In Isaac Asimov’s 1950 short story collection I, Robot, intelligent robots with positronic brains exist alongside humans. Unlike conventional computer hardware, the word positronic implies that electrical current is carried in the wires of these robots’ brains by positrons, the antimatter counterpart of the familiar electron. Though the advantage of antimatter here is anyone’s guess, the stories of I, Robot may have introduced the positron to the public. And as bizarre as Asimov’s fantasy sounds, neuroimaging has given the term “positronic brain” yet another meaning.
Benjamin Franklin once quipped: ‘There are three things extremely hard: steel, a diamond, and to know oneself.’ Every decision we make, from pinpointing the source of a faint sound to choosing a new job, comes with a degree of confidence that we have made the right call. If confidence is sufficiently low, we might change our minds and reverse our decision. Now scientists are using these choice reversals to study the first inklings of self-knowledge. Changes of mind, it turns out, reflect a precisely tuned process for monitoring our stream of thoughts.Continue reading
To make a working nervous system, only two forces are necessary: excitation and inhibition. Continue reading
Brain stimulation might sound like some Frankensteinian demonstration from a Victorian science fair. But in reality, it is a contemporary technique making a huge impact in neuroscience by addressing a longstanding limitation of traditional methods for investigating human brain function. Such techniques, like EEG and fMRI, can only be used to infer the effects of a stimulus or task on brain activity, and not vice versa. For example, a scientist might use EEG to study the effect of a task like arm movement on brain activity, but how can one study the effect of brain activity on arm movement?Continue reading
Marine mammals, such as dolphins, whales, and porpoises, spend their entire lives at sea. Like us, they need to breathe, avoid danger, and care for their young. Like us, they need to sleep, which — for us — involves almost total unconsciousness and paralysis. So how do these marine mammals not drown when they sleep?Continue reading
We have someone new joining our team! She is a neuroscience PhD student at the University of Iowa, and she studies speech perception – but let’s let the animation she created explain exactly what that means:Continue reading
If you grew up with siblings, it is likely that you have heard the phrase, ”Imitation is the sincerest form of flattery.” However, it wasn’t until a groundbreaking finding in the 1990s that the neural correlate to imitation was discovered in a class of neurons called mirror neurons. Continue reading
What are brain waves? It’s no wonder the term sounds like science fiction. In the 1920s, a German psychiatrist embarked on a highly personal quest to discover the supposed medium of telepathy. By placing electrodes on the human scalp, Hans Berger found waves of electrical brain activity using a tool called electroencephalography, or EEG. Physicists had recently shown that electromagnetic waves could propagate through space to carry information. If the brain had its own waves, could they transmit thoughts to others like a radio broadcast?Continue reading
Who hasn’t wanted to snap their fingers and dive into the pages of the gorgeous places featured in National Geographic? Caught in a miserable physics exam that you haven’t studied for? No problem, with teleportation you can be whisked away to an expedition to Mars or an Australian beach. Afraid of heights but curious about skydiving? Immersion into an artificial, computer-simulated environment can emulate the look and feel of the real thing without any danger or risk. Virtual reality enables the military to train pilots to fly planes without leaving the safety of the base. Virtual environments are almost limitless in scope, allowing researchers to study complex motor behaviors. These virtual environments are often experienced with a head mounted display that allows the participant to move freely within the perceived environment — be it a pre-historic landscape or a lunar landing.Continue reading
It’s a lazy Sunday afternoon. Professor Freeman is enjoying the Southern California weather on Professor Domino’s patio.
Domino: Will it be Coke or Pepsi, Dr. Freeman?
Freeman: That’s an easy choice, Dr. Domino.Continue reading
Last month, astronomers announced the prediction of a new giant planet in our solar system dubbed Planet IX, a genuine ninth planet with ten times the mass of Earth. The announcement lead to some confusion on the Internet as to the whether the planet had actually been discovered. In fact, no direct observation of this planet has been made. Rather, the planet has been predicted by a model, a simplified description of a system which often incorporates hypothetical elements to explain the variance in data. Because many models use equations to describe a system, a model can often be thought of as a theory with a mathematical backbone.Continue reading
People like simplicity. Each decade, corporate logos grow progressively minimalistic, pop songs use ever simpler melodies, and visual art embraces simpler compositions, as Monet gives way to Picasso and Picasso gives way Rothko. This zeitgeist, summarized as “simplicity is the ultimate sophistication,” shapes our perceptions of physiology in interesting ways. The thumping of a beating heart is often celebrated as nature’s beautifully simple rhythm. Listening through a doctor’s stethoscope, one expects any deviation from perfect rhythmicity to be an omen of disease.Continue reading