Reference Terms
from Wikipedia, the free encyclopedia
Left-handed
A person who is left-handed primarily uses his or her left hand, more so than the right hand; a left-hander will probably use the left hand for tasks such as personal care, cooking, and so on. Writing is not as precise an indicator of handedness as it might seem, because many left-handed people write with their right hand but use their left hand for other tasks. Approximately 8 to 15% of the adult population is left-handed. Studies indicate that left-handedness is more common in males than females. Left-handedness, in comparison to the general population, also appears to occur more frequently in identical twins, and several groups of neurologically disordered individuals (people suffering from epilepsy, Down's Syndrome, autism, mental retardation, dyslexia, etc.)There have been many famous left-handed people, and the associated right brain hemisphere that is said to be more active in left-handed people has been found in some circumstances to be associated with genius and is correlated with artistic and visual skill.
Related Stories
1
2
Mind & Brain News
February 27, 2026
Feb. 26, 2026 Worrying about getting older—especially fearing future health problems—may actually speed up aging at the cellular level, according to new research from NYU. In a study of more than 700 women, those who felt more anxious about aging showed signs ...
Feb. 25, 2026 Scientists have zeroed in on a critical weak spot behind a rare but devastating brain autoimmune disorder often known as “Brain on Fire.” The disease strikes when the immune system attacks NMDA receptors—key molecules involved in memory and ...
Feb. 25, 2026 A weeklong, high-intensity version of TMS may work nearly as well as the standard six-week treatment for depression. In a UCLA study, patients who received five sessions a day for five days experienced meaningful symptom relief comparable to those ...
Feb. 24, 2026 Subtle changes in brain blood flow and oxygen use are closely linked to hallmark signs of Alzheimer’s, including amyloid plaques and memory-related brain shrinkage. Simple, noninvasive scans may one day help spot risk earlier—by looking at the ...
Feb. 23, 2026 Scientists have created a blood test that can estimate when Alzheimer’s symptoms are likely to begin. By measuring a protein called p-tau217, the model predicts symptom onset within roughly three to four years. The protein mirrors the silent ...
Feb. 21, 2026 A common bacterium best known for causing pneumonia and sinus infections may also play a surprising role in Alzheimer’s disease. Researchers found that Chlamydia pneumoniae can invade the retina and brain, where it sparks inflammation, nerve cell ...
Feb. 20, 2026 Exercise may sharpen the mind by repairing the brain’s protective shield. Researchers found that physical activity prompts the liver to release an enzyme that removes a harmful protein causing the blood-brain barrier to become leaky with age. In ...
Feb. 20, 2026 A groundbreaking clinical trial is testing whether specially engineered stem cells can help the brain restore its own dopamine production in people with Parkinson’s disease. Because the condition is driven by the gradual loss of dopamine-producing ...
Feb. 20, 2026 Breathing polluted air may do more than harm your lungs — it could also increase your risk of Alzheimer’s disease. In a sweeping study of nearly 28 million older Americans, researchers found that ...
Feb. 18, 2026 Sugary drinks may be linked to more than just physical health problems in teens. A new review of multiple studies found a consistent association between high consumption of beverages like soda, energy drinks, sweetened juices, and flavored milks and ...
Feb. 18, 2026 A major new study has spotlighted three familiar medicines that could take on an unexpected new role in the fight against Alzheimer’s disease — with a shingles vaccine emerging as the front-runner. After reviewing 80 existing drugs, an ...
Feb. 17, 2026 Researchers have identified two brain receptors that help the brain clear away amyloid beta, a hallmark of Alzheimer’s disease. By stimulating these receptors in mice, scientists increased levels of a natural amyloid-breaking enzyme, reduced ...
Latest Headlines
updated 12:56 pm ET
Feb. 20, 2026 Human language may seem messy and inefficient compared to the ultra-compact strings of ones and zeros used by computers—but our brains actually prefer it that way. New research reveals that while ...
Feb. 19, 2026 That viral claim that your frontal lobe “isn’t fully developed until 25” turns out to be more myth than milestone. Early brain scans showed that gray matter changes dramatically through the ...
Feb. 16, 2026 A parasite that may already be hiding in your brain has a shocking survival trick: it can infect the very immune cells sent to destroy it. Yet most ...
Feb. 16, 2026 For years, compulsive behaviors have been viewed as bad habits stuck on autopilot. But new research in rats found the opposite: inflammation in a key decision-making brain region actually made ...
Feb. 16, 2026 A sweeping review of global research suggests that exercise—especially aerobic activities like running, swimming, and dancing—can be one of the ...
Feb. 15, 2026 A new Stanford study suggests math struggles may be about more than numbers. Children who had difficulty with math were less likely to adjust their thinking after making mistakes during number ...
Feb. 15, 2026 Scientists have created the most detailed maps yet of how genes control one another inside the brains of people with Alzheimer’s disease. Using a powerful new AI-based system called SIGNET, the ...
Feb. 15, 2026 Sleeping on a problem might be more powerful than we ever imagined. Neuroscientists at Northwestern University have shown that dreams can actually be nudged in specific directions — and those dream ...
Feb. 15, 2026 Psychedelics can quiet the brain’s visual input system, pushing it to replace missing details with vivid fragments from memory. Scientists found that slow, rhythmic brain waves help shift ...
Feb. 14, 2026 Couples who intentionally slow down and soak in their happy moments together may be building a powerful shield for their relationship. Researchers at ...