The research suggests that it is not size alone that gives more brain power, but that, during evolution, increasingly sophisticated molecular processing of nerve impulses allowed development of animals with more complex behaviours.

I artiklen Origins of the brain: Complex synapses drove brain evolution bliver vi fortalt om en forståelse af hvordan vores hjerne har udviklet sig og hvilke elementer der gør at hjerneaktivitet har den komplekse virke, som den har

Current thinking suggests that the protein components of nerve connections - called synapses - are similar in most animals from humble worms to humans and that it is increase in the number of synapses in larger animals that allows more sophisticated thought.

"Our simple view that 'more nerves' is sufficient to explain 'more brain power' is simply not supported by our study," explained Professor Seth Grant, Head of the Genes to Cognition Programme at the Wellcome Trust Sanger Institute and leader of the project. "Although many studies have looked at the number of neurons, none has looked at the molecular composition of neuron connections. We found dramatic differences in the numbers of proteins in the neuron connections between different species".

Forsøget indikere at synapsernes virke og opbygning har en væsentligt rolle i forhold til udviklingen af hjernen og dens funktion. Og at det således ikke alene afhænger af størrelsen på hjernen i helhed.

"We studied around 600 proteins that are found in mammalian synapses and were surprised to find that only 50 percent of these are also found in invertebrate synapses, and about 25 percent are in single-cell animals, which obviously don't have a brain."

Synapses are the junctions between nerves where electrical signals from one cell are transferred through a series of biochemical switches to the next. However, synapses are not simply soldered joints, but mini-processors that give the nervous systems the property of learning and memory.

Remarkably, the study shows that some of the proteins involved in synapse signalling and learning and memory are found in yeast, where they act to respond to signals from their environment, such as stress due to limited food or temperature change.
...
Simple invertebrate species have a set of simple forms of learning powered by molecularly simple synapses, and the complex mammalian species show a wider range of types of learning powered by molecularly very complex synapses.

"It is amazing how a process of Darwinian evolution by tinkering and improvement has generated, from a collection of sensory proteins in yeast, the complex synapse of mammals associated with learning and cognition," said Dr Richard Emes, Lecturer in Bioinformatics at Keele University, and joint first author on the paper.

The new findings will be important in understanding normal functioning of the human brain and will be directly relevant to disease studies. Professor Grant's team have identified recently evolved genes involved in impaired human cognition and modelled those deficits in the mouse.

"This work leads to a new and simple model for understanding the origins and diversity of brains and behaviour in all species" says Professor Grant, adding that "we are one step closer to understanding the logic behind the complexity of human brains"

I artiklen What Dictionaries and Optical Illusions Say About Our Brains bliver vi introduceret til den kognitive forsker Mark Changizi og hans tilgang til at forstå forskelligle aspekter af vores hjerne bedre. Han mener for at kunne gøre det må vi prøve at forstå hvorfor de forskellige mekanismer er udviklet i første omgang.

Although many neuroscientists are trying to figure out how the brain works, Mark Changizi is bent on determining why it works that way. In the past, the assistant professor of cognitive science at Rensselaer Polytechnic Institute has demonstrated that the shapes of letters in 100 writing systems reflect common ones seen in nature: Take the letter "A"—it looks like a mountain, he says. And "Y" might remind one of a tree with branches. He also showed that across different languages most characters take three strokes to write out. That's because, he says, three is the highest quantity a person's brain can perceive without resorting to counting. But Changizi's theories aren't limited to writing. He also believes that primates developed the ability to see in color so that they could figure out if peers were sending emotional cues. He hatched that theory by comparing the light wavelengths given off by the facial skin of someone blushing to that of a person not flushed.
...
My goal is to understand the principles underlying the design of the brain or visual system or cultural artifact, like language or writing systems. I'm not as interested in the mechanisms per se. People like me make the point that you can't even study those mechanisms without having an idea what those mechanisms are trying to compute. So you have to have some opinion about what the design or function of those mechanisms are for to even do that. So, I am focusing on the function from a teleological [purposive] point of view. Of course it's unpacked with natural selection or cultural evolution. 

 
Tankelæsning igen - hvordan ord aktiverer hjernen

I artiklerne Computer Model Reveals How Brain Represents Meaning og A computer that can 'read' your mind bliver der redegjort for nogle nylige undersøgelser i at prøve at forstå hvordan hjernen bliver aktiveret på baggrund af forskellige ord, ved en beregnet sandsynlighed og fMRI-skanninger.

Scientists at Carnegie Mellon University have taken an important step toward understanding how the human brain codes the meanings of words by creating the first computational model that can predict the unique brain activation patterns associated with names for things that you can see, hear, feel, taste or smell.´
...
The team, led by computer scientist Tom M. Mitchell and cognitive neuroscientist Marcel Just, constructed the computational model by using fMRI activation patterns for 60 concrete nouns and by statistically analyzing a set of texts totaling more than a trillion words, called a text corpus. The computer model combines this information about how words are used in text to predict the activation patterns for thousands of concrete nouns contained in the text corpus with accuracies significantly greater than chance.
...
Just, a professor of psychology who directs the Center for Cognitive Brain Imaging, said the computational model provides insight into the nature of human thought. "We are fundamentally perceivers and actors," he said. "So the brain represents the meaning of a concrete noun in areas of the brain associated with how people sense it or manipulate it. The meaning of an apple, for instance, is represented in brain areas responsible for tasting, for smelling, for chewing. An apple is what you do with it. Our work is a small but important step in breaking the brain's code."

Relaterede artikler Computer model reveals how brain represents meaning, Brain Imaging Shows If You Are Thinking Of Familiar Object, New Insights Into The Dynamics Of The Brain's Cortex.

About 30 million people around the world have grown legally blind due to retinal diseases. The EPI-RET project has sought for a technical solution for the past twelve years to help these patients. This work has resulted in a unique system – a fully implantable visual prosthesis.
...
A milestone was reached when the prosthetic system finally operated wirelessly and remotely controlled,” explains Dr. Ingo Krisch. “A great deal of detailed work was necessary before the implant could be activated without any external cable connections.”

“The designs became smaller and smaller, the materials more flexible, more robust and higher in performance, so that the implant now fits comfortably in the eye,” reports Michael Görtz. The system benefits from a particular disease pattern, and it uses a specific operating principle to restore sight: Suffering from retinitis pigmentosa, the light sensitive cells are destroyed, but the connection of the nerve cells to the brain remains intact.

The scientists have bypassed the defects of the retina by means of a visual prosthesis. The complete system comprises the implant and an external transmitter integrated in a spectacle-frame. The implant system converts the image patterns into interpretable stimulation signals. Data and energy are transferred to the implant by a telemetric link. The nerve cells inside the eye are then stimulated according to the captured images. Those intact cells are innervated by means of three-dimensional stimulation electrodes that rest against the retina like small studs.

Andre relevante artikler: Restoring Sight, One Pixel At A Time, Researchers Begin Tests On Next Generation Of Retinal Implant, Long-term Retinal Implant Study Offers Hope For Treating Blindness, Vision Partially Restored In Blind Mice.

Stamceller kan bruges i udbedringen af hjerneskader
 
I et andet område finder vi i artiklen New Stem Cell Therapy May Aid The Repair Of Damaged Brains. Stamceller menes at kunne blive brugt i mange forskellige sammenhænge, hvis vi altså formår at kontrollere udviklingen i cellerne.

According to some experts, newly born neuronal stem cells in the adult brain may provide a therapy for brain injury. But if these stem cells are to be utilized in this way, the process by which they are created, neurogenesis, must be regulated.
...
According to the research, neurogenesis can be regulated through induced hypothermia. In rat subjects, a mild decrease in body temperature was found to substantially decrease the proliferation of newly-born neurons, a discovery that marks a major step forward for the development of neuronal stem cell-based brain therapies.

Since the 1930s, brain damage from stroke, head injury, near drowning and cardiac arrest was considered to be permanent because of a lack of repair mechanisms like other parts of the body. However, discovery of neuronal stem cells in the adult brain challenges that belief.

“Many questions remain before we adequately understand how to control these cells to repair a damaged brain,” says Katz. “However, the findings represent an important step in demonstrating that these cells can be controlled by simple external forces like hypothermia.”

Andre relevante artikler: Stem-cell Therapies For Brain More Complicated Than Thought, Stem Cell Treatment Succeeds In Spinal Cord-injured Rats

Tankelæsning ved algoritmer

Forskere er meget uenige om hvilke udsigter der er til en eventuel tankelæsning. Og argumenterne for og imod beror på forskellige elementer; nogen mener ikke det vil være til at måle, andre mener godt det vil være til at måle, men er skeptisk i forhold til om vi kan udvikle teknologi til at gøre det. I mellemtiden forsker nogen i det. I Neuroscientists Take Important Step toward Mind Reading har vi en indgangsvinkel til det.

Neuroscientist Kendrick Kay and his colleagues at the University of California, Berkeley, were able to successfully determine which of a large group of never-before-seen photographs a subject was viewing based purely on functional MRI data. By analyzing fMRI scans of viewers as they looked at thousands of images, Kay’s team created a computer model that uses picture elements such as angles and brightness to predict the neural activity elicited by a novel black-and-white photograph. Then the researchers scanned subjects while showing them new snapshots. Most of the time Kay’s model could single out which image the subject was viewing by matching its prediction of brain activity to the actual activity measured by the fMRI scanner, although very similar pictures tended to baffle the program.
...
As for truly reading people’s thoughts, Kay does not foresee anything of that nature in this century. Technological improvement, he explains, may yield piles of brain data. Without sufficient insight into the brain’s workings, however, we will have no idea what it all means.

In our brains, where millions of signals move across a network of neurons like runners in a relay race, all the critical baton passes take place at synapses. These small gaps between nerve cell endings have to be just the right size for messages to transmit properly. Synapses that grow too large or too small are associated with motor and cognitive impairment, learning and memory difficulties, and other neurological disorders.

In a finding that sheds light on this system, researchers at the University of Wisconsin-Madison describe a gene that controls the proper development of synapses, which could help explain how the process works and why it sometimes goes wrong.

Reporting today in the journal Neuron, a team of geneticists in the College of Agricultural and Life Sciences reveal the role of a gene in fruit flies called "nervous wreck" that prevents synapses from overgrowing by damping the effects of a pro-growth signal. Mutations in a human version of "nervous wreck" have been linked to a severe genetic developmental disability, and these findings may eventually help scientists develop treatments for this and other neurological disorders.

De neurologiske abnormiteter kan selvfølgelig variere i styrke og i hvilken slags indflydelse de har på folk, men selv de mindste forhold kan have store implikationer. I en tidligere artikel, som jeg har referet til her, mente nogen at have fundet en sammenhæng mellem netop en neurologisk abnormitet og social fobi. Der var der fokus på et decideret misforhold i neurotransmittere, der er essentielle for at videreføre informationerne i hjernen . I den herværende artikel er der dog fokus på mere generelle forhold i synapserne , der er bindingsledene i kommunikationen i hjernen. Genetiske forhold menes at kunne være afgørende for om synapserne fx bliver for små eller for store.

Using genetic, biochemical and imaging techniques, O'Connor-Giles showed that the "nervous wreck" protein appears to be part of an important protein complex that helps regulate the density of certain receptors on the surface of the nerve cell at the synapse. In particular, the new findings suggest that the protein complex decommissions receptors that respond to pro-growth signals coming from the well-studied BMP signaling pathway. When the protein complex is working properly, it moves the receptors back inside the nerve cell - where they can no longer receive and respond to the pro-growth signal - at the appropriate time.

"'Nervous wreck' and (the other proteins in the complex) work together to attenuate a positive growth signal," says O'Connor-Giles. "So when it's time for synaptic growth to stop, they are the proteins that ensure the neuron stops listening to the positive growth signal and stops growing.

Undersøgelsen giver et indblik i forståelsen mellem forholdene mellem forskellige proteiner, celler og udviklingen og stabiliseringen af synapserne. Og igen er spørgsmålet om hvorvidt disse fremskridt i viden om forskellige neurologiske omstændigheder i sygdomme vil afføde behandlingsformer.

These findings add to the big picture of how synaptic growth works, a picture that in the long run will help scientists develop treatments for various neurological disorders.

"Being able to manipulate synaptic growth is going to be crucial for treating traumatic spinal chord injuries," says O'Connor-Giles. "It's also going to be important for treating a broad array of other disorders, including epilepsy and developmental disabilities."

Kilde:
University of Wisconsin-Madison (2008, May 25). At The Synapse: Gene May Shed Light On Neurological Disorders. ScienceDaily. Retrieved May 25, 2008, from http://www.sciencedaily.com/releases/2008/05/080522181503.htm

Lektion 1 From Brain Dynamics to Consciousness: A Prelude to the Future of Brain-Based Devices, Gerald Edelman.
[googlevideo=http://video.google.com/videoplay?docid=7437432153763631391&q=From+Brain+Dynamics+to+Consciousness&ei=PjA4SLHvNKjkiQKEtKnwAw]

Lektion 2 The Emergence of Intelligence in the Neocortical Microcircuit, Henry Markram.
[googlevideo=http://video.google.com/videoplay?docid=-2874207418572601262&q=The+Emergence+of+Intelligence+in+the+Neocortical+Microcircuit&ei=aTA4SMzCOYjgiQKHvKzrAw]

Lektion 3 The Mechanism of Thought, Robert Hecht-Nielsen.
[googlevideo=http://video.google.com/videoplay?docid=4572207081038401578&q=The+Mechanism+of+Thought&ei=lzA4SKPNKIv-iQLbzaHyAw]

Lektion 4 Hierarchical Temporal Memory: Theory and Implementation, Jeff Hawkins.
[googlevideo=http://video.google.com/videoplay?docid=-2500845581503718756&q=Hierarchical+Temporal+Memory&ei=uzA4SOPfLo2cjQL5yuTjAw]

Lektion 5 Panel: How the brain works, what it computes, and how/when we might build intelligent machines, James Albus, Theodore Berger, Kwabena Boahen, Ralph Linsker, Jerry Swartz.
[googlevideo=http://video.google.com/videoplay?docid=200924984898632631&q=How+the+brain+works&ei=4DA4SOShApaCigKTlaXUAw]

Lektion 6 The Uniqueness of the Human Brain, V.S. Ramachandran.
[googlevideo=http://video.google.com/videoplay?docid=-4684607596399338611&q=The+Uniqueness+of+the+Human+Brain&ei=CDE4SNCSE4ycigLI9J3hAw]

Lektion 7 Beyond Dualism, John Searle.
[googlevideo=http://video.google.com/videoplay?docid=-3295448672203577230&q=beyond+dualism&ei=OjE4SI7qMpXsigK53aD0Aw]

Lektion 8 Cortical Dynamics of Working Memory, Joaquin Furster.
[googlevideo=http://video.google.com/videoplay?docid=-3002336180397686566&q=cortical+dynamics&ei=dTE4SO-OJZXsigK53aD0Aw]

Lektion 9 A Quantitative Theory of Cortex, Leslie Valiant.
[googlevideo=http://video.google.com/videoplay?docid=-3948805418537584481&q=quantative+theory+of+cortex&ei=jzE4SJHBH42cjQL5yuTjAw]

Lektion 10 The Four C's of Neuroinformation Theory: Coding, Computing, Control and Cognition, Toby Berger.
[googlevideo=http://video.google.com/videoplay?docid=-5222739566501947160&q=The+Four+C%27s+of+Neuroinformation+&ei=rjE4SPOMG4-cigL4pODkAw]

Lektion 11 Consciousness, Christof Koch.
[googlevideo=http://video.google.com/videoplay?docid=1012772740345851560&q=consciousness+koch&ei=DzI4SKDwJI7giQK41IjWAw]

Lektion 12 Panel: The Future of Cognitive Computing.
[googlevideo=http://video.google.com/videoplay?docid=41347195024906280&q=future+of+cognitive+compution&ei=LTI4SLbxFpuKigKC4K3vAw]

I den video jeg har valgt at linke her taler han ved Ted Talks (kan også findes på youtube her. Et arrangement der hvert år bliver holdt på Long Beach i Californien. Mottoet for konferencen er "Ideas worth spreading", og der er da også mange interessante vinkler og perspektiver der bliver taget op af de meget forskellige debatoplæggere. Men her har jeg altså valgt at præsentere V.S Ramachandrans rejse ind i vores hjerne. God fornøjelse:

MIT neuroscientist Rebecca Saxe is tackling those tough questions and many others. Her goal is no less than understanding how the brain gives rise to the abilities that make us uniquely human--making moral judgments, developing belief systems and understanding language.

Hun forsker blandt andet i hvordan og hvor vi foretager bedømmelser af andres tanker. Altså hvordan vi hver især forholder os til andres meninger og tanker.

While it's impossible to observe thoughts directly, it is possible to measure which brain regions are active while people are thinking about certain things. Saxe probes the brain circuits underlying human thought with a technique called functional magnetic resonance imaging (fMRI), a type of brain scan that measures blood flow.

Using fMRI, she has identified an area of the brain (the temporoparietal junction) that lights up when people think about other people's thoughts, something we do often as we try to figure out why others behave as they do.

Som det fremgår af artiklen "Exploring The Mechanics Of Judgment, Beliefs: Technique Images Brain Activity When We Think Of Others" er moral og bedømmelse et af de områder hun gerne vil forstå bedre. Saxe kommer således blandt andet ind på det samme område som Marc Hauser er igang med at undersøge (se her). Og det er fx nogle af de samme problematikker Saxe tager op i sin undersøgelser:

Saxe's recent studies use fMRI to delve into moral judgment--specifically, what happens in the brain when people judge whether others are behaving morally. Subjects in her studies make decisions regarding classic morality scenarios such as whether it's OK to flip a switch that would divert a runaway train onto a track where it would kill one person instead of five people.
...
"Two events with the exact same outcome get extremely different reactions based on our inferences of someone's mental state and what they were thinking," she says.

For example, judgments often depend on whether the judging person is in conflict with the person performing the action. When a soldier sets off a bomb, an observer's perception of whether the soldier intended to kill civilians depends on whether the soldier and observer are on the same side of the conflict.

Og netop det sidste gør at Saxe udvider sin forskning på dette område ved sine fremtidige undersøgelser. Hun vil søge at forstå hvordan børn udvikler forståelse og perceptioner af andre grupperinger, og således hvordan vores forhold til en anden person influere vores bedømmelse af tanker og handling. Hendes case er hvordan børn udvikler forestillinger om rivaliserende grupperinger i forbindelse med konflikter.

In a future study, Saxe and one of her postdoctoral associates plan to study how children develop beliefs regarding groups in longstanding conflict with their own group (for example, Muslims and Serbs in the former Yugoslavia, or Sunnis and Shiites in parts of the Middle East).

They hope to first identify brain regions that are active while people think about members of a conflict group, then observe any changes in brain activity following mediation efforts such as "peace camps" that bring together children from two conflict groups.

Vil det således være muligt at se forskelle i kommunikation i hjernen, alt efter hvordan den enkelte forholder sig til en anden gruppe mennesker? Meningen med Saxe's undersøgelser er at ville kunne øge forståelsen af hvordan vi bedømmer og fortolker hinandens handlinger, udsagn, tanker mv.; hvilke kommunikationer der foregår i forskellige situationer.

Mere forskning på området om hvordan en kulturel opdragelse influere vores perceptioner og bedømmelser kan ses her

Kilde:
Massachusetts Institute Of Technology (2008, May 18). Exploring The Mechanics Of Judgment, Beliefs: Technique Images Brain Activity When We Think Of Others. ScienceDaily. Retrieved May 19, 2008, from http://www.sciencedaily.com/releases/2008/05/080515212112.htm

[googlevideo=http://video.google.com/videoplay?docid=-4317251159318118415]

researchers in The Netherlands were able to detect biochemical differences in the brains of individuals with generalized social anxiety disorder (also known as social phobia), providing evidence of a long-suspected biological cause for the dysfunction.
...
Serotonin and dopamine (neurotransmitters, or substances responsible for transferring signals from one neuron to another) act upon receptors in the brain. If the neurotransmitters are out of balance, messages cannot get through the brain properly. This can alter the way the brain reacts to normal social situations, leading to anxiety.

Artiklens navn Are Anxiety Disorders All In The Mind? antyder hvad forskere overvejer ved sådanne resultater. Kan forskellige forbier og angster anspores i hjernen som udelukkende en biologisk dysfunktion? Har hvert enkelt individ således ved en biologisk forudsætning større eller mindre chance for at få fx social fobi? Og hvor stor en rolle spiller miljøets omstændigheder ind? Meget tyder, i hvert fald ifølge dette studier, at forskellige psykologiske sygdomme kan forklares ved fysiologiske omstændigheder i hjernen. Spørgsmålet melder sig så om hvorvidt det vil være muligt at "helbrede" folk fx gennem stimulanser specielle neurotransmittere.

"Although there are no direct implications for treatment as a result of this study yet, it is another piece of evidence showing biological abnormalities, which may lead to new therapeutic approaches and insight into the origins of the disorder," said Dr. van der Wee.

Kilde:
Society of Nuclear Medicine (2008, May 12). Are Anxiety Disorders All In The Mind?. ScienceDaily. Retrieved May 13, 2008, from http://www.sciencedaily.com/releases/2008/05/080512105719.htm

Og i den lidt mere seriøse afdeling en lille introduktion til neurovidenskab fortalt af skuespilleren Alan Alda og produceret af "The Kavli Foundation"

Til folk der skulle være interesseret (det er jeg i hvert fald) udkommer Marco Iacoboni snarligt (13. maj) med en ny bog om spejlneuroner med den meget sigende titel "Mirroring People"

Discover Magazine har en lille intro til bogen her

Og et link til et lille uddrag af bogen, som jeg vil vende tilbage til, tror jeg, når jeg har erhvervet mig bogen og haft tiden til at læse den :)

What is the self? How does the activity of neurons give rise to the sense of being a conscious human being? Even this most ancient of philosophical problems, I believe, will yield to the methods of empirical science. It now seems increasingly likely that the self is not a holistic property of the entire brain; it arises from the activity of specific sets of interlinked brain circuits.

En af de interessante spørgsmål i forhold til den bevidstedhedsform vi har er hvordan den har udviklet sig. Nogen forskere har foreslået at den har udviklet sig på baggrund af gevinsten ved at kunne anticipere hvad en anden vil gøre i fremtiden. V.S. Ramachandran udtrykker sin tilgang:

Specifically, I suggest that "other awareness" may have evolved first and then counterintutively, as often happens in evolution, the same ability was exploited to model ones own mind — what one calls self awareness. I will also suggest that a specific system of neurons called mirror neurons are involved in this ability.

Spejlneuronerne, (som egentlig kræver en særegen introduktion i sig selv, kommer senere) spiller ifølge Ramachandran en væsentlig rolle i forhold til den evolutionære udviklingen af bevidstheden.

Primates (including humans) are highly social creatures and knowing what someone is "up to" — creating an internal simulation of his/her mind — is crucial for survival, earning us the title "the Machiavellian primate". In an essay for Edge (2001) entitled "Mirror Neurons and the Great Leap Forward" I suggested that in addition to providing a neural substrate for figuring out another persons intentions (as noted by Rizzolati's group) the emergence and subsequent sophistication of mirror neurons in hominids may have played a crucial role in many quintessentially human abilities such as empathy, learning through imitation (rather than trial and error), and the rapid transmission of what we call "culture". (And the "great leap forward" — the rapid Lamarckian transmission of "accidental") one-of-a kind inventions.

 
Naturen af selvet

Ramachandran mener således at spejlneuronerne også spiller en væsentlig rolle i forståelsen af selvets natur. Kort sagt mener han at den evne der var en evolutionær fortrin, at kunne bedømme andres fremtidige handlinger, blev vendt indad og således skabte forudsætningen for det vi kalder bevidsthed, hvor vi føler at vi kan anskue og bedømme os selv:

How does all this lead to self awareness? I suggest that self awareness is simply using mirror neurons for "looking at myself as if someone else is look at me" (the word "me" encompassing some of my brain processes, as well). The mirror neuron mechanism — the same algorithm — that originally evolved to help you adopt another's point of view was turned inward to look at your own self. This, in essence, is the basis of things like "introspection". It may not be coincidental that we use phrases like "self conscious" when you really mean that you are conscious of others being conscious of you.

...

the ability to turn inward to introspect or reflect may be a sort of metaphorical extension of the mirror neurons ability to read others minds. It is often tacitly assumed that the uniquely human ability to construct a "theory of other minds" or "TOM" (seeing the world from the others point of view; "mind reading", figuring out what someone is up to, etc.) must come after an already pre- existing sense of self. I am arguing that the exact opposite is true; the TOM evolved first in response to social needs and then later, as an unexpected bonus, came the ability to introspect on your own thoughts and intentions.

Dette, spejlneuronernes rolle, er som Ramachandran skriver i sin artikel, ikke fyldestgørende for at forklare selvet, men det giver nogen stærke indikationer om hvordan vi fremover kan søge bedre forståelse af selvet. Andre primater har også spejlneuroner i funktion, men har samtidig ikke en selvbevidsthed. Hvorledes adskiller denne primat fra andre på dette område? Hvilke fysiologiske omstændigheder har gjort det muligt for selvbevidsteheden at udvikle sig?

They may have to reach a certain critical level of sophistication that allowed them to build on earlier functions (TOM) and become linked to certain other brain circuits, especially the Wernickes ("language comprehension") area and parts of the frontal lobes.

Undersøgelser af forskellige patienter med forskellige neurologiske skader eller deformiteter giver også et væsentligt fingerpeg om at det er i forbindelse med spejlneuronerne at vi skal hente væsentlige aspekter af vores forståelse af selvet. Og Ramachandran er også optimistisk i forhold til neurovidenskabens rolle i forhold til at forstå og kortlægge, det som han kalder "Science's greatest riddle".

Some years ago we examined a patient with a syndrome called anosognosia who had a lesion in his right parietal lobe and vehemently denied the paralysis. Remarkably the patient also denied the paralysis of another patient sitting in an adjacent wheelchair! (who failed to move the arm on command from the physician.) Here again was, evidence that two seemingly contradictory aspects of self — its the individuation and intense privacy vs. its social reciprocity — may complement each other and arise from the same neural mechanism, mirror neurons.

...

Have we solved the problem of self? Obviously not — we have barely scratched the surface. But hopefully we have paved the way for future models and empirical studies on the nature of self, a problem that philosophers have made essentially no headway in solving. (And not for want of effort — they have been at it for three thousand years). Hence our grounds for optimism about the future of brain research — especially for solving what is arguably Science's greatest riddle.

Hvis man vil hører eller læse, hvilket jeg vil anbefale at man gør, mere af V.S. Ramachandran er der fx denne video, hvor han diskutere hans seneste bog "A Brief Tour of Human Consciousness", fra 2004, eller man kan kigge på nogle af de forskellige artikler han har skrevet for Edge her, hvor man også kan finde et link til hans egen hjemmeside, hvor der er flere henvisninger til forskellige publikationer, interviews mv.

Den skal nemlig ikke bare kunne lære sprog. Den skal lære at bevæge sig, lære at gribe om ting. Og ligefrem lærer at interagere. Og et af de store mål ved at skabe denne lille robot er, at forstå den funktion i vores egen hjerner som kaldes 'spejlneuroner', hvilket vil sige hvordan vi gennem observationer og erfaring lærer at forstå ting og udvikle vores egne evner. Seks forskellige forskningscentre har fået ansvaret for at 'opdrage' og udvikle denne lille robot's kognition og derved tænkning:

The team behind the iCub robot believes it, like children, will learn best from its own experiences.

The technologies developed on the iCub platform – such as grasping, locomotion, interaction, and even language-action association – are of great relevance to further advances in the field of industrial service robotics.

The EU-funded RobotCub project, which designed the iCub, will send one each to six European research labs. Each of the labs proposed winning projects to help train the robots to learn about their surroundings – just as a child would.

The six projects include one from Imperial College London that will explore how ‘mirror neurons’ found in the human brain can be translated into a digital application. ‘Mirror neurons’, discovered in the early 1990s, trigger memories of previous experiences when humans are trying to understand the physical actions of others. A separate team at UPF Barcelona will also work on iCub’s ‘cognitive architecture’.

At the same time, a team headquartered at UPMC in Paris will explore the dynamics needed to achieve full body control for iCub. Meanwhile, researchers at TUM Munich will work on the development of iCub’s manipulation skills. A project team from the University of Lyons will explore internal simulation techniques – something our brains do when planning actions or trying to understand the actions of others.

Over in Turkey, a team based at METU in Ankara will focus almost exclusively on language acquisition and the iCub’s ability to link objects with verbal utterances.

 Processen skal foregå på en tilsvarende måde som vi mennesker gennemgår igennem vores udvikling og opdragelse og således skal foregå ved at robotten observere eller 'sanser' andre gribe noget, snakke, gå eller interagere og derved lærer hvordan den selv skal gøre disse forskellige ting.

The iCub robots are about the size of three-year-old children, with highly dexterous hands and fully articulated heads and eyes. They have hearing and touch capabilities and are designed to be able to crawl on all fours and to sit up.

Humans develop their abilities to understand and interact with the world around them through their experiences. As small children, we learn by doing and we understand the actions of others by comparing their actions to our previous experience.

The developers of iCub want to develop their robots’ cognitive capabilities by mimicking that process. Researchers from the EU-funded Robotcub project designed the iCub’s hardware and software using a modular system. The design increases the efficiency of the robot, and also allows researcher to more easily update individual components. The modular design also allows large numbers of researchers to work independently on separate aspects of the robot.

Og ligesom det er små skridt mennesker tager i udviklingen gennem opvæksten er det ligeledes små skridt forskerne anticipere for iCub

But the first and key skill iCub needs for learning by doing is an ability to reach towards a fixed point. By October this year, the iCub developers plan to develop the robot so it is able to analyse the information it receives via its vision and feel ‘senses’. The robot will then be able to use this information to perform at least some crude grasping behaviour – reaching outwards and closing its fingers around an object.

“Grasping is the first step in developing cognition as it is required to learn how to use tools and to understand that if you interact with an object it has consequences,” says Giorgio Metta. “From there the robot can develop more complex behaviours as it learns that particular objects are best manipulated in certain ways.”

Ved at udvikle disse systemer gør det det ikke bare muligt at skabe robotter der ville kunne være til stor nytte i samfundet. I Korea og Japan er de første robotter allerede i brug i sundheds- og ældreplejen, og for den sags skyld i mange forskellige industrier. Men det vil også være til stor nytte for at forstå vores egen bevidsthed, vores tænkning, og hvad det er der foregår i de forskellige processer i hjernen. Skræmmescenarierne for udviklingen af kunstig intelligens ville måske være Hal 9000 fra "Rumrejsen år 2001" eller måske Marvin, the Paranoid Android fra "The Hitchhiker's Guide to the Galaxy".

Kilde:
ICT Results (2008, April 26). Next Step In Robot Development Is Child's Play. ScienceDaily. Retrieved April 27, 2008, from: http://www.sciencedaily.com/releases/2008/04/080421162240.htm

 Robotter i brug i Japan, Korea og Norge:
http://news.bbc.co.uk/1/hi/sci/tech/1829021.stm
http://www.msnbc.msn.com/id/23438322/

http://www.msnbc.msn.com/id/21773646/

http://www.reuters.com/article/scienceNews/idUSL0719538520080207

I artiklen, Major Step Forward In Understanding How Memory Work, fra Science Daily, der trækker på resultater fremlagt i en artikel i det anerkendte videnskabsmagasin Neuron, bliver det gjort klart at forskerne ved at blokere en specifik kommunikation i hjernen på en rotte, er kommet nærmere på at kunne redegøre for hvordan vores visuelle og genkendelseshukommelse fungere.

By blocking certain mechanisms that control the way that nerve cells in the brain communicate, scientists from the University of Bristol have been able to prevent visual recognition memory in rats.

This demonstrates they have identified cellular and molecular mechanisms in the brain that may provide a key to understanding processes of recognition memory.

Sådan en viden kan have stor indflydelse på forskellige ting i vores liv der, hvor hukommelse er et vigtigt element, hvilket mildt sagt vil sige stort set alt. Og mere konkret kan øget viden om hvordan hukommelsen helt præcist skabes og lagres øge muligheden for at hjælpe mennesker med sygdomme som alzheimer, der netop angriber evnen til at huske.

Dr Sarah Griffiths, lead author on the paper, explained: "Nerve cells in the perirhinal cortex of the brain are known to be vital for visual recognition memory. Using a combination of biological techniques and behavioural testing, we examined whether the mechanisms involved in synaptic plasticity are also vital for visual recognition memory."

In their experiments, they were able to identify a key molecular mechanism that controls synaptic plasticity in the perirhinal cortex. They then demonstrated that blocking the same molecular mechanism that controls synaptic plasticity also prevented visual recognition memory in rats. This shows that such memory relies on specific molecular processes in the brain.

Professor Bashir added: "The next step is to try to understand the processes that enable visual memories to be held in our brains for such long periods of time, and why these mechanisms begin to break down in old age."

 
En række forskellige forsøg søger netop, ved at lave "blokeringer" i kommunikation i hjernen, svar på hvad de forskellige molekylære og cellemekanismer, der er i hjernen, betyder for fx hukommelse, lyst, planlægning osv.. I teorien kunne man måske forestille sig at man i fremtiden aktivt ville kunne afhjælpe patienter med hukommelsessvigt når man netop forstår bedre hvilke mekanismer der gør sig gældende for hukommelsen. Omvendt ville det måske også være muligt at foretage negative indgreb og således ville et menneske kunne bestemme hvilke ting et andet menneske vil kunne huske. Et skræmmende scenarie i forhold til neurovidensmæssig undersøgelser er hvorvidt det med bedre forståelse vil være reelt muligt for et menneske at styre et andet menneske, hvilket dog afvises som muligt af nogen forskere. Men på de mere positive sider ville bedre forståelse af hukommelsen også være afhælpende på børns almindelige opvækst, hvor børn, der har svære problemer med hukommelsen, ville kunne afhjælpes. Generelt er der forskellige forskning der muligvis ville kunne bruges til at give forskellige mennesker bedre muligheder i samfundet og det er formentligt et emne der vil blive diskuteret meget i fremtiden, når viden, teknik mv. bliver billigere og bedre.

Kilde:

University of Bristol (2008, April 25). Major Step Forward In Understanding How Memory Works. ScienceDaily. Retrieved April 26, 2008, from http://www.sciencedaily.com/releases/2008/04/080423121427.htm

Det omhandler, som nogen måske vil genkende, om hvorfor vi har 'moral'. Marc Hauser mener at vi hver især har en universel moralsk grammatik iboende på tilsvarende vis som vi har en universel sproglig grammatik. Sidstnævnte bygger Noam Chomsky's teori om at vi også har nogle grundelement eller en universel grammatik for sprog. Disse universelle grammatikker er dog i sin natur meget simple og danner kun udgangspunkt for den videre udvikling. Men de bunder samtidig også i at man både i den sproglige og i det morale kan finde nogen grundlæggende lighedspunkter på tværs af kulturer over verden. At vi således som mennesker deler nogle grundforudsætninger for at skabe sprog og moral. I begge tilfælde er disse elementer af den evolutionære process og er de byggeklodser, for henholdsvis sprog og moral, vi mennesker fik med. I tilfældet af skader på bestemte områder i hjernen viser studier at mennesker eventuelt kan få problemer med at skabe sætninger eller fx divergere grundlæggende fra nogle moralske overvejelser. I det sidstnævnte tilfælde var der i Hausers forsøg tale om at forsøgspersoner, der havde en specifik skade på frontallappen, der er involveret i følsesmæssige beslutninger, medførte en ændring i den moralske grammatik. Som nævnt er forestillingen, at den moralske grammatik kun er grundforudsætningen for vores moralske kompas. Moralen bliver således også påvirket af kulturen, der i høj grad også former vores persceptioner af forkert og rigtigt i forskellige situationer. Som Lene Frank udtrykte er det således et samarbejde mellem Humes ide om at vores hjerne udelukkende er et lærende organ og Kants ide om at der er nogle universelle spilleregler.

Det er stadig et omdiskuteret emne og Marc Hauser har som sådan ikke fået bred accept, i hvert fald ikke endnu. Umiddelbart har jeg det også sådan at fx sådan noget som kanabalisme stikker lidt ud. Her har vi en kulturel divergent der i den grad stikker udenfor. Men alligevel kan disse mennesker måske stadig dele nogle grundlæggende elementer med resten af menneskeheden og ville hellere ikke skubbe den tykke mand ud fra broen for at redde den lille gruppe mennesker.

Hvad synes I?

 Til interesserede der vil læse mere om Naom Chomsky's teori om sprogets grammatik: http://www.chomsky.info/articles/195609--.pdf

Og mere om Marc Hauser's teori:
http://www.centerforinquiry.net/uploads/attachments/HauserSinger.pdf

Undersøgelsen

I artiklen "Decision-making May Be Surprisingly Unconscious Activity" får vi således fortalt historien om en gruppe forskere der har forsøgt at kigge nærmere på hvad der foregår i hjernen i forhold til det at tage beslutning. Det tegner til at vi foretager vores beslutninger ubevidst og at det kan foregår op til 7 sekunder før vi registrere det. Professor John-Dylan Haynes udtaler sig om forsøget, hvor testpersonerne skulle foretage et valg uden press om de ville trykke på enten den højre eller venstre knap:

"Many processes in the brain occur automatically and without involvement of our consciousness. This prevents our mind from being overloaded by simple routine tasks. But when it comes to decisions we tend to assume they are made by our conscious mind. This is questioned by our current findings"

Sådan nogle resultater får nogen forskere til at argumentere for at vi reelt set ikke har noget der hedder 'fri vilje', men at vores beslutninger foregår gennem vores hjernes, i dette tilfælde, ja beslutningssystem, som vi ikke er bevidste om.

"This unprecedented prediction of a free decision was made possible by sophisticated computer programs that were trained to recognize typical brain activity patterns preceding each of the two choices. Micropatterns of activity in the frontopolar cortex were predictive of the choices even before participants knew which option they were going to choose. The decision could not be predicted perfectly, but prediction was clearly above chance. This suggests that the decision is unconsciously prepared ahead of time but the final decision might still be reversible."

Det er ikke første gang der bliver undersøgt i forholdene omkring beslutningstagen. En tidligere undersøgelse har også indikeret, at beslutningerne bliver taget før vi "egentlig" tager dem. Denne undersøgelse havde dog ikke valgt at undersøge en tilsvarende tidshorisont, men kunne stadig også måle en aktivitet der gik forud den bevidste beslutningstagen.

Men der mangler stadig nogle svar

Undersøgelsen er dog ikke endeligt konkluderende hvad angår den frie vilje. Og udelukker således ikke direkte en bevidst fri vilje. Fortsatte undersøgelser skal foretages og der skal blandt andet ses nærmere på, hvorledes beslutningen kan blive ændret som undersøgelsen også indikerede skete.

"Our study shows that decisions are unconsciously prepared much longer ahead than previously thought. But we do not know yet where the final decision is made. We need to investigate whether a decision prepared by these brain areas can still be reversed"

Men undersøgelsens resultater giver også et billede af hvordan hjernen fungere, hvor der foregår en tydelig egentlig kommunikation neurologisk før vi som enkeltindivid føler vi tager en beslutning.

Kilde:
Max-Planck-Gesellschaft (2008, April 15). Decision-making May Be Surprisingly Unconscious Activity. ScienceDaily. Retrieved April 15, 2008, from http://www.sciencedaily.com/releases/2008/04/080414145705.htm

Artikel om hvordan vores hjerne fungere i forhold til planlægning og hukommelse:
http://www.sciencedaily.com/releases/2007/01/070102092224.htm

Artikel og video om udviklingen indenfor hjernescanninger:
http://www.sciencedaily.com/videos/2007/0710-brain_scans_of_the_future.htm