The Cambridge Declaration on Consciousness
We declare the following: “The absence of a neocortex does not appear to preclude an organism from experiencing affective states. Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Nonhuman animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.”
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Sheep Brain Dissection: The Anatomy of Memory
By dissecting the brain of a sheep -an animal in which brain structure and function are similar to our own- we can see where memory processes take place. Throughout our lives, our memories are constantly being formulated, accessed, and filtered by the brain. Fleeting electrochemical connections made between brain cells help us remember the thoughts, skills, experiences and knowledge that make each of us unique.
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Try this exercise: Put this book down and go look in a mirror. Now move your eyes back and forth, so that you’re looking at your left eye, then at your right eye, then at your left eye again. When your eyes shift from one position to the other, they take time to move and land on the other location. But here’s the kicker: you never see your eyes move. What is happening to the time gaps during which your eyes are moving? Why do you feel as though there is no break in time while you’re changing your eye position? (Remember that it’s easy to detect someone else’s eyes moving, so the answer cannot be that eye movements are too fast to see.)
All these illusions and distortions are consequences of the way your brain builds a representation of time. When we examine the problem closely, we find that “time” is not the unitary phenomenon we may have supposed it to be. This can be illustrated with some simple experiments: for example, when a stream of images is shown over and over in succession, an oddball image thrown into the series appears to last for a longer period, although presented for the same physical duration. In the neuroscientific literature, this effect was originally termed a subjective “expansion of time,” but that description begs an important question of time representation: when durations dilate or contract, does time in general slow down or speed up during that moment? If a friend, say, spoke to you during the oddball presentation, would her voice seem lower in pitch, like a slowed- down record?
If our perception works like a movie camera, then when one aspect of a scene slows down, everything should slow down. In the movies, if a police car launching off a ramp is filmed in slow motion, not only will it stay in the air longer but its siren will blare at a lower pitch and its lights will flash at a lower frequency. An alternative hypothesis suggests that different temporal judgments are generated by different neural mechanisms—and while they often agree, they are not required to. The police car may seem suspended longer, while the frequencies of its siren and its flashing lights remain unchanged.
Read more: Brain Time
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Free Science Video Lectures, Classes and Tutorials
Over 20,000 free science video lectures from first class universities around the globe (English only).
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DARPA and NIH to fund ‘human body on a chip’ research
Researchers in the Department of Biological Engineering at MIT plan to develop a technology platform that will mimic human physiological systems in the laboratory, using an array of integrated, interchangeable engineered human tissue constructs, with $32 million funding over the next five years from the Defense Advanced Research Projects Agency (DARPA) and the National Institutes of Health (NIH).
The BIO-MIMETICS program will combine technologies developed at MIT, Draper Laboratory, MatTek and Zyoxel to create a versatile microfluidic platform that can incorporate up to 10 individual engineered human microphysiological organ system modules in an interacting circuit. The modules will be designed to mimic the functions of specific organ systems representing a broad spectrum of human tissues, including the circulatory, endocrine, gastrointestinal, immune, integumentary, musculoskeletal, nervous, reproductive, respiratory and urinary systems.
The goal of the program is to create a versatile platform capable of accurately predicting drug and vaccine efficacy, toxicity, and pharmacokinetics in preclinical testing. The BIO-MIMETICS team anticipates that the platform will be suitable for use in regulatory review, amenable to rapid translation to the biopharmaceutical research community, and adaptable for integration of future technologies (such as advances in stem cell technologies and personalized medicine).
Filed under science human body research preclinical testing technology BIO-MIMETICS
Soft autonomous earthworm robot at MIT
Earthworms creep along the ground by alternately squeezing and stretching muscles along the length of their bodies, inching forward with each wave of contractions. Snails and sea cucumbers also use this mechanism, called peristalsis, to get around, and our own gastrointestinal tracts operate by a similar action, squeezing muscles along the esophagus to push food to the stomach.
Now researchers at MIT, Harvard University and Seoul National University have engineered a soft autonomous robot that moves via peristalsis, crawling across surfaces by contracting segments of its body, much like an earthworm. The robot, made almost entirely of soft materials, is remarkably resilient: Even when stepped upon or bludgeoned with a hammer, the robot is able to inch away, unscathed.
Filed under autonomous robots computer science earthworm robot neuroscience robotics science nature
A group of researchers has developed some exciting new techniques for imaging neuronal and synaptic networks using the hard synchrotron x-rays provided by the U.S. Department of Energy Office of Science’s Advanced Photon Source (APS).
These techniques provide images with unprecedented detail and resolution, and open the door to three-dimensional tomographic reconstructions, a vital tool for studying the complex tree-like branching nature of neuronal networks.
Understanding intricate neuronal and synaptic networks, particularly in more complex mammalian brains, requires high-resolution mapping of large volumes of tissue, preferably in three dimensions in order to capture all the subtle structural details.
"Mapping neuron networks has been providing a very significant understanding of how the brain works," said Yeukwang Hwu of Academia Sinica in Taipei, Taiwan, lead author of the paper on this new study, which was published in the Journal of Physics D: Applied Physics.
Filed under science neuroscience brain neuron neuroimaging technology 3D reconstructions neural networks
John Rogers of the University of Illinois at Urbana-Champaign and colleagues have designed a flexible circuit that can be worn over the fingertips. It contains layers of gold electrodes just a few hundred nanometres thick, sandwiched between layers of polyimide plastic to form a “nanomembrane”. This is mounted on a finger-shaped tube of silicone rubber, allowing one side of the circuit to be in direct contact with the fingertips. On the other side, sensors can be added to measure pressure, temperature or electrical properties such as resistance.
People wearing the device receive electrotactile stimulation – a tingling sensation caused by a small voltage applied to the skin. The size of the voltage is controlled by the sensor and varies depending on the properties of the object being touched.
Surgical gloves are one potential application. Rogers, who worked with colleagues at Northwestern University in Evanston, Illinois, and Dalian University of Technology in China, says gloves fitted with the nanomembrane could sense the thickness or composition of tissue via its electrical properties. A surgeon could also whittle away at the tissue using a high-frequency alternating current supplied by a battery attached at the wrist and delivered via the nanomembrane itself, says Rogers.
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10 August 2012 by Helen Thomson
A woman born missing a finger and a thumb has grown them back – albeit as part of a phantom limb. This extraordinary occurrence shows that our brain contains a fully functional map of our body image, regardless of what our limbs actually look like.
The woman, RN, was born with just three fingers on her right hand. Aged 18, RN had the hand amputated after a car accident. She later began to feel that her missing limb was still present, and developed a “phantom” hand.
"But here’s the interesting thing," says Paul McGeoch at the University of California, San Diego. "Her phantom hand didn’t have three digits, it had five."
RN was aware of a full complement of fingers, but her phantom thumb and index finger were less than half the usual length.
With training using a mirror box trick – a tool that creates the visual illusion of two hands – McGeoch and V.S Ramachandran, also at San Diego, managed to extend her short phantom finger and thumb to normal length.
McGeoch says this study indicates that there is a hardwired representation in the brain of what the body should look like, regardless of how it actually appears in real life. It shows us more about the balance between the external and innate representations of a limb, he says.
"The presence of the deformed hand was suppressing the brain’s innate representation of her fingers which is why they appeared shorter, but after the hand was removed and the inhibition taken away, the innate representation kicks in again."
Matthew Longo at Birkbeck, University of London, says it is a fascinating case study. “It contributes to a growing literature suggesting that our conscious experience of our body is, at least in part, dependent on the intrinsic organisation of the brain, rather than a result of experience.”
Source: NewScientist
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