The limits of attention
It wasn't part of the plan when I decided to become a neuroscientist, let alone a writer (much less a columnist for Folha!)—and even less so to become the host of a television series (about neuroscience, of course). But here I am, loving my duties as a “neuroscientist on call” – and, as a bonus, learning unusual things about the neuroscience of everyday life.
For example: how many people does it take to record two minutes of video? “About three” was my naive guess, based on the teams that occasionally come to the lab to record interviews. To my amazement, during a break in front of the cameras in the studio, I noticed that there was a team of no less than... thirty people with their eyes glued to me. Why so many people to take care of just one person and one scenographic brain on video?
My neuroscientist-on-call side took advantage of the waiting time under the spotlights (deliciously warm in the cold studio) to think about it: this can only be due to our limited attention span.
Paying attention means selectively allocating our cognitive resources to a single focus, which makes processing faster and more accurate, to the detriment of others, which become less detectable or salient. In practice, this works as a filter that highlights everything related to a piece of information—but at the expense of all the others, which “disappear” in the background.
The good news is that we are always paying attention to something: even the “distracted” brain is actually attentive to internal mental processes (the day's schedule, the evening meeting, yesterday's movie) or busy following the distraction of the moment (such as a fly or a pretty girl walking by).
The bad news is that we can only consciously do one thing at a time—like taking care of the lighting, the sound, the wrong shadows, the cables, the camera, the stray hairs, the makeup, the lines, the sequence, each function of the cortex of a different person so that everything comes out right at the same time. Or take care of the whole, which is the job of the director's cortex—who, in order to get the whole thing right, can't pay attention to the parts.
Considering that it's just me and a brain on stage, there are “only” thirty people on set. Imagine how many brains focused on one thing at a time must be needed to shoot a scene for a soap opera or movie, with dozens of actors and extras, complicated sets, and things moving around...
Excerpt from Suzana Herculano-Houzel (2025) Neurociência da Vida Comum (Neuroscience of Everyday Life), originally published in Folha de São Paulo in November 2008