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Category: neuroscience – Page 356

Phantom touch: Virtual reality can induce a mysterious tactile illusion, scientists find

In a new study published in Scientific Reports, researchers have uncovered a phenomenon known as the “phantom touch illusion,” where individuals experience tactile sensations without actual physical contact in a virtual reality (VR) setting. This intriguing discovery raises questions about how the brain processes sensory information.

Previous research has shown that our nervous system can differentiate between self-generated touch and touch from external sources, a process often described as tactile gating. This ability helps us understand our interactions with the world around us.

When you perform an action that results in self-touch, your brain anticipates this contact. It knows that the sensation is a result of your own movement. Because of this anticipation, the brain ‘turns down the volume’ on the sensory response. Essentially, it partially “cancels” or gates out the sensation because it’s expected and self-generated. This is why you can’t effectively tickle yourself – your brain knows the touch is coming and reduces the response.

A cluster of genetically defined brainstem neurons involved in the production and modulation of sounds

Humans and other mammals can produce a wide range of sounds, while also modulating their volume and pitch. These sounds, also known as mammalian vocalizations, play a central role in communication between both animals of the same and of different species.

Researchers at Stanford University School of Medicine recently carried out a study aimed at better understanding the neural mechanisms underpinning the production and modulation of mammal vocalizations. Their paper, published in Nature Neuroscience, identifies a neural circuit and a set of genetically defined in the that play a key role in the production of .

“All mammals, including humans, vocalize by pushing air past the vocal cords of the larynx, which vibrate to produce sound,” Avin Veerakumar, co-author of the paper, told Medical Xpress.

Serotonin Shortage: Tracing the Early Warning Signs of Alzheimer’s

PET scans of people with mild cognitive impairment detected lower levels of serotonin, the brain chemical associated with positive mood, compared to those without it.

Comparing PET scans of more than 90 adults with and without mild cognitive impairment (MCI), Johns Hopkins Medicine researchers say relatively lower levels of the so-called “happiness” chemical, serotonin, in parts of the brain of those with MCI may play a role in memory problems including Alzheimer’s disease.

The findings, recently published in the Journal of Alzheimer’s Disease, lend support to growing evidence that measurable changes in the brain happen in people with mild memory problems long before an Alzheimer’s diagnosis, and may offer novel targets for treatments to slow or stop disease progression.

New Research Sheds Light on Origins of Social Behaviors

Male fruit flies typically display antisocial behavior towards other males, preferring the company of females, which they identify through chemical receptors. However, recent studies by biologists at Cornell University indicate that the visual system of fruit flies plays a significant role in their social interactions.

This discovery provides new insights into the potential roots of varied social behaviors in humans, including those associated with conditions like bipolar disorder and autism.

The paper was recently published in Current Biology.

Brain implants revive cognitive abilities long after traumatic brain injury in clinical trial

In 2001, Gina Arata was in her final semester of college, planning to apply to law school, when she suffered a traumatic brain injury in a car accident. The injury so compromised her ability to focus she struggled in a job sorting mail.

“I couldn’t remember anything,” said Arata, who lives in Modesto with her parents. “My dropped, so I’d trip over things all the time. I was always in car accidents. And I had no filter—I’d get pissed off really easily.”

Her parents learned about research being conducted at Stanford Medicine and reached out; Arata was accepted as a participant. In 2018, physicians surgically implanted a device deep inside her brain, then carefully calibrated the device’s electrical activity to stimulate the networks the had subdued. The results of the clinical trial were published Dec. 4 in Nature Medicine.

The Strange Order of Things by Antonio Damasio review — why feelings are the unstoppable force

The Strange Order of Things by Antonio Damasio review – why feelings are the unstoppable force.

Nietzsche would have given four cheers for this intricately argued book, which is at once scientifically rigorous and humanely accommodating, and, so far as this reviewer can judge, revolutionary. Antonio Damasio, a professor of neuroscience, psychology and philosophy, sets out to investigate “why and how we emote, feel, use feelings to construct our selves … and how brains interact with the body to support such functions”. We are not floating seraphim, he reminds us, but bodies that think – and all the better for it.

From Plato onwards, western philosophy has favoured mind over “mere” body, so that by the time we get to Descartes, the human has become hardly more than a brain stuck atop a stick, like a child’s hobbyhorse. This is the conception of humanness that Damasio wishes to dismantle. For him, as for Nietzsche, what the body feels is every bit as significant as what the mind thinks, and further, both functions are inextricably intertwined. Indeed, from the very start, among the earliest primitive life forms, affect – “the world of emotions and feelings” – was the force that drove unstoppably towards the flowering of human consciousness and the creation of cultures, Damasio insists.

Lost Brain Function Restored in Mice after Stroke

Researchers have succeeded in restoring lost brain function in mouse models of stroke using small molecules that in the future could potentially be developed into a stroke recovery therapy. “Communication between nerve cells in large parts of the brain changes after a stroke and we show that it can be partially restored with the treatment,” says Tadeusz Wieloch, senior professor of neurobiology at Lund University in Sweden.

“Concomitantly, the rodents regain lost somatosensory functions, something that around 60 per cent of all stroke patients experience today. The most remarkable result is that the treatment began several days after a stroke,” Wieloch continues.

In an ischemic stroke, lack of blood flow to the brain causes damage, which rapidly leads to nerve cell loss that affects large parts of the vast network of nerve cells in the brain.