Much like the origins of Valentine’s Day, the real identity of St. Valentine remains a bit of a mystery. The holiday’s namesake, a martyred priest, actually could have been one of multiple men. Although many think of him as the patron saint of lovers, this reputation likely began centuries after his death.

For decades, diagnosing Alzheimer’s disease (AD) has required access to specialist memory clinics, neuroimaging or invasive cerebrospinal fluid (CSF) testing. That paradigm is starting to shift. In 2025, the US Food and Drug Administration (FDA) cleared the first blood-based biomarker tests intended to aid the assessment of AD.

For more than a century, psychologists thought that the infant experience was, as the psychologist and philosopher William James famously put it, a “blooming, buzzing confusion.” But new research suggests babies are born with a surprisingly sophisticated neurological toolkit that can organize the visual world into categories and pick out the beat in a song.