More than 100 hours of MIR scanning has generated an image of a whole human brain with unprecedented level of detail. Massachusetts General Hospital researchers and their colleagues used a 7 Tesla MRI machine, recently approved by the FDA, to scan the donated brain from a 58-year-old-woman. The image shows detail down to .1 millimeter. From Science News:
Before the scan began, researchers built a custom spheroid case of urethane that held the brain still and allowed interfering air bubbles to escape. Sturdily encased, the brain then went into a powerful MRI machine called a 7 Tesla, or 7T, and stayed there for almost five days of scanning...
Researchers can’t get the same kind of resolution on brains of living people. For starters, people couldn’t tolerate a 100-hour scan. And even tiny movements, such as those that come from breathing and blood flow, would blur the images...
These (new kinds of) detailed brain images could hold clues for researchers trying to pinpoint hard-to-see brain abnormalities involved in disorders such as comas and psychiatric conditions such as depression.
"7 Tesla MRI of the ex vivo human brain at 100 micron resolution" (bioRxiv.org)
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A new study suggests that humans can subconsciously sense Earth's magnetic field. While this capability, called magnetoreception, is well known in birds and fish, there is now evidence that our brains are also sensitive to magnetic fields. The researchers from Caltech and the University of Tokyo measured the brainwaves of 26 participants who were exposed to magnetic fields that could be manipulated. Interestingly, the brainwaves were not affected by upward-pointing fields. From Science News:
Participants in this study, who all hailed from the Northern Hemisphere, should perceive downward-pointing magnetic fields as natural, whereas upward fields would constitute an anomaly, the researchers argue. Magnetoreceptive animals are known to shut off their internal compasses when encountering weird fields, such as those caused by lightning, which might lead the animals astray. Northern-born humans may similarly take their magnetic sense “offline” when faced with strange, upward-pointing fields...
Even accounting for which magnetic changes the brain picks up, researchers still don’t know what our minds might use that information for, (Caltech neurobiologist and geophysicist Joseph) Kirschvink says. Another lingering mystery is how, exactly, our brains detect Earth’s magnetic field. According to the researchers, the brain wave patterns uncovered in this study may be explained by sensory cells containing a magnetic mineral called magnetite, which has been found in magnetoreceptive trout as well as in the human brain.
"Transduction of the Geomagnetic Field as Evidenced from Alpha-band Activity in the Human Brain" (eNeuro)
"Evidence for a Human Geomagnetic Sense" (Caltech) Read the rest
"Consciousness is what allows us to be aware of both our surroundings and our own inner state." In the first of a three part video series, "Kruzgesagt - In a Nutshell" examines "how unaware things come aware." Stay tuned for theories of consciousness that of course may be as much about philosophy as they are neuroscience.
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Scientists Lior Appelbaum and David Zada in Israel publish new proof that sleep serves to help our brains repair damage. Read the rest
ASAP Science provides some excellent tips for intensive, last-minute studying of just about any subject where you need to remember a lot of information. The video covers a lot of ground, from memory palaces and cortisol to metacognition to other things I can't remember because I didn't study enough.
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Teams of researchers are developing sesame seed-size neuro-implants that detect brain activity that signals depression and then deliver targeted electrical zaps to elevate your mood. It's very early days in the science and technology but recent studies suggest that we're on the path. Links to scientific papers below. Fortunately, the goal is to develop tools and a methodology more precise than the horrifically blunt "shock therapy" of last century. From Science News:
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DARPA, a Department of Defense research agency, is funding (Massachusetts General Hospital's research on new brain stimulation methods) plus work at UCLA on targeted brain stimulation. Now in its fifth and final year, the (DARPA) project, called SUBNETS, aims to help veterans with major depression, post-traumatic stress, anxiety and other psychiatric problems. “It is extremely frustrating for patients to not know why they feel the way they do and to not be able to correct it,” Justin Sanchez, the director of DARPA’s Biological Technologies Office, said in a Nov. 30 statement. “We owe them and their families better options.”
These next-generation systems, primarily being developed at UCSF and Massachusetts General Hospital, might ultimately deliver. After detecting altered brain activity that signals a looming problem, these devices, called closed-loop stimulators, would intervene electrically with what their inventors hope is surgical precision.
In contrast to the UCSF group, Widge, who is at the University of Minnesota in Minneapolis, and his collaborators don’t focus explicitly on mood. The researchers want to avoid categorical diagnoses such as depression, which they argue can be imprecise.
Anna Abraham literally wrote the book on creativity and the brain. The Leeds Beckett University psychology professor is the author of a new textbook titled The Neuroscience of Creativity. From an interview with Abraham by psychologist Scott Barry Kaufman in Scientific American:
SBK: Why does the myth of the “creative right brain” still persist? Is there any truth at all to this myth?
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AA: Like most persistent myths, even if some seed of truth was associated with the initial development of the idea, the claim so stated amounts to a lazy generalization and is incorrect. The brain’s right hemisphere is not a separate organ whose workings can be regarded in isolation from that of the left hemisphere in most human beings. It is also incorrect to conclude that the left brain is uncreative. In fact even the earliest scholars who explored the brain lateralization in relation to creativity emphasized the importance of both hemispheres. Indeed this is what was held to be unique about creativity compared to other highly lateralized psychological functions. In an era which saw the uncovering of the dominant involvement of one hemisphere over the other for many functions, and the left hemisphere received preeminent status for its crucial role in complex functions like language, a push against the tide by emphasizing the need to also recognize the importance of the right hemisphere for complex functions like creativity somehow got translated over time into the only ‘creative right brain’ meme. It is the sort of thing that routinely happens when crafting accessible sound bites to convey scientific findings.
There's scientific truth to the saying that you never forget how to ride a bike. Even if you can't remember phone numbers, birthdays, or where the hell you parked your car, it's likely that even if you haven't been on a bicycle in decades, you can climb on and ride away just fine. Why? Neuropsychologist Boris Suchan of Germany's Ruhr University Bochum lays it out as best we know in Scientific American:
As it turns out, different types of memories are stored in distinct regions of our brains. Long-term memory is divided into two types: declarative and procedural.
There are two types of declarative memory: Recollections of experiences such as the day we started school and our first kiss are called episodic memory. This type of recall is our interpretation of an episode or event that occurred. Factual knowledge, on the other hand, such as the capital of France, is part of semantic memory. These two types of declarative memory content have one thing in common—you are aware of the knowledge and can communicate the memories to others.
Skills such as playing an instrument or riding a bicycle are, however, anchored in a separate system, called procedural memory. As its name implies, this type of memory is responsible for performance...
According to one idea, in the regions where movement patterns are anchored fewer new nerve cells may be formed in adults. Without this neurogenesis, or continuous remodeling in those regions, it’s less likely for those memories to get erased.
"Why Don’t We Forget How to Ride a Bike? Read the rest
Now seems like a fine time to read this Scientific American article titled The Art of Lying by Theodor Schaarschmidt. According to a study conducted by UC Santa Barbara psychologist Bella M. DePaulo and referenced in the article, people make up around two stories every day. Apparently, children "initially have difficulty formulating believable lies, but proficiency improves with age. Young adults between 18 and 29 do it best. After about the age of 45, we begin to lose this ability." From Scientific American:
Current thinking about the psychological processes involved in deception holds that people typically tell the truth more easily than they tell a lie and that lying requires far more cognitive resources. First, we must become aware of the truth; then we have to invent a plausible scenario that is consistent and does not contradict the observable facts. At the same time, we must suppress the truth so that we do not spill the beans—that is, we must engage in response inhibition. What is more, we must be able to assess accurately the reactions of the listener so that, if necessary, we can deftly produce adaptations to our original story line. And there is the ethical dimension, whereby we have to make a conscious decision to transgress a social norm. All this deciding and self-control implies that lying is managed by the prefrontal cortex—the region at the front of the brain responsible for executive control, which includes such processes as planning and regulating emotions and behavior.
"The Art of Lying" (Scientific American)
image: screenshot of Pinocchio film trailer, public domain
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Based on a new study of the safety and abuse potential of psilocybin, the hallucinogenic drug in magic mushrooms, Johns Hopkins University School of Medicine researchers recommend that "psilocybin should be re-categorized from a schedule I drug—one with no known medical potential—to a schedule IV drug such as prescription sleep aids, but with tighter control."
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Neurologist Steven Laureys is an expert on the mysteries of consciousness. A researcher and clinician at the Belgian National Fund of Scientific Research he's known for testing comatose patients for any hidden signs of consciousness. From Scientific American's interview with Laureys:
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So how is it possible to study something as complex as consciousness?
There are a number of ways to go about it, and the technology we have at our disposal is crucial in this regard. For example, without brain scanners we would know much, much less than we now do. We study the damaged brains of people who have at least partially lost consciousness. We examine what happens during deep sleep, when people temporarily lose consciousness. We’ve also been working with Buddhist monks because we know that meditation can trigger alterations in the brain; connections that are important in the networks involved in consciousness show changes in activity. Hypnosis and anesthesia can also teach us a great deal about consciousness. In Lige, surgeons routinely operate on patients under hypnosis ( including Queen Fabiola of Belgium). Just as under anesthesia, the connections between certain brain areas are less active under hypnosis. And finally, we are curious to understand what near-death experiences can tell us about consciousness. What does it mean that some people feel they are leaving their bodies, whereas others suddenly feel elated?
Patients are brought to Lige from all over Europe to undergo testing. How do you determine whether they are conscious?
Well, of course, the physician will say, “Squeeze my hand”—but this time while the patient is in a brain scanner.
We often unconsciously mirror the behavior of people we interact with. This can include mirroring posture, gestures, and voice patterns. A recent paper in Current Biology reports that we can mirror a smile based on speech alone, and even do so without actually detecting the smile.
The researchers applied a signal processing technique for altering recorded speech under a neutral mouth position to what it would have sounded like had the speaker been smiling. They played 60 such recordings (some manipulated, some not) to 35 subjects, and asked them to judge whether the speaker was smiling. The researchers also measured the responses of two subject muscle groups while listening, the zygomatic (smiling) muscles and the corrugator (frowning) muscles.
When the subjects correctly reported neutral expression or smiling in the speech, both of their muscle groups accurately mirrored the speech while listening (e.g., for smiling speakers, zygomatic tensing and corrugator relaxing). Interestingly, even when the subjects were wrong, their zygomatic muscles still mirrored correctly. This was not true for the corrugators, which instead reflected the subjects' report.
Our mirroring capabilities go well beyond what we see, or even perceive. Read the rest
Patrick Costello (previously) writes, "I had to go through a 25 hr EEG, but I didn't let the wires glued to my head stop me from posting my weekly frailing banjo workshop."
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A team of computer scientists, psychologists and neuroscientists used eye-tracking and fMRI to measure how users perceived security warnings, such as warnings about app permissions and browser warnings about insecure pages and plugin installations.
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MIT 9.11, "The Human Brain," is taught by Nancy Kanwisher, the Walther A. Rosenblith Professor of Cognitive Neuroscience at the Department of Brain & Cognitive Sciences, MIT; Kanwisher is an engaging and lively science communicator and has posted videos of the complete course lecture series for your perusal; her own speciality is neuroimaging, and the introductory lecture is a fascinating (and, at times, terrifying) tale of her colleague's neurological condition and what she learned from it. (via Four Short Links)
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Deep brain stimulators -- pacemaker-like implants that deliver electrical impulses to specific regions in the brain -- are common treatments for Parkinson's and other neurological disorders. It's known that strong electromagnetic fields from the likes of ham radio antennae and arc welders can damage the devices. Now, researchers report the case of a 66-year-old woman whose deep brain stimulator was knocked out when lightning hit her apartment. Fortunately, the lightning shut off the device without damaging her brain.
“The patient was not charging the battery of her IPG (implantable pulse generator) during the event, and the recharger for the IPG was disconnected from the power supply during the storm," the researchers wrote. "The recharger and IPG were therefore not destroyed. The patient realized that something was wrong only 1 hour after the storm subsided, when the dystonic tremor in her neck reappeared.”
"Lightning may pose a danger to patients receiving deep brain stimulation: case report" (Journal of Neuroscience via Mysterious Universe) Read the rest
A group of Belgian academic security researchers from KU Leuwen have published a paper detailing their investigation into improving the security of neurostimulators: electrical brain implants used to treat chronic pain, Parkinson's, and other conditions.
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