[googlevideo=http://video.google.com/videoplay?docid=-602962800234523793&q=horizon&ei=qxpWSPi0C4WkjAKG0eXuDg]

Gay men and straight women share some characteristics in the area of the brain responsible for emotion, mood and anxiety, researchers said on Monday in a study highlighting the potential biological underpinning of sexuality

Der var således ligheder mellem scanningerne af heterosexuelle kvinder og homoseksuelle mænd i fx forholdet mellem venstre og højre hjernehalvdel, der hos begge grupper var lige store. Omvendt have homoseksuelle kvinder og heteroseksuelle mænd den samme asymmetri i forholdet mellem de to hjernehalvdele.

Brain scans of 90 volunteers showed that the brains of heterosexual men and homosexual women were slightly asymmetric with the right hemisphere slightly larger than the left, Ivanka Savic and Pers Lindstrom wrote. The brains of gay men and heterosexual women were not.

Then they measured blood flow to the amygdala -- the area key for the "fight-or-flight" response -- and found it was wired in a similar fashion in gay men and heterosexual women as well as lesbians and heterosexual men.

Spørgsmålet er hvorfor der opstår disse forskelle. Forskerne mener ikke at det skyldes 'kultur'; altså at det skyldes forhold i opdragelsen og impulserne, men mener derimod at der er nogle mekanismer bagved, under graviditeten eller efterfølgende.

Læs mere her, her, her og her.

Nogen mener således at seksualiteten kan være "hardwired"

Dr Qazi Rahman, a lecturer in cognitive biology at Queen Mary, University of London, said that he believed that these brain differences were laid down early in foetal development.

"As far as I'm concerned there is no argument any more - if you are gay, you are born gay," he said.

The amygdala, he said, was important because of its role in "orientating", or directing, the rest of the brain in response to an emotional stimulus - be it during the "fight or flight" response, or the presence of a potential mate.

"In other words, the brain network which determines what sexual orientation actually 'orients' towards is similar between gay men and straight women, and between lesbian women and straight men.

"This makes sense given that gay men have a sexual preference which is like that of women in general, that is, preferring men, and vice versa for lesbian women."

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.
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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"

Session 1 med introduktion af Michael Shermer. Herefter følger oplæg af Roger Bingham (0:19 Aun Aprendo: Still Learning about Minds) Christof Koch (0:51 The Quest for Consciousness: A Neurobiological Approach), Alison Gopnik (1:29 Children as Scientists: How the Brain Learns to Think) og paneldiskussion ( 2:01 )med Michael Shermer, Christof Koch og Alison Gopnik. Vi bliver introduceret til den videnskabelige indgangsvinkel til forskningen i hjernen og dens udvikling og hvilke problematikker og områder der kræver opmærksomhed.
[googlevideo=http://video.google.com/videoplay?docid=4831204601412295941&q=&hl=en]

Session 2 Oplæg af Richard J. McNally (0:03 In Search of Memory - True, False, Remembered, Repressed, Recovered), Terrence Sejnowski (0:43 Sleep, Dreams and Subconscious), Susan Blackmore (1:29 The Grand Illusion of Consciousness)
[googlevideo=http://video.google.com/videoplay?docid=6417527326328810589&hl=en]

Session 3 Oplæg af John Allman (0:01The Search for the Neurological Basis of the Social Emotions), Paul Zak (0:31 From Whence Trust Comes: Oxytocin and Behavioral Economics), Hank Schlinger (1:00 Consciousness is Nothing but a Word: Debunking the Last Great Myth of Psychology), Ursula Goodenough (1:33 From Biology to Consciousness to Morality) og paneldiskussion ( 2:08 ) med John Allman, Paul Zak, Hank Schlinger, Ursula Goodenough, Terry Sejnowski og Susan Blackmore.
[googlevideo=http://video.google.com/videoplay?docid=-4692065277230230087&q=&hl=en]

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.
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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.´
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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.
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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.