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Category: Neuroscience

The act of smelling

The act of smelling

Jude Stewart writes: If all our genius lies in our nostrils, as Nietzsche remarked, the nose is an untrained genius, brilliant but erratic. The human nose can detect a dizzying array of smells, with a theoretical upper limit of one trillion smells—yet many of us are incapable of describing these smells in words more precise than smelly and fragrant. Our auditory and visual receptors offer little mystery—they were mapped and explained by scientists many decades ago—but human olfactory receptors were…

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How memories persist where bodies and even brains do not

How memories persist where bodies and even brains do not

Thomas R Verny writes: I began exploring the concept of cellular memory – the idea that memory can be stored outside the brain, in all the body’s cells – after reading an article on Reuters headlined ‘Tiny Brain No Obstacle to French Civil Servant’ in 2007. It seems that a 44-year-old French man had gone to hospital complaining of a mild weakness in his left leg. Doctors learned that the patient ‘had a shunt inserted into his head to drain…

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Is there a symmetry between metacognition and mindreading?

Is there a symmetry between metacognition and mindreading?

Stephen M Fleming writes: In 1978, David Premack and Guy Woodruff published a paper that would go on to become famous in the world of academic psychology. Its title posed a simple question: does the chimpanzee have a theory of mind? In coining the term ‘theory of mind’, Premack and Woodruff were referring to the ability to keep track of what someone else thinks, feels or knows, even if this is not immediately obvious from their behaviour. We use theory…

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The easy part of the hard problem of consciousness

The easy part of the hard problem of consciousness

Tam Hunt writes: How does consciousness arise? What might its relationship to matter be? And why are some things conscious while others apparently aren’t? These sorts of questions, taken together, make up what’s called the “hard problem” of consciousness, coined some years ago by the philosopher David Chalmers. There is no widely accepted solution to this. But, fortunately, we can break the problem down: If we can tackle what you might call the easy part of the hard problem, then…

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How computationally complex is a single neuron?

How computationally complex is a single neuron?

Allison Whitten writes: Our mushy brains seem a far cry from the solid silicon chips in computer processors, but scientists have a long history of comparing the two. As Alan Turing put it in 1952: “We are not interested in the fact that the brain has the consistency of cold porridge.” In other words, the medium doesn’t matter, only the computational ability. Today, the most powerful artificial intelligence systems employ a type of machine learning called deep learning. Their algorithms…

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The brain doesn’t work the way you think it does

The brain doesn’t work the way you think it does

Jordana Cepelewicz writes: Neuroscientists are the cartographers of the brain’s diverse domains and territories — the features and activities that define them, the roads and highways that connect them, and the boundaries that delineate them. Toward the front of the brain, just behind the forehead, is the prefrontal cortex, celebrated as the seat of judgment. Behind it lies the motor cortex, responsible for planning and coordinating movement. To the sides: the temporal lobes, crucial for memory and the processing of…

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Animals count and use zero. How far does their number sense go?

Animals count and use zero. How far does their number sense go?

Jordana Cepelewicz writes: An understanding of numbers is often viewed as a distinctly human faculty — a hallmark of our intelligence that, along with language, sets us apart from all other animals. But that couldn’t be further from the truth. Honeybees count landmarks when navigating toward sources of nectar. Lionesses tally the number of roars they hear from an intruding pride before deciding whether to attack or retreat. Some ants keep track of their steps; some spiders keep track of…

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Do wild animals get PTSD? Scientists probe its evolutionary roots

Do wild animals get PTSD? Scientists probe its evolutionary roots

By Sharon Levy, Knowable Magazine Every few years, snowshoe hare numbers in the Canadian Yukon climb to a peak. As hare populations increase, so do those of their predators: lynx and coyotes. Then the hare population plummets and predators start to die off. The cycle is a famous phenomenon among ecologists and has been studied since the 1920s. In recent years, though, researchers have come to a startling conclusion: Hare numbers fall from their peak not just because predators eat…

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Why your sleeping brain replays new rewarding experiences

Why your sleeping brain replays new rewarding experiences

Jim Davies writes: During this Olympics, I’ve been rooting for Kelleigh Ryan, who is on the women’s foil team. She’s from Ottawa, where I live. Whenever she scored a point, she’d emit a victory scream, probably feeling a rush of pleasure. Watching her on television, I did, too. Getting better at something involves emotion. When we do well, we have good feelings—pride, pleasure, excitement—and these emotions help reinforce whatever behaviors we just engaged in. Similarly, the pain of failure makes…

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New research finds time spent among trees might help kids’ brains grow and develop

New research finds time spent among trees might help kids’ brains grow and develop

Science Alert reports: As a child grows and develops, the neurons in their brain are said to branch like trees. Being around this very type of foliage could actually help the process along. A long-term study among 3,568 students in London, between the ages of 9 and 15, has found those kids who spent more time near woodlands showed improved cognitive performance and mental health in adolescence. On the other hand, other natural environments, like grasslands or lakes and rivers,…

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Neurons unexpectedly encode information in the timing of their firing

Neurons unexpectedly encode information in the timing of their firing

Elena Renken writes: For decades, neuroscientists have treated the brain somewhat like a Geiger counter: The rate at which neurons fire is taken as a measure of activity, just as a Geiger counter’s click rate indicates the strength of radiation. But new research suggests the brain may be more like a musical instrument. When you play the piano, how often you hit the keys matters, but the precise timing of the notes is also essential to the melody. “It’s really…

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An artificial network kept on the ‘edge of chaos’ acts much like a human brain

An artificial network kept on the ‘edge of chaos’ acts much like a human brain

Science Alert reports: Researchers have demonstrated how to keep a network of nanowires in a state that’s right on what’s known as the edge of chaos – an achievement that could be used to produce artificial intelligence (AI) that acts much like the human brain does. The team used varying levels of electricity on a nanowire simulation, finding a balance when the electric signal was too low when the signal was too high. If the signal was too low, the…

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Researchers identify brain circuit for spirituality

Researchers identify brain circuit for spirituality

Brigham and Women’s Hospital reports: More than 80 percent of people around the world consider themselves to be religious or spiritual. But research on the neuroscience of spirituality and religiosity has been sparse. Previous studies have used functional neuroimaging, in which an individual undergoes a brain scan while performing a task to see what areas of the brain light up. But these correlative studies have given a spotty and often inconsistent picture of spirituality. A new study led by investigators…

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‘Time cells’ identified in our brains encode the flow of time, scientists say

‘Time cells’ identified in our brains encode the flow of time, scientists say

Science Alert reports: How does the human brain keep track of the order of events in a sequence? New research suggests that ‘time cells’ – neurons in the hippocampus thought to represent temporal information – could be the glue that sticks our memories together in the right sequence so that we can properly recall the correct order in which things happened. Evidence for these kinds of sequence-tracking time cells was previously found in rats, where specific neuron assemblies are thought…

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Same or different? The question flummoxes neural networks

Same or different? The question flummoxes neural networks

John Pavlus writes: The first episode of Sesame Street in 1969 included a segment called “One of These Things Is Not Like the Other.” Viewers were asked to consider a poster that displayed three 2s and one W, and to decide — while singing along to the game’s eponymous jingle — which symbol didn’t belong. Dozens of episodes of Sesame Street repeated the game, comparing everything from abstract patterns to plates of vegetables. Kids never had to relearn the rules….

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Could mitochondria be the key to a healthy brain?

Could mitochondria be the key to a healthy brain?

Diana Kwon writes: Long before the earliest animals swam through the water-covered surface of Earth’s ancient past, one of the most important encounters in the history of life took place. A primitive bacterium was engulfed by our oldest ancestor — a solo, free-floating cell. The two fused to form a mutually beneficial relationship that has lasted more than a billion years, with the latter providing a safe, comfortable home and the former becoming a powerhouse, fueling the processes necessary to…

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