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Summary: A new study challenges the belief that larger groups reduce cooperation, showing instead that flexible social connections enhance teamwork. Researchers found that in a prisoner’s dilemma game, participants in bigger groups cooperated more frequently, despite memory limitations.

Brain scans revealed that when memories of past interactions were unclear, participants relied on prosocial instincts to guide behavior. Key brain regions, including the prefrontal cortex and nucleus accumbens, helped balance memory, reward, and decision-making.

The default mode network (DMN) is implicated in cognition and behavior. Here, the authors show that the DMN is cytoarchitecturally heterogeneous, it contains regions receptive to input from the sensory cortex and a core relatively insulated from environmental input, and it uniquely balances its output across sensory hierarchies.

The study looked at the effect of cannabis use on young adults who are recent or heavy users

AURORA, Colo., Jan. 28, 2025 /PRNewswire/ — A new study published today in JAMA Network Open explores the effects of both recent and lifetime cannabis use on brain function during cognitive tasks.

The study, the largest of its kind ever to be completed, examined the effects of cannabis use on over 1,000 young adults aged 22 to 36 using brain imaging technology. The researchers found that 63% of heavy lifetime cannabis users exhibited reduced brain activity during a working memory task, while 68% of recent users also demonstrated a similar impact.

What if time didn’t just move forward? Scientists have uncovered something astonishing in a recent quantum physics experiment — the existence of ‘negative time.’ This mind-bending discovery defies conventional logic, suggesting that particles may not follow the rules we thought were unbreakable.

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Jeffrey Shainline is a physicist at NIST working on. Note: Opinions expressed by Jeff do not represent NIST.

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