Now Playing Tracks

neuromorphogenesis:

The Future of Brain Implants

What would you give for a retinal chip that let you see in the dark or for a next-generation cochlear implant that let you hear any conversation in a noisy restaurant, no matter how loud? Or for a memory chip, wired directly into your brain’s hippocampus, that gave you perfect recall of everything you read? Or for an implanted interface with the Internet that automatically translated a clearly articulated silent thought (“the French sun king”) into an online search that digested the relevant Wikipedia page and projected a summary directly into your brain?

Science fiction? Perhaps not for very much longer. Brain implants today are where laser eye surgery was several decades ago. They are not risk-free and make sense only for a narrowly defined set of patients—but they are a sign of things to come.

Unlike pacemakers, dental crowns or implantable insulin pumps, neuroprosthetics—devices that restore or supplement the mind’s capacities with electronics inserted directly into the nervous system—change how we perceive the world and move through it. For better or worse, these devices become part of who we are.

Neuroprosthetics aren’t new. They have been around commercially for three decades, in the form of the cochlear implants used in the ears (the outer reaches of the nervous system) of more than 300,000 hearing-impaired people around the world. Last year, the Food and Drug Administration approved the first retinal implant, made by the company Second Sight.

Both technologies exploit the same principle: An external device, either a microphone or a video camera, captures sounds or images and processes them, using the results to drive a set of electrodes that stimulate either the auditory or the optic nerve, approximating the naturally occurring output from the ear or the eye.

Another type of now-common implant, used by thousands of Parkinson’s patients around the world, sends electrical pulses deep into the brain proper, activating some of the pathways involved in motor control. A thin electrode is inserted into the brain through a small opening in the skull; it is connected by a wire that runs to a battery pack underneath the skin. The effect is to reduce or even eliminate the tremors and rigid movement that are such prominent symptoms of Parkinson’s (though, unfortunately, the device doesn’t halt the progression of the disease itself). Experimental trials are now under way to test the efficacy of such “deep brain stimulation” for treating other disorders as well.

Electrical stimulation can also improve some forms of memory, as the neurosurgeon Itzhak Fried and his colleagues at the University of California, Los Angeles, showed in a 2012 article in the New England Journal of Medicine. Using a setup akin to a videogame, seven patients were taught to navigate a virtual city environment with a joystick, picking up passengers and delivering them to specific stores. Appropriate electrical stimulation to the brain during the game increased their speed and accuracy in accomplishing the task.

But not all brain implants work by directly stimulating the brain. Some work instead by reading the brain’s signals—to interpret, for example, the intentions of a paralyzed user. Eventually, neuroprosthetic systems might try to do both, reading a user’s desires, performing an action like a Web search and then sending the results directly back to the brain.

How close are we to having such wondrous devices? To begin with, scientists, doctors and engineers need to figure out safer and more reliable ways of inserting probes into people’s brains. For now, the only option is to drill small burr-holes through the skull and to insert long, thin electrodes—like pencil leads—until they reach their destinations deep inside the brain. This risks infection, since the wires extend through the skin, and bleeding inside the brain, which could be devastating or even fatal.

External devices, like the brainwave-reading skull cap made by the company NeuroSky (marketed to the public as “having applications for wellness, education and entertainment”), have none of these risks. But because their sensors are so far removed from individual neurons, they are also far less effective. They are like Keystone Kops trying to eavesdrop on a single conversation from outside a giant football stadium.

Read More

neuromorphogenesis:

Reflections on Dreaming and Consciousness

The function of sleep is to rest and restore the organism to be at its best to take on the challenges of living during the next day. During sleep, the muscles undergo rest and de-enervation. The biochemical waste products of muscle activity are eliminated and detoxified. Metabolically, all the organ systems do their night’s work—digestion, detoxification, cleansing waste products, cellular repair, cell growth, immunological activity, etc. A central arena for the work of sleep is for the rest and restoration of our consciousness. In order for consciousness to be at its best and open to take on tomorrow’s challenges, it must digest and detoxify conflicts stirred during the previous day and recent past. This is the work of dreaming.

Consciousness in waking life operates as a kind of top down functioning. Organized as an invisible play, established in early childhood, it informs how we filter and process the world. Conflicts that are stirred during the day, which resonate with the warp of our play inside, then need to be digested to leave us open to take on the next day. Dreams do the digestion work during sleep for whatever is generated during the day as it resonates with our inner character. Consciousness operates on the level of people and feeling. What are the conflicts that are addressed by dreaming? The issues that may occupy the dream stage are combats, quests, challenges, boredoms, wishes,
hopes, curiosities, pain, disappointments, sexual interests and stimulations, fantasies, competitions, fears, anxieties, cruelty, sadism, humiliations, sufferings, abuse, deprivations, traumas, envies, jealousies, sadnesses, and otherwise the full panoply of life’s dramas, engagements, and relationship adventures.

The restorative processes of the organism during sleep operate in their appropriate contexts. With regard to cellular metabolism, digestion operates in the molecular realm. Emotional conflict, which operates in the realm of people and feeling, gets digested in its comparable world, a dream of people and feeling. The function of dreaming is consonant with the overall function of sleep—to restore the brain-body so it can be free and flexible to take on the next day in the most optimal way. Consequently, there is a special sleep state devoted to dreaming, REM sleep, whose function is to restore our consciousness. In REM sleep, we are in a brain-body trance state. The attention of consciousness is withdrawn from reality. Consciousness is no longer oriented through the senses or the body. Consciousness recedes from our striated muscles, so we are in a state of paralysis. Muscle tone is at its lowest ebb. Likewise, it recedes significantly from our senses so that we are not oriented by reading reality. The eyes, no longer seeing the outside world, dart back and forth—with their Rapid Eye Movements—as we see a dream. If any of the senses gets stimulated beyond a certain threshold—a loud noise, a strong light, a strong touch, even a strong smell or taste—we shift trance states back to waking.

Consciousness, no longer operative in the theater of reality, now operates in a living theater of the brain, doing its sleep work. No longer tied to reality, the curtain is lifted on this inner theater. A drama, triggered by the events of the day, is now onstage. Untethered to reality, it writes its own play, giving us a window into the unadulterated nature of consciousness itself. Inner dramas triggered by the day’s conflicts are the stuff of dreams. It is through the enactments of the dream story that consciousness does its sleep work.

Since dreams are about emotional conflicts, the feeling centers in the brain are central in the construction of all aspects of dream creation. Consciousness, in dreams, is not just a reductive brain rehash. Dreams are an alive, creative production of consciousness. Dream enactments take place in the living moment, as do the productions of waking consciousness. It is also essential to realize that the actual work of a dream is enacted in sleep with no reference to wakefulness at all. Our dreams are not dreamed to be seen by our waking selves. They are not a production to be shown in your local movie theater, on HBO, or on YouTube. They are purely intended to be shown on the brain’s projection screen in sleep. The brain routinely does its REM sleep work unremembered.

We remember only a tiny fraction of dreams. In fact, we dream about the same stirred conflicts five times over the course of the night. Although remembered dreams are, in fact, useful in therapy, and can provide eureka moments for us, this is not their purpose or function. The happenstance that we remember a dream is an unintended by-product of a trance shift on awakening. If the purpose of dreams were for us to acquire information about our waking selves, remembering far less than one percent of them in some seemingly secret code would be woefully inefficient.

Good night*

We make Tumblr themes