The Mystery

What is sleep? It’s when neurotransmitters, the nerve-signaling chemicals in our bodies, stop producing serotonin and norepinephrine, which keeps our brain active and awake. Instead, these neurons switch off. At the same time, a chemical known as adenosine, builds up in our blood, causing drowsiness. There are four different stages of sleep:     Stage 1: Light sleep – the phase between being awake and falling asleep.     Stage 2: The onset of sleep – body temperature drops. You may have experienced ‘hypnic jerks’ where you jump awake, or dream of falling off a curb or out of a plane…quite startling! This is quite normal. It can sometimes happen when our body and mind are winding down at different rates. If you find the frequency of hypnic jerks increasing beyond what is normal for you, working on the quality of your ‘you time’ before bed and making sure you have a consistent sleep pattern can help to reduce them.     Stage 3: Deepest and most restorative sleep takes place. Note: It is

A new artificial intelligence system called a 'Semantic Decoder' can translate a person’s brain activity — while listening to a story or silently imagining telling a story — into a continuous stream of text. The system developed by researchers at The University of Texas at Austin might help people who are mentally conscious yet unable to physically speak, such as those debilitated by strokes, to communicate intelligibly again. The study, published in the journal Nature Neuroscience, was led by Jerry Tang, a doctoral student in computer science, and Alex Huth, an assistant professor of neuroscience and computer science at UT Austin. The work relies in part on a transformer model, similar to the ones that power Open AI’s ChatGPT and Google’s Bard. Unlike other language decoding systems in development, this system does not require subjects to have surgical implants, making the process noninvasive. Participants also do not need to use only words from a prescribed list. Brain activi

If dreams are the royal road to the unconscious, as Freud claimed, then that route may be a highway full of tortuous twists and turns—leading nowhere. But it affords some spectacular vistas along the way. By turns, dreams have been deemed prophecies of the future, full of meaning—if only someone could figure out what it is—or the effluence of nerve cells randomly unwinding from a busy day. Once considered a hallmark of the periodic surges of brain activity known as rapid-eye-movement sleep, dreaming now seems somewhat less bundled up; at least 25 percent of dreams are scattered through other parts of the night. Dreaming has been seen as critical for learning, or at least important for solving problems—or as nice but unnecessary. It's an emblem of mental illness—or a safety shield deflecting it. The newest switchback on dreams comes from South African neuroscientist Mark Solms. Maybe, says Solms, we've been confusing cause and effect. Dreams, he suggests, are not a by-product of

The paradigmatic assumption that REM sleep is the physiological equivalent of dreaming is in need of fundamental revision. A mounting body of evidence suggests that dreaming and REM sleep are dissociable states, and that dreaming is controlled by forebrain mechanisms. Recent neuropsychological, radiological, and pharmacological findings suggest that the cholinergic brain stem mechanisms that control the REM state can only generate the psychological phenomena of dreaming through the mediation of a second, probably dopaminergic, forebrain mechanism. The latter mechanism (and thus dreaming itself) can also be activated by a variety of nonREM triggers. Dreaming can be manipulated by dopamine agonists and antagonists with no concomitant change in REM frequency, duration, and density. Dreaming can also be induced by focal forebrain stimulation and by complex partial (forebrain) seizures during nonREM sleep, when the involvement of brainstem REM mechanisms is precluded. Likewise, dreaming is