July 30, 2025 – A human brain doesn’t pay attention in one smooth stream—instead, it behaves more like a strobe light: flickering at a steady rhythm, according to new research by the Hebrew University of Jerusalem (HU). 

Prof. Ayelet N. Landau from HU’s Psychology Department and the Department of Cognitive and Brain Sciences proposes a bold reframing of how attention functions. In a new opinion piece published in Trends in Cognitive Sciences, Prof. Landau and her team—Daniele Re and Flor Kusnir—suggest that our brains process the visual world in rapid snapshots roughly eight times per second. In their theory, called “attentional sampling,” when forced to split attention between two objects, that rate drops to four snapshots per second for each. 

This process helps the brain cope with too much information by jumping back and forth between different visual stimuli, like the brain is taking rapid snapshots instead of watching a constant video. It helps explain how we make sense of a busy world, even when we don’t notice it happening.  

According to the researchers, this rhythmic alternation between the objects or features that capture our attention helps resolve the competition for neural processing that emerges among them. This isn’t just a quirk of perception. The researchers argue it’s a fundamental solution to a deep problem for cognition and its neural implementation: competition. 

“Our environment bombards us with visual information, but our brain can’t process everything at once,” Prof. Landau explains. “What we’re seeing in attentional sampling is the brain’s way of resolving this—by rhythmically switching between competing inputs.” 

The phenomenon builds on a well-established theory known as “biased competition,” which holds that different neural populations in the brain’s visual system fight for dominance when multiple stimuli are present. Traditionally, scientists thought attention simply ‘boosted’ one signal over another. But Landau’s team suggests that, under certain conditions, the brain doesn’t pick a side—instead, it takes turns. 

The researchers examined studies ranging from early visual processing in the eye channels to high-level object recognition. Even when people weren’t aware of the visual conflict—such as when two images are subtly shown to different eyes—this sampling rhythm emerged, revealing a covert, automatic mechanism for selection. 

This rhythm persists even when attention isn’t consciously engaged, hinting at a default oscillatory mode of perception. “These aren’t conscious shifts,” said Prof. Landau. “Even when we think we’re focusing on a single object, our attention may be dancing across the scene in ways we don’t realize.” 

So, what is controlling this rhythm? That remains a matter of scientific debate. Some evidence suggests that higher-level brain regions—like those involved in decision-making—may act like a conductor, coordinating this mental beat. Others point to local circuits in the visual cortex itself. Either way, the implications stretch beyond vision. Understanding how the brain resolves competition could influence everything from interface design to neurological therapies. 

Landau’s lab has been central in uncovering these hidden rhythms for over a decade. “What excites me,” she said, “is that this could be a general principle—not just for visual attention, but for how the brain manages overload across all sensory systems.” 

The research paper titled “Attentional Sampling Resolves Competition along the Visual Hierarchy” is now available in Trends in Cognitive Sciences and can be accessed here.

Researchers: 

Daniele Re1,2, Flor Kusnir1 and Ayelet N. Landau1,3,4 

Institutions: 

  1. The Psychology Department and the Department of Cognitive and Brain Sciences, The Hebrew University of Jerusalem 
  2. Center for Nanoscience and Nanotechnology, Tel Aviv University 
  3. Experimental Psychology, University College London (UCL) 
  4. Einstein Center Chronoi, Berlin