Summary: Why humans and animals need sleep remains one of biology’s enduring mysteries. A prominent explanation, the synaptic homeostasis hypothesis, proposes that synaptic connections strengthen and accumulate during wakefulness as we learn and process information. This continuous growth increases energy demand and protein accumulation in the brain, so sleep functions as a systemic reset that … Read more

Summary: New research overturns the long-held idea that our ancestors gradually grew larger in a steady progression. An analysis of 386 fossil specimens from 21 hominin species supports a dual-mechanism model: slow, incremental size increases among early hominins such as Australopithecus, followed by a rapid, non-linear increase in body mass around 2–2.5 million years ago. … Read more

Summary: Watching a film often feels effortless: we follow speech, read facial expressions, notice musical cues, and piece together quick scene changes into a coherent story. Underneath this smooth experience, the brain constantly and rapidly decides which sensory input—sound or sight—should take priority at each moment. A recent study shows the frontal cortex functions like … Read more

Summary: New research links accelerated biological aging with the rising incidence of early-onset cancers—those diagnosed at age 55 or younger—across recent generations. By analyzing biomedical and molecular data from more than 154,000 UK Biobank participants and over 10,000 people in the U.S. All of Us Research Program, investigators measured the gap between chronological age and … Read more

Summary: A large brain-imaging study led by researchers at the University of Kansas examined how lifetime exposure to reproductive hormones relates to brain structure in older women. The results reveal that greater cumulative exposure to estrogen — from early-life hormonal birth control, midlife menopausal hormone therapy (MHT), or a naturally later menopause — is linked … Read more

Summary: A new longitudinal study shows that when children are exposed to screens can be as important for long-term cognitive development as how much time they spend in front of screens. Neuroscientists and pediatric researchers followed 502 children for nearly a decade, recording parent-reported screen use at six time points from age 1 through age … Read more

Summary: Laughter is one of humanity’s most universal social signals, yet researchers have struggled to map the precise brain circuits that produce it because genuine, unforced mirth is hard to generate in laboratory settings. An international team overcame this challenge by reviewing clinical reports from awake pre-surgical epilepsy patients. During these procedures, focused electrical stimulation … Read more

Summary: Researchers have identified an evolutionarily ancient circuit in the brainstem that functions as a core “attentional selection engine.” Long-held views placed selective spatial attention primarily in the prefrontal cortex, a region prominent in primates and humans. That model did not explain how birds, fish, and reptiles successfully filter distractions. New experiments in mice reveal … Read more

Summary: A new study overturns a long-standing assumption in human evolution: body size did not increase steadily and uniformly across our ancestors. Analysis of 386 fossil specimens representing 21 hominin species supports a dual-mechanism model. Early hominins such as Australopithecus show a modest, gradual increase in mass, while a large, non-linear evolutionary jump occurred between … Read more

Summary: Researchers have identified a naturally occurring lipid, erucamide, as a key coordinator of the retina’s protective response to injury. The study shows that endogenous erucamide levels fall sharply as light‑sensing photoreceptors degenerate, and that restoring erucamide preserves the retinal neurovascular unit. Rather than acting directly on photoreceptors, erucamide binds to the TMEM19 protein on … Read more