Brain imaging spots our abstract choices before we do

Brain imaging spots our abstract choices before we do:  Kreiman discovered that electrical activity in the supplementary motor area, involved in initiating movement, and in the anterior cingulate cortex, which controls attention and motivation, appeared up to 5 seconds before a volunteer was aware of deciding to press the button (Neuron, doi.org/btkcpz). This backed up earlier fMRI studies by John-Dylan Haynes of the Bernstein Center for Computational Neuroscience in Berlin, Germany, that had traced the origins of decisions to the prefrontal cortex a whopping 10 seconds before awareness...

If this kind of "mind-reading" is possible, a new study by Haynes, published this week and also presented at the meeting, suggests that it may not be restricted to decisions about moving a finger. Using fMRI, Haynes has found that the very brain areas involved in deciding to move are also active several seconds before a more abstract decision, like whether to add or subtract a series of numbers.

Precisely engineering 3-D brain tissues

Precisely engineering 3-D brain tissues: To mimic this architectural complexity in their engineered tissues, the researchers embedded a mixture of brain cells taken from the primary cortex of rats into sheets of hydrogel. They also included components of the extracellular matrix, which provides structural support and helps regulate cell behavior.

Those sheets were then stacked in layers, which can be sealed together using light to crosslink hydrogels. By covering layers of gels with plastic photomasks of varying shapes, the researchers could control how much of the gel was exposed to light, thus controlling the 3-D shape of the multilayer tissue construct.

This type of photolithography is also used to build integrated circuits onto semiconductors — a process that requires a photomask aligner machine, which costs tens of thousands of dollars. However, the team developed a much less expensive way to assemble tissues using masks made from sheets of plastic, similar to overhead transparencies, held in place with alignment pins.

The tissue cubes can be made with a precision of 10 microns, comparable to the size of a single cell body. At the other end of the spectrum, the researchers are aiming to create a cubic millimeter of brain tissue with 100,000 cells and 900 million connections.

A Carbon Microthread That Makes Contact with the Mind

A Carbon Microthread That Makes Contact with the Mind:  Researchers have come up with what they call a “stealthy neural interface” made from a single carbon fiber and coated with chemicals to make it resistant to proteins in the brain.

The new microthread electrode, designed to pick up signals from a single neuron as it fires, is only about 7 micrometers in diameter. That is the thinnest yet developed, and about 100 times as thin as the conventional metal electrodes widely used to study animal brains...


 He cautions, however, that it could be difficult to insert such fine, flexible electrodes into brain tissue, and to secure them. Schwartz notes that recordings broke down in many of the animals studied.

Company Aims to Cure Blindness with Optogenetics

Company Aims to Cure Blindness with Optogenetics: Retrosense is developing a treatment in which other cells in the retina could take the place of the rods and cones, cells which convert light into electrical signals. The company is targeting a group of neurons in the eye called ganglion cells. Normally, ganglion cells don't respond to light. Instead, they act as a conduit for electrical information sent from the retina's rods and cones...
Doctors would inject a non-disease causing virus into a patient's eye. The virus would carry the genetic information needed to produce the light-sensitive channel proteins in the ganglion cells. Normally, rods, cones, and other cells translate light information into a code of neuron-firing patterns that is then transmitted via the ganglion cells into the brain. Since Retrosense's therapy would bypass that information processing, it may require the brain to learn how to interpret the signals.

Artificial Jellyfish Swims Like the Real Thing

Artificial Jellyfish Swims Like the Real Thing: The duo and their colleagues stenciled out the ideal jellyfish shape on silicone, a material that would be sturdy but flexible, much like the jellyfish itself. They then coached rat muscle cells to grow in parallel bands on the silicone and encased the cells with a stretchy material called elastomer. To get their artificial jellyfish, or medusoid, swimming, the researchers submerged it in a salty solution and ran an electric current through the water, jump-starting the rat cells. The mimic propelled itself rapidly in the water, swimming as effectively as a real jellyfish, the researchers report online today in Nature Biotechnology.

Brain Chip Helps Quadriplegics Move Robotic Arms with Their Thoughts - Technology Review

Brain Chip Helps Quadriplegics Move Robotic Arms with Their Thoughts - Technology Review: The brain implant is a small array that's four millimeters on each side ("about the size of a baby aspirin," says Donoghue) with 96 hairlike electrodes extending from one side. The device sits on the surface of the brain, and the electrodes penetrate the arm-controlling region of the motor cortex by one millimeter. The implant records the impulses of dozens of neurons. A patient's intent to move generates these impulses, which are then transmitted to a computer that translates the patterns of electrical activity into commands that can control a robotic arm.

A Retinal Prosthetic Powered by Light

A Retinal Prosthetic Powered by Light: The device, designed by researchers at Stanford University in Palo Alto, California, combines infrared video-projection goggles with a small, wire-free chip implanted inside the retina.


A camera on the goggles transmits video to an image processor, which sends a signal back to infrared projection screens inside the goggles. Other researchers have tried to develop photovoltaic retinal implants in the past, but it didn't work. "The light that you get into the back of the retina at the equator on a sunny day is not enough to power a retinal implant," says James Loudin, a researcher at Stanford. So the Stanford system doesn't rely on the light that comes into the eye; it uses a projection system to make much more intense signals...

The infrared image is picked up by a compact array of photovoltaic pixels implanted right where the light-sensing cells would be in a healthy eye. Each pixel contains three infrared-sensitive diodes facing the inside of the eye. The diodes convert light into electricity that's pulsed out to the nerve cells by electrodes facing the back of the eye.

Telepathy machine reconstructs speech from brainwaves - New Scientist - New Scientist

Telepathy machine reconstructs speech from brainwaves: The team presented spoken words and sentences to 15 people having surgery for epilepsy or a brain tumour. Electrodes recorded neural activity from the surface of the superior and middle temporal gyri – an area of the brain near the ear that is involved in processing sound. From these recordings, Pasley's team set about decoding which aspects of speech were related to what kind of brain activity.

Tiny Fractal-Shaped Eye Implants Could Mimic Neurons, Allowing Blind Patients to See | Popular Science

Tiny Fractal-Shaped Eye Implants Could Mimic Neurons, Allowing Blind Patients to See | Popular Science: His solution is to embed a nanoscale clump of material onto the photodiode, which would self-assemble into fractal shapes. The clump would be deposited onto a photodiode using an inert gas. Eye surgeons would implant the fractal-enhanced devices inside the eyes of patients who have lost their vision, and the improved neuron interface would enable more light information to be relayed to the optic nerve. It would work with almost 100 percent efficiency, according to a University of Oregon news release.

Squishy Bio-Electronics Could Make Better Implants and Brain-Machine Interface Controls | Popular Science

Squishy Bio-Electronics Could Make Better Implants and Brain-Machine Interface Controls | Popular Science: A pair of grad students at North Carolina State University presented a paper last week describing a quasi-liquid diode whose electrodes are made of a gallium-indium alloy that is liquid at room temperature. Two hydrogel films are sandwiched between the electrodes — one is doped with an acid and the other holds an alkaline compound.
The interface between the electrodes develops a thin coating of gallium oxide, which creates resistance, as IEEE Spectrum explains. The electrode with the alkaline substance suppresses the formation of this skin. So, applying voltage changes the the thickness of this gallium oxide “skin” — negative voltage makes the oxide thinner, lowering the device’s resistance, and a positive voltage makes it thicker, producing greater resistance.

Technology Review: An Implantable Antenna

Technology Review: An Implantable Antenna: "Omenetto and his colleague Richard Averitt, associate professor of physics at Boston University, used similar principles to create a metamaterial that's responsive not to visible light, but rather to frequencies further down the electromagnetic spectrum, within the terahertz range. Not coincidentally, proteins, enzymes, and chemicals in the body are naturally resonant at terahertz frequencies, and, according to Averitt, each biological agent has its own terahertz "signature."

Terahertz science is a new and growing field, and several research groups are investigating specific protein "T-ray" signatures. A silk metamaterial antenna could someday pick up these specific signals and then send a wireless signal to a computer, to report on chemical levels and monitor disease.

To engineer the responsive end of such an antenna, the team first created a biocompatible base by boiling down silk and pouring the liquid solution into a centimeter-square film. The researchers then sprayed gold onto the silk film, using tiny stencils to create different patterns all along the film. Each area of the film responds to a different terahertz frequency depending on the shape of the gold pattern. The team then wrapped the patterned film around a capsule to form an antenna."