🧠💊📊

Researchers from the University of Bonn delve into the complex relationship between ketamine and social cognition deficits in schizophrenia, revealing both promising and cautionary insights.

For more than a century, researchers have known that people are generally very good at eyeballing quantities of four or fewer items. But performance at sizing up numbers drops markedly — becoming slower and more prone to error — in the face of larger numbers.

Now scientists have discovered why: the human brain uses one mechanism to assess four or fewer items and a different one for when there are five or more. The findings, obtained by recording the neuron activity of 17 human participants, settle a long-standing debate on how the brain estimates how many objects a person sees. The results were published in Nature Human Behaviour on 2 October.

The finding is relevant to the understanding of the nature of thinking, says psychologist Lisa Feigenson, the co-director of the Johns Hopkins University Laboratory for Child Development in Baltimore, Maryland. “Fundamentally, the question is one of mental architecture: what are the building blocks that give rise to human thought?”

The Blue Brain Project introduces a universal workflow for creating and validating neuronal models using open-source tools.

Biophysically detailed neuronal models provide a unique window into the workings of individual neurons. They enable researchers to manipulate neuronal properties systematically and reversibly, something that is often impossible in real-world experiments.

These in silico models have played a pivotal role in advancing our understanding of how neuronal morphology influences excitability and how specific ion currents contribute to cell function. Additionally, they have been instrumental in building neuronal circuits to simulate and study brain activity, offering a glimpse into the complex dance of neurons that underlies our thoughts and actions.

Specific patterns of electrical activity in the hippocampus may indicate whether someone is about to misremember an event.

Whether improperly closing a door or shanking a kick in soccer, our brains tell us when we’ve made a mistake because these sounds differ from what we expect to hear. While it’s long been established that our neurons spot these errors, it has been unclear whether there are brain cells that have only one job—to signal when a sound is unexpected or “off.”

A team of New York University neuroscientists has now identified a class of neurons—what it calls “prediction-error neurons”—that are not responsive to sounds in general, but only respond when sounds violate expectations, thereby sending a message that a mistake has been made.

“Brains are remarkable at detecting what’s happening in the world, but they are even better at telling you whether what happened was expected or not,” explains David Schneider, an assistant professor in NYU’s Center for Neural Science and the senior author of the study, which appears in JNeurosci. “We found that there are specific neurons in the brain that don’t tell you what happened, but instead tell you what went wrong.”