A brain chemical may help explain why hard thinking leaves us less willing to keep going
In a small experiment, 31 healthy adults took a demanding 20-minute memory test on two separate days, once with real electrical stimulation meant to raise activity in part of the frontal brain and once with a sham version. Boosting that activity improved memory performance at first, but it also raised levels of the brain chemical glutamate and left volunteers less inclined to choose harder, better-paid follow-up tasks. The result points to a possible biological mechanism behind mental fatigue, but with only 31 participants it does not prove this is what drives everyday tiredness.
Source: MedicalXpress — https://medicalxpress.com/news/2026-11-chemical-explanation-tough-tasks.html
How often preschoolers blink may track with how flexibly they switch rules
Researchers studied 113 children aged about three to six and a half in Japan, who played a card-sorting game that required switching between sorting by colour and by shape while cameras counted their natural blinks and forehead sensors tracked frontal brain activity. Children who blinked more often per minute tended to switch rules more accurately, and activity in one right-side frontal region tracked both blink rate and switching success. Because the data come from a single time point, the findings show an association, not that blinking causes flexibility.
Source: Dispatch Times (study in Communications Psychology) — https://dispatchtimes.com/surprising-clue-on-preschoolers-cognitive-flexibility/
Seeing a moving object's position may depend on feedback reaching the brain's first visual area
Using a motion illusion that shifts where a flashed bar appears to be, researchers compared patients with damage to the primary visual cortex with patients whose damage lay in the pathway feeding that area, as well as healthy volunteers. Patients with damage to the visual cortex itself could not see the bar when the illusion moved it into their blind field, while those with an intact visual cortex could. The pattern suggests that feedback signals arriving in the first visual area are needed for conscious awareness of a moving object's predicted position, though this is a small study of patients with brain lesions.
Source: MedicalXpress — https://medicalxpress.com/news/2026-11-intact-primary-visual-cortex-conscious.html