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POPSWhy working out may help memory Glucose metabolism naturally slows with age, and memory begins to decline in our 30s, says co-author Scott Small, an associate professor of neurology at Columbia University Medical Center in New York. The new study suggests a possible association between the two, because elevated blood sugar appears to damage the dentate gyrus, Small says. The dentate gyrus's exact function is unknown. But it's one of several circuits in the hippocampus that, if disrupted, impairs memory, such as a person's ability to learn the names of new people or to remember where they parked their car. The possible connection between its dysfunction and poor glucose regulation may explain earlier observations that exercise benefits the dentate gyrus, Small says. Until now, scientists believed that physical activity reduced the risk of age-related memory loss by allowing glucose to be absorbed more quickly into muscle cells, but were not sure why.
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POPSYawning Is Caused by the Brain Overheating One of the main reasons why the team selected the parakeets for the study was the fact that these birds almost never engaged in group yawning, so they were deemed reliable test subjects. During the tests, they were subjected to three temperatures – one that increased constantly, one that was high, to begin with, and one for control. Examinations proved that the brain sought to cool itself by triggering the yawning reflex when the outside temperature was lower than that inside the body. “For instance, yawning should not occur when ambient temperatures exceed body temperature, as taking a deep inhalation of warm air would be counterproductive,” Gallup adds. “In addition, yawning when it is extremely cold may be maladaptive, as this may send unusually cold air to the brain, which may produce a thermal shock.”
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POPSBuilding a machine that can learn from experience There's another requirement: The finished cognitive computer should be as small as a the brain of a small mammal and use as little power as a 100-watt light bulb. It's a major challenge. But it's what our brains do every day. "Value systems or reward systems are important aspects," he said. "Learning is crucial because it needs to learn from experience just like we do." It won't be an easy task, says Tononi, a veteran of earlier efforts to create cognitive computers. Even the brains of the smallest mammals are quite impressive when you consider what tasks they perform with a relatively small volume and energy input. "I would be happy to create a mouse brain," Tononi says. "A mouse brain is quite remarkable. And from there, it shouldn't be too hard to scale up to a rat brain, and then a cat or monkey brain."
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POPSBrain Cells That Are A Key To Learning Discovered n experiments the researchers directly observed the convergent neurons where learning is suspected of taking place. These neurons responded to both a conditioned stimulus, in this case a novel saccharine solution, and an unconditioned stimulus, in the form of lithium chloride that made rats sick. Convergent activation is considered a key event for subsequent plasticity, according to Bernstein. Until now, however, there has been scant direct evidence of this activation during learning in the mammalian brain.
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POPSParalyzed Man Speaks Again Using Brain Implant So they knew his brain's speech centers were still functioning. They just needed a way to connect those speech centers to a speech synthesizer - an artificial mouth if you will. Researchers implanted a special kind of electrode in his brain, one that's "impregnated with neurotrophic factors" that encourage brain neurons to grow into and around the electrode. Essentially this electrode forms a very strong connection with brain neurons, which results in a strong signal that reliably comes from the same part of the patient's brain over time. Over a period of weeks, Guenther and his team worked to decode the signals coming from the man's brain. Eventually, he was able "to produce three vowel sounds with good accuracy," said Guenther. The man produces these sounds as quickly as he would normal speech, and Guenther added, "The long-term goal within five years is to have him use the speech brain–computer interface to produce words directly."
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POPSCooling the Brain Michale Fee and his colleagues created the cooling device using technology similar to that used in portable electronic beverage coolers. They say that it could be used to study other complex behaviors, such as walking or swimming. "We can also use this cooling technology to discover which brain regions control the timing of different complex behaviors in different animals, something that has been very difficult to assess until now," Fee said in the release. "We know that HVC is related in some ways to human cortex, so it could be showing us a very general mechanism for representing the passage of time within the brain." The research was published today in the journal Nature.
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POPSThe Power of the Memory Molecule Nevertheless, this paper marks an important advancement in understanding how chemical pathways in the brain are able to encode and recall events and experiences.
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POPSDoes the Human Mind Have Potential “Super Powers”? So, if all of us have latent super-abilities, is it possible to activate them permanently, or at least periodically, without compromising normal brain functioning? Probably, say the Australian scientists who used transcranial magnetic stimulation to temporarily switch off the frontal temporal lobe of volunteers. Afterwards the subjects showed an immediate improvement in calendar calculating, naming the day of the week of any recent history event, and in their artistic abilities. Of course these were just the abilities tested. Scientists do not know all of the latent abilities that humans may possess. It has been predicted that more advanced neurological studies may someday discover how to allow “Regular” people to tap into the incredible latent powers of their own mind, and thereby unleashing some of the “superhuman” potential in all of us.
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POPSArtificial eye implant sits mostly outside the eye. The coil around the iris receives wireless power and image data from a microcontroller that can be carried on a belt. The coil transmits data to electronics inside a waterproof titanium case. The electronics controls an electrode array (not visible) connected to nerves in the back of the retina. This device would be more bio-compatible than others, because it sits mostly outside the eye and therefore carries a reduced risk of inflammation and of a decline in performance with time. So far it has only been tested in pigs but human trials are planned for 2010.
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POPSBeauty and the Brain Future work may elucidate the long-term effects of one's surroundings on brain function and the relationship between aesthetically pleasing spaces and their functionality. What one considers beautiful is, of course, influenced by culture, learning, and experience, and not everything we find beautiful will ultimately be traceable to the structure and function of our brain. The larger question "What is beauty?" still poses a major challenge, but answering it no longer seems so impossible.
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POPSThe 'satellite navigation' in our brains
n a follow-up study, Dr Spiers and Professor Maguire used the Playstation2 video game "The Getaway" to examine how taxi drivers use their hippocampus and other brain areas when they navigate. Taxi drivers used the virtual reality simulation to navigate the streets of London whilst lying in an fMRI brain scanner. The researchers found that the hippocampus is most active when the drivers first think about their route and plan ahead. By contrast, activity in a diverse network of other brain areas increases as they encounter road blocks, spot expected landmarks, look at the view and worry about the thoughts of their customers and other drivers. "The hippocampus is crucial for navigation and we use it like a 'sat nav'," says Dr Spiers from the Institute of Behavioural Neuroscience at UCL. "London taxi drivers, who have to know their way around hundreds of thousands of winding streets, have the most refined and powerful innate sat navs, strengthened over years of experience."
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POPSGender differences seen in brain connections While the effect of high synaptic density in this region is unknown, the team suspects that there may be other regions where women out-synapse men. In any case, says DeFelipe, although different synaptic densities indicates different circuitry between men and women, men shouldn't get too cocky: the density of synapses in mice is greater than in humans.
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POPSScientists to study synthetic telepathy The brain-computer interface would use a noninvasive brain imaging technology like electroencephalography to let people communicate thoughts to each other. For example, a soldier would “think” a message to be transmitted and a computer-based speech recognition system would decode the EEG signals. The decoded thoughts, in essence translated brain waves, are transmitted using a system that points in the direction of the intended target. “Such a system would require extensive training for anyone using it to send and receive messages,” D’Zmura says. “Initially, communication would be based on a limited set of words or phrases that are recognized by the system; it would involve more complex language and speech as the technology is developed further.”
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POPSIntelligence and Empathy He stresses that the human mind does not qualify as a completely ‘General Intelligence’ but lies somewhere on the spectrum between AGI on one end and ‘Narrow AI’ on the other. This is one of several reasons why he does not expect AGI to be achieved by mimicking the workings of the human brain. He describes how our brains fool us into believing that we understand our actions and decisions when we don’t. And why modeling an AI too closely on the human brain might make it too, vulnerable to false notions. He also says, ‘I think virtual worlds are going to be absolutely critical to the development of Artificial General Intelligence.’ As well as ‘Right now connecting AI’s to virtual worlds is probably the best way to get an AI to have a general human-like embodied experience.’
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POPSSleep on It: How Snoozing Makes You Smarter This insight paved the way for a new understanding of organic chemistry and earned Kekulé a title of nobility in Germany. Although most of us have not been ennobled, there is something undeniably familiar about Kekulé’s problem-solving method. Whether deciding to go to a particular college, accept a challenging job offer or propose to a future spouse, “sleeping on it” seems to provide the clarity we need to piece together life’s puzzles. But how does slumber present us with answers?
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POPSThe cognitive neuroscience of magic Magic combines multiple principles of attention, awareness, trust and perception to both overtly and covertly misdirect the audience. Whether they are used for performance art or as a means to illicitly separate victims from their money and valuables, the accomplished performer uses robust and intuitive manipulative devices that are of great interest to neuroscientists pursuing the neural underpinnings of cognition, memory, sensation, social attachment, causal inference and awareness.
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POPSThe Brain Unmasked Diffusion spectrum imaging (DSI) is one of these twists. It uses magnetic resonance signals to track the movement of water molecules in the brain: water diffuses along the length of neural wires, called axons. Scientists can use these diffusion measurements to map the wires, creating a detailed blueprint of the brain's connectivity.
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POPSSkin cells from an 82-yr.-old ALS patient reprogrammed to form neurons Amyotrophic lateral sclerosis (ALS) is a form of motor neuron disease characterized by loss of motor neurons in the brain and spinal cord. These cells are involved in movements, which are generated by the sequential activity of cells in three regions of the central nervous system: they are planned by the activity of neurons in the premotor cortex (whose activity is monitored by brain-computer interfaces), and executed when this activity is relayed to motor neurons in the ventral horn of the spinal cord, via the cells in the primary motor cortex.
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POPSHuman-frog hybrids reveal autism's secrets To see if abnormalities in neurotransmitter signalling also underlie autism, Miledi's team collected brain samples from six deceased autistic patients, aged eight to 39. They fused brain-cell membranes, which house neurotransmitter receptors, together with Xenopus egg membranes. As a control, they did the same thing with brain cells from patients with no history of mental disorder. Miledi's team then doused the frog eggs in neurotransmitter chemicals, and measured the voltage generated within each egg. The neurotransmitter chemicals tell brain cells to pump charged molecules in and out the membrane, creating a voltage across the membrane. Since Xenopus eggs do not respond to the neurotransmitters, the human proteins are completely responsible for any electric current generated. Four of six autistic brains responded to neurotransmitters chemicals less vigorously than the controls.
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POPSTo Trust or Not to Trust? It has been hypothesized that oxytocin, a hormone recognized for its role in social attachment and facilitation of social interactions, is also important in the formation of trust. For instance, application of oxytocin to “investors” in experimental games increases their tendency to engage in social risks and trust someone else with their money (see this and this). The study by Baumgartner and his colleagues highlights the neural mechanisms through which oxytocin acts to facilitate trust behavior by investigating what happens in the brain when trust breaks down.
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POPSWill Our Future Brains Be Smaller? Why does the brain need these two decision-making areas? What benefit does the new cortex bring? After all, extra brain means extra weight and energy required to carry it around. Furthermore, is the older sub-cortical system now largely redundant? If so, could we expect it to atrophy in future humans so our brains become smaller? The results of their modelling showed that when the threat level is high, such as the risk of being attacked by a dangerous animal, it is very useful to have the fast-acting, if inaccurate, system. But when dealing with situations which don't occur very often, or complex scenarios with many conflicting cues such as social situations, the cortical system is of more use than the sub-cortical system.
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POPSGet Out of Your Own Way In ways we are only beginning to understand, the synapses and neurons in the human nervous system work in concert to perceive the world around them, to learn from their perceptions, to remember important experiences, to plan ahead, and to decide and act on incomplete information. In a rudimentary way, they predetermine our choices.
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POPSArtificial brain predicts death-row executions Since the direct approach had failed, the researchers turned to an artificial neural network (ANN) - an intelligent computer system, modelled after the human brain - that is able to deduce how various factors within a jumble of data relate to each other. The system can then take what it has learned and make predictions about a new set of data.To find out which factors might be linked to executions, the researchers first "trained" their ANN by entering the profiles of 1000 death row inmates between 1973 and 2000. Half of this sample of prisoners had been executed and the other half had survived. Each profile contained 18 factors, including the inmate's sex, age, race, marital status, educational level and information on their capital offences.
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POPSOf Two Minds, One Consciousness But perhaps even more profound, he explains how, even though split-brain patients have isolated hemispheres, they experience a unified consciousness—that is, feel as though they are of one mind.
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POPSObituary: Lorenzo Odone Reasoning that they could combat the disease by reducing the levels of very-long-chain fatty acids, they developed an oil derived from rapeseed and olive oil. When they gave the oil to Lorenzo, it reduced the levels of very-long-chain fatty acids in his blood, by blocking the enzymes that make them. The devotion and determination of Lorenzo's parents helped prolong his life and inspired the film, which came out in 1992. After its release, scientists were angered by suggestions that the oil was a cure for the disease.
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POPSParalysed man takes a walk in virtual world It is the first time a paralysis patient has succeeded in meeting a person and having a conversation in an Internet virtual world, they added. Researchers are now studying a system that would let patients create text messages by mentally selecting certain letters, said Junichi Ushiba, associate professor at the biosciences and informatics department of Keio Universty's Faculty of Science and Technology. "In the near future, they would be able to stroll through Second Life shopping malls with their brain waves... and click to make a purchase," Ushiba said.
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POPSIn the Works: MEMS Brain-Computer Interface As the electrodes are driven into the tissue, the software starts taking sample recordings to detect spikes of electrical activity at the electrode tip. When the software detects spikes, it moves forward in small increments and tracks how the signals change. After determining whether the signal has improved or gotten worse, it the algorithm moves the electrode to a new position and does more recording and comparing, driving the electrode in further if necessary until it finds the best signal. If the signal wanes, the algorithm will automatically adjust the electrode position to improve the signal.
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