Brain Scientists Explore the How of When

“These cells are encoding information related to time, and this information is clearly important for memory,” Dr. Lega said.

In effect, Dr. Lega said, the cells representing time fired to support an activity, in this case to track the passage of the 30-second interval. There is no constant rhythm or background beat; the time signal is conjured as needed. “There’s no internal metronome, or clock,” he said. The time cells are “firing to support what you’re doing.”

That is, time cells adjust to the demands being made on the brain, in real time, moment to moment. Another group of nearby neurons, called ramping cells, accelerates its firing as a task begins and decelerates or decays as the job winds down, marking off chunks of time. “As these cells are sensitive to contextual changes during experience, they could represent the slowly evolving nature of contextual information,” the authors write.

The coordinated activity of time cells and ramping cells, on its own, is far too basic to encompass the weirdness of pandemic time. This mechanism counts out time in seconds and minutes, not days and weeks. Our perception of those longer intervals seems to be shaped much more by the quantity and content of the memories that fill them, and by the emotions that help imprint them.

Starting in March, people had to absorb an enormous amount of news and information about the virus, the symptoms and various interventions, on top of work and child demands. But with stay-at-home orders, the context flattened. Each day looked a whole lot like the last, and the next, and the next. Like being lost at sea, we have floated in place while the earth turned underfoot.

Pandemic time, the subjective kind, will likely feel warped for a while — until we make landfall, however that comes to pass.

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