is heavily associated with the formation of memories. The occipital lobe is associated with interpreting visual stimuli and information. The primary visual cortex, which receives and interprets information from the retinas of the eyes, is located in the occipital lobe.

The cerebral cortex is also segmented in cortical areas which are functionally or anatomically defined. Some examples are listed below :

human brain areas

brain areas

The brainstem is comprised of the hindbrain (rhombencephalon) and midbrain. The hindbrain contains structures including medulla oblongata, the pons and the reticular formation.

The limbic system contains glands which help relay emotions. Many hormonal responses that the body generates are initiated in this area. The limbic system includes the amygdala, hippocampus, hypothalamus and thalamus.

Great progresses in the analysis which parts of the brain are involved in a particular mental process have been made in the last years with the functional magnetic resonance imaging (fMRI).

More informations about human brain parts and regions are available at the following links:

at Wikipedia :

other sources :

Biological and artificial neurons

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Biological neurons

A biological neuron (nerve cell) is an electrically excitable cell that processes and transmits information through electrical and chemical signals. A chemical signal occurs via a synapse, a specialized connection with other cells. Neurons connect to each other to form neural networks. Neurons are the core components of the nervous system, which includes the brain, spinal cord, and peripheral ganglia. There are different types of neurons: sensory neurons, motor neurons and interneurons.

A typical neuron possesses a soma (perkaryon or cyton = cell body with nucleus), dendrites and an axon. Neurons do not undergo cell division.

Neurons

Neuron (Wikipedia)

Dendrites are thin structures that arise from the cell body, branching multiple times and giving rise to a complex dendritic tree. An axon is a special cellular extension that arises from the cell body and travels for long distances (as far as 1 meter in humans). The cell body of a neuron gives rise to multiple dendrites, but never to more than one axon, although the axon may branch hundreds of times before it terminates. The axon terminal contains synapses, specialized structures where neurotransmitter chemicals are released to communicate with target neurons. At the majority of synapses, signals are sent from the axon of one neuron to a dendrite of another, however there are a lot of exceptions.

All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion (sodium, potassium, chloride, calcium) pumps. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. Each time the electrical potential inside the soma reaches a certain threshold, an all-or-none electrochemical pulse called an action potential is fired, which travels rapidly along the cell’s axon, and activates synaptic connections with other cells when it arrives.

Artificial neurons

An artificial neuron is a mathematical function conceived as an abstraction of biological neurons. The artificial neuron receives one or more inputs (representing the dendrites) and sums them to produce an output (representing the axon). Usually the sums of each node are weighted, and the sum is passed through a non-linear function known as an activation function or transfer function.

The first artificial neuron was the Threshold Logic Unit (TLU) first proposed by Warren McCulloch and Walter Pitts in 1943. This model is still the standard of reference in the field of neural networks and called a McCulloch–Pitts neuron. However, artificial neurons of simple types, such as the McCulloch–Pitts model, are sometimes characterized as caricature models, in that they are intended to reflect one or more neurophysiological observations, but without regard to realism.

In the 1980s computer scientist Carver Mead, who is widely regarded as the father of neuromorphic computing, demonstrated that sub-threshold CMOS circuits behave in a similar way to the ion-channel proteins in cell membranes. Ion channels, which shuttle electrically charged sodium and potassium atoms into and out of cells, are responsible for creating action potentials. Using sub-threshold domains mimicks action potentials with little power consumption.

At the Neuromorphic Cognitive Systems Institute of Neuroinformatics of the University of Zurich and ETH Zurich, a research group leaded by Giacomo Indiveri is currently developing, using the sub-threshold-domain principle, neuromorphic chips that have hundreds of artificial neurons and thousands of synapses between those neurons.

OpenWorm Caenorhabditis elegans

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Last update : September 4, 2024

OpenWorm aims to build the first comprehensive computational model of the Caenorhabditis elegans (often called C. elegans, even if this term is a species abbreviation), a free-living, transparent nematode (roundworm), about 1 mm in length, that lives in temperate soil environments. With only a thousand cells, it solves basic problems such as feeding, mate-finding and predator avoidance.

OpenWorm background

Research into the molecular and developmental biology of C. elegans was begun in 1974 by Nobel prize laureate Sydney Brenner and it has since been used extensively as a model organism for development biology. Sydney Brenner founded the Molecular Sciences Institute in Berkeley, California.

Caenorhabditis elegans (Wikipedia)

Caenorhabditis elegans (Wikipedia)

The basic anatomy of C. elegans includes a mouth, pharynx, intestine, gonad, and collagenous cuticle. C. elegans has two sexes: hermaphrodites and males (0.05%).

C. elegans is one of the simplest organisms with a nervous system. In the hermaphrodite, this comprises 302 neurons whose pattern of connectivity (connectome) has been completely mapped and shown to be a small-world network. C. elegans was also the first multicellular organism to have its genome completely sequenced. The genome consists of six chromosomes (named I, II, III, IV, V and X) and a mitochondrial genome. The sequence was first published in 1998 with regular updates, because DNA sequencing is not an error-free process. The latest version released in the WormBase () is WS238.

WormBase is an international consortium of biologists and computer scientists dedicated to providing the research community with accurate, current, accessible information concerning the genetics, genomics and biology of C. elegans and related nematodes. Founded in 2000, the WormBase Consortium is led by Paul Sternberg of CalTech, Paul Kersey of the EBI, Matt Berriman of the Wellcome Trust Sanger Institute, Lincoln Stein of the Ontario Institute for Cancer Research, and John Spieth of the Washington University Genome Sequencing Center. Richard Durbin served as a principal investigator until 2010.

Additional informations about C. elegans are available at the following links :

  • WormBook – a free online compendium of all aspects of C. elegans biology
  • WormAtlas – an online database for behavioral and structural anatomy of C. elegans
  • WormClassroom – an education portal for C. elegans
  • WormImage – thousands of unpublished electron micrographs and associated data
  • WormWeb.org – an interactive cell lineage and neural network
  • Cell Exlorer – a 3D visualization tool for the structural anatomy of C. elegans
  • C. elegans movies

OpenWorm open source project

Despite being extremely well studied in biology, the C. elegans still eludes a deep, principled understanding of its biology. The OpenWorm project uses a bottom-up approach, aimed at observing the worm behaviour emerge from a simulation of data derived from scientific experiments carried out over the past decade. To do so, the data available in the scientific community is incorporated into OpenWorm software models.

An open-source simulation platform called Geppetto is used by the OpenWorm Project to run these different models together. An OpenWorm Browser enables ready access to a cell-by-cell 3D representation of the nematode C. elegans in a WebGL enabled browser. The 3d browser was created with the help of the Google Labs Body Browser team. The browser has also been ported to an iOS app to support the project. All the code produced in the OpenWorm project is Open Source and available on GitHub.

The OpenWorm project was realized by a highly motivated group of individuals who believe in Open Science.

The early core team members of the OpenWorm project were :

Bibliography

Neuromorphic computing

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neuromorphic computing by Spike Gerrell

credit : Spike Gerrell for the Economist

Neuromorphic computing is a concept developed by Carver Mead, describing the use of very-large-scale integration (VLSI) systems containing electronic analog circuits to mimic neuro-biological architectures present in the nervous system. Carver Mead is a key pioneer of modern microelectronics.

Today the term neuromorphic is used to describe analog, digital, and mixed-mode analog/digital VLSI and software systems that implement models of neural systems. Neuromorphic computing is a new interdisciplinary discipline that takes inspiration from biology, physics, mathematics, computer science and engineering to design artificial neural systems and autonomous robots, whose physical architecture and design principles are based on those of biological nervous systems.

The goal is to make computers more like brains and to design computers that have  features that brains have and computers do not have up to now :

  • low power consumption (human brains use about 20 watts)
  • fault tolerance (brains lose neurons all time without impact)
  • lack of need to be programmed (brains learn and change)

An important property of a real brain is that each neuron has tens of thousands of synaptic connections with other neurons, which form a sort of small-world network. Many neuromorphic chips use what is called a cross-bar architecture, a dense grid of wires, each of which is connected to a neuron at the periphery of the grid, to create this small-world network. Other chips employs what is called synaptic time multiplexing.

The Economist published a few days ago a great article “Neuromorphic computing – The machine of a new soul” with illustrations from the London-based illustrator Spike Gerrell.

Some neuromorphic computing reletad projects are listed below :

Neuromorphic computing is dominated by European researchers rather than American ones. The following links provide additional informations about neuromorphic computing related institutions and topics :

Functional magnetic resonance imaging (fMRI)

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Last update : August 7, 2013

Functional MRI (fMRI) is a magnetic resonance imaging procedure that measures brain activity by detecting associated changes in blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. Since the early 1990s, fMRI has come to dominate brain mapping research. The primary form of fMRI uses the blood-oxygen-level-dependent (BOLD) contrast discovered by Seiji Ogawa at the AT&T Bell labs.

fMRI is used both in the research world (cognitive neuroscience, cognitive psychology, neuropsychology, and social neuroscience), and to a lesser extent, in the clinical world.

Links to additional informations about fMRI and related topics are provided in the following list :

Parcellation of the brain : fRMI

Parcellation of the brain

The Gallant Lab provides free access to several publications, links to websites and tools of the lab and a WebGL brain viewer.

Pycortex WebGL fMRI brain viewer

Pycortex WebGL MRI brain viewer

The american Human Brain Activity Map Project

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Last update : August 10, 2013

Human Brain Activity Map Project

Cartoon by Jordan Adwan, The New Yorker, 2013

Several weeks after the public announcement of the Human Brain Project as a european research FET Flagship by the European Commission, the US administration unveiled the planning of a decade-long scientific effort to examine the workings of the human brain and build a comprehensive map of its activity, seeking to do for the brain what the Human Genome Project did for genetics. The project called Brain Activity Map (BAM) will include federal agencies, private foundations and teams of neuroscientists and nanoscientists in a concerted effort to advance the knowledge of the brain’s billions of neurons and gain greater insights into perception, actions and, ultimately, consciousness. Moreover, the project holds the potential of paving the way for advances in artificial intelligence.

The Human Brain Activity Map initiative will be organized by the Office of Science and Technology Policy (OSTP). Partners will be the National Institutes of Health (NIH), the Defense Advanced Research Projects Agency (DARPA), the National Science Foundation (NSF), the Howard Hughes Medical Institute (HHMI) in Chevy Chase, the Allen Institute for Brain Science in Seattle and other big actors as Google and Microsoft.

Gary Marcus, a professor at New York University (N.Y.U.), recommends to endow five separate projects rather than putting a huge amount of money into a single project. He proposes to address the most fundamental unsolved questions in neuroscience :

  • Decipher the basic language of the brain : What is the basic element of neural computation ? What is the basic scheme by which symbolic information (like sentences) are stored ?
  • Understand the rules governing how neurons organize into circuits
  • Determine which circuits to use in a given situation and understanding how the brain communicates information from one region to another (neural plasticity and neural development)
  • Find the relation between brain circuits, genes, and behavior
  • Develop new techniques for analyzing and observing brain function

The following list provides some links to additional informations about the Human Brain Activity Map Project :

Mammal and Human Brain Projects

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Last update : August 6, 2013

Human Brain Project (2013)

The Human Brain Project (HBP) was submitted on 23 October 2012 for funding under the European Union’s FET Flagship program. FET (Future & Emerging Technologies) flagships are ambitious large-scale, science-driven, research initiatives that aim to achieve a visionary goal. On January 28, 2013, the European Commission has officially announced the selection of the Human Brain Project as one of its two FET Flagship projects.

The goal of the HBP is to understand and mimic the way the human brain works. The Blue Brain Project’s success has demonstrated the feasibility of the HBP general strategy.

The project will be coordinated by the École Polytechnique Fédérale de Lausanne (EPFL) and will be hosted at the NEUROPOLIS platform. The HBP team will include many of Europe’s best neuroscientists, doctors, physicists, mathematicians, computer engineers and ethicists. The leaders of the different sub-groups are : Universidad Politécnica de Madrid, Forschungszentrum Jülich GmbH, CEA, Le Centre national de la recherche scientifique, Karolinska Institutet, Centre hospitalier universitaire vaudois, Universität Heidelberg, Technische Universität München, Institut Pasteur. In total more than 120 teams in 90 scientific institutions from 22 countries will contribute to the HBP. A full list of partners and collaborators is presented at the HBP website. The HBP will be open by involving groups and individual scientists who are not members of the original consortium.This will be handled by the HBP Competitive Calls Programme.

The Human Brain Project has the potential to revolutionize technology, medicine, neuroscience, and society. It will drive the development of new technologies for supercomputing and for scientific visualization. Models of the brain will allow us to design computers, robots, sensors and other devices far more powerful, more intelligent and more energy efficient than any we know today. Brain simulation will help us understand the root causes of brain diseases, to diagnose them early, to develop new treatments, and to reduce reliance on animal testing. The project will also throw new light on questions human beings have been asking for more than two and a half thousand years. What does it mean to perceive, to think, to remember, to learn, to know, to decide? What does it mean to be conscious?

A video of the HBP is available at the Vimeo website.

The HBP is organized in thirteen subprojects :

Blue Brain Project (2005)

The Blue Brain Project is an attempt to create a synthetic brain by reverse-engineering the mammalian brain down to the molecular level. The aim of the project, founded in May 2005 by the Brain and Mind Institute of the École Polytechnique Fédérale de Lausanne (EPFL), is to study the brain’s architectural and functional principles. The project is headed by the Institute’s director, Henry Markram.

Using an IBM Blue Gene supercomputer running Michael Hines‘s NEURON software, the simulation involves a biologically realistic model of neurons. There are numerous sub-projects run by universities and independent laboratories.

The current version 7.2 of NEURON is available as a cross-platform program under a GNU GPL licence from the universities Yale and Duke.

A ten-year documentary film-in-the-making about the race to reverse engineer the human brain is available at the Bluebrain Film website.

In the future the Blue Brain Project will be part of the Human Brain Project.

Brain Architecture Projects (2009)

The Brain Architecture Project is a collaborative effort aimed at creating an integrated resource containing knowledge about nervous system architecture in multiple species, with a focus on mouse and human. The Brain Architecture Project Principal Investigator is Partha P. Mitra, professor at the Cold Spring Harbor Laboratory (CSHL).

The goal of the Mouse Brain Architecture (MBA) Project is to generate brainwide maps of inter-regional neural connectivity. These maps will thus specify the inputs and outputs of every brain region, at a mesoscopic level of analysis corresponding to brain compartments defined in classical neuroanatomy.

The Human Brain Architecture Project includes several components related to the human brain : The Online Brain Atlas Reconciliation Tool (OBART), The Human Brain Connectivity Database and the Co-expression networks of genes related to addiction.

The Brain Architecture Team has also been working on two prototype systems (Text Mining) for information extraction (IE) of knowledge related to brain architecture from a large text corpus containing approximately 55,000 full-text journal articles.

Brain Reverse Engineering Lab (2011)

This project is headed by Witali L. Dunin-Barkowski, Head of the Department of Neuroinformatics at the Center for Optical Neural Technologies of the Scientific Research Institute for System Analysis of the Russian Academy of Sciences.

The main initial task of the laboratory will be the creation of open-access scientific, technological and engineering internet-resource in a form of a specialized database of knowledge on mechanisms of brain work. It is supposed that as a result of the planned work at the end of 2015 the project’s team will elaborate the full detailed description of the mechanisms of human brain. It will be possible to use this description to make in the following years a full scale working analog of the human brain, based on technological informational elements and devices.

Neuroscience and Neurobiology

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Last update : August 10, 2013

Neuroscience

Neurons “Blue Brain Project”

Neuroscience is the scientific study of the nervous system, mainly the brain. In the past neuroscience has been seen as a branch of biology. Today it is an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics, medicine, philosophy, physics, and psychology.

Recent theoretical advances in neuroscience have been aided by the study of neural networks.

Neurobiology is sometimes used as a synonym, although it refers specifically to the biology of the nervous system. Neurobiology is studied at numerous universities : Harvard, Stanford, Yale, UCLA, Duke, Austin, …

Several prominent neuroscience organizations have been formed to provide a forum to all neuroscientists :

A public education booklet about the brain and neuroscience has been published by the IBRO.

In June 2012, EPFL (Ecole Polytechnique Fédérale de Lausanne) launched the NEUROPOLIS project, a global Neuroscience Hub, with the partnership of the Universities of Lausanne and Geneva. Two entities will be constructed :

  • A research infrastructure in Lausanne, constructed on the grounds of the institutions of higher learning, UNIL-EPFL
  • A research infrastructure in Geneva, near the University Hospital, including a new Institute of Translational Molecular Imaging (UNIGE)

NEUROPOLIS will establish an institute of international stature. Like CERN in the field of physics, NEUROPOLIS unites neuroscientists and biologists from around the world. The initiator of the project is Henry Markram, the Director of the Human Brain Project at EPFL. NEUROPOLIS will also be open to the general public : an interactive space will be dedicated to neuroscience and the conquest of the brain. A video about the project is available at Dailymotion.

Another famous medical research organization, dedicated to accelerating the understanding of how the human brain works, is the Allen Institute for Brain Science. This Seattle-based nonprofit institute was launched in 2003 by Paul Allen, the co-founder, with Bill Gates, of Microsoft Corporation. The Allen Institute for Brain Science provides researchers and educators with a variety of unique online public resources for exploring the nervous system, which are all openly accessible via the Allen Brain Atlas data portal.

Additional informations about neuroscience and neurobiology are available at the following links :

Global Brain Metaphor

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Last update : August 6, 2013

Global Brain

Global Brain Project

The global brain is a metaphor for the worldwide intelligent network formed by all the individuals of this planet, together with the information and communication technologies that connect them into a self-organizing whole. Although the underlying ideas are much older, the term was coined in 1982 by Peter Russell in his book The Global Brain.

The first peer-refereed article on the subject was written by Gottfried Mayer-Kress and Cathleen Barczys in 1995. The first algorithms that could turn the world-wide web into a collectively intelligent network were proposed by Francis Heylighen and Johan Bollen in 1996. Francis Heylighen reviewed the history of the concept and its usage, he distinguished four perspectives  :

  • organicism
  • encyclopedism
  • emergentism
  • evolutionary cybernetics

These perspectives now appear to come together into a single conception.

Global Brain Group and Institute

In 1996, Francis Heylighen and Ben Goertzel founded the Global Brain Group, a discussion forum grouping most of the researchers that had been working on the subject to further investigate this phenomenon. The group organized the first international conference on the topic in 2001. In January 2012, the Global Brain Institute (GBI) was founded at the Vrije Universiteit Brussel to develop a mathematical theory of the brainlike propagation of information across the Internet. The GBI grew out of the Global Brain Group and the Evolution, Complexity and Cognition research group (ECCO).

The following list provides links to further informations about the global brain :

Virtual Assistant Denise by Guile3D

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Last update : May 30, 2014

Virtual Assistant Denise

Guile 3D Denise

Guile 3D Studio, a company founded in 2001 by System Analyst, Artificial Intelligence Specialist and 3D Graphic Artist Guile Lindroth, created the advanced Virtual Assistant Denise. She comes with a real-time proprietary graphic engine, a high quality English Text to speech voice and a Voice Recognition engine. Denise works with an adaptive Artificial Intelligence Brain, based on AIML, that can learn by itself and be customized by user.

Denise was the winner of the Chatterbox Challenge 2011 in the category Best New Bot. In 2014 Denise was the winner of the 1st place in the Chatterbox Challenge..

In september 2011, Guile 3D teamed up with NeuroSky for a brainwave impulse control interface. The NeuroSky MindWave headset is the first product available for the consumer market. As a turnkey brainwave sensing headset, it uses the same bio-sensor as the Mattel MindFlex, Star Wars Force Trainer and NeuroSky’s research tool the MindSet. It measures brainwave impulses from the forehead from a position neuroscientists call FP1 with research grade precision.

In the same month, Guile 3D teamed up with EMOTIV for computer-brain control interface. Based on the latest developments in neuro-technology, Emotiv has developed a revolutionary new personal interface for human computer interaction.

In 2013 an Avatar Builder SDK was announced which was however never released up to now. In January 2014, Guile 3D Studio became NextOS. The company will now focus in the Home Automation area as well improve the Virtual Assistant Technology. In April 2014 NextOS stopped for a while the work on the desktop version Denise 2.0 to get the Home Automation and the mobile modules ready. Late May 2014, NextOS started an Alpha testing phase for Virtual Denise Mobile on iOS, Android and Windows Phone 8 platforms. For this purpose NextOS uses both TestFlight, a free platform to distribute beta and internal iOS applications to team members and .