This shows a brain.
The findings also might also have evolutionary implications. Credit: Neurosciene News

Revisiting the Invisible Gorilla: Fast-Moving Unexpected Objects Capture Attention

Summary: A study challenges the long-held belief that our ability to spot unexpected objects is compromised when focused on a separate task. The team showed that individuals are surprisingly good at noticing fast-moving objects entering their field of vision, even when concentrating elsewhere.

This research, exploring the phenomenon of ‘inattentional blindness’, suggests that we are less capable of spotting slowly moving unexpected objects. The findings may carry evolutionary implications, hinting at a ‘sentinel’ system that alerts us to potential fast-moving threats.

Key Facts:

  1. Researchers demonstrated that people can notice unexpected fast-moving objects, challenging the widely accepted concept of inattentional blindness.
  2. Participants were less likely to notice slowly moving unexpected objects, confirming aspects of the original inattentional blindness theory.
  3. The findings suggest the existence of a ‘sentinel’ system, which might have evolved to alert us to potential fast-moving threats.

Source: NYU

We are quite good at spotting unexpected objects while focused on another activity if they are moving fast, reveals a new study by a team of New York University researchers. Their findings cast doubt on a long-standing view that our ability to see the unexpected is necessarily impaired when our attention is already directed elsewhere.

“For decades, it’s been thought that when we’re intently focused on something relevant, like driving or playing a game, we fail to spot something that unexpectedly enters our field of vision, even if it is clearly visible and moving,” says Pascal Wallisch, a clinical associate professor at New York University’s Center for Data Science and Department of Psychology and lead author of the paper, which appears in the Proceedings of the National Academy of Sciences.

“Our study questions the generality of this view because it shows that people, while focusing on a task, are quite capable of noticing unexpected objects that are moving quickly. However, our research confirms that we are indeed less adept at noticing these same objects when they are moving slowly.”

The research team, who also included Wayne Mackey, Michael Karlovich, and David Heeger, centered its study on “inattentional blindness”—the inability to notice unexpected objects if attention is focused on a task.

This phenomenon was evident in the widely cited 1990s “invisible gorilla experiment.” In that study, the participants—watching a video of students passing basketballs—did not notice an unexpectedly appearing person in a gorilla costume because they were already tasked with, and engaged in, counting the number of passes between players wearing white shirts. 

This and similar studies characterized one of the most striking phenomena in cognitive psychology—inattentional blindness—as an inevitable flip side of task focusing, and essentially a deficit. 

In the PNAS study, the NYU research team sought to better understand the nature of inattentional blindness through a series of experiments—and, specifically, whether our cognitive processing was indeed as limited as this previous work suggested. 

They replicated the invisible gorilla experiment using more than 1,500 of research participants—but including several new conditions. In the original 1999 experiment, the gorilla moved slowly as well as upright—like a human (which it was!). 

In the new PNAS research, research participants saw the gorilla (yes, also a human dressed in a gorilla costume) in additional ways.

Specifically, the “NYU gorilla” moved at various speeds—in some conditions, just a little faster than the “original gorilla” and, in others, substantially faster than the original gorilla.

During these experiments—just like in the original experiment—research participants were tasked with counting the number of basketball passes made by players wearing black or white shirts.

Credit: Lascap Foxman

Overall, the results showed that participants, while engaged in the pass-counting task, were more likely to spot the NYU gorilla if it was moving substantially faster than in the original 1999 experiment or if it was leaping instead of walking. 

To ensure these findings generalize beyond spotting gorillas, the researchers then conducted a series of experiments, using approximately 3,000 other participants, that replicated the principles of the invisible gorilla study.

In these, research participants were asked to count how many randomly moving dots of a given color were crossing a central line while an unexpected moving object (UMO) —a triangle— was traversing the screen at various speeds.

As with the gorilla study, the participants were more likely to spot the triangle the faster it was moving. Importantly, the authors note, the same was not observed for triangles that were moving slower than the dots, which is remarkable given that the slower moving triangles are on the screen substantially longer.

This finding also rules out the following: that the noticeability of the fast moving UMOs is simply due to physical dissimilarity to the task-relevant dots. As the authors write in the paper:  

“(O)ur findings…contribute to the ongoing debate on the impact of physical salience on inattentional blindness, suggesting that it is fast speeds specifically, not the physical salience of a feature more generally, that captures attention.”

The findings also might also have evolutionary implications. The classical view of inattentional blindness would leave a task-focused organism vulnerable to unexpected threats.

These new PNAS findings, by contrast, suggest that organisms possess a “sentinel” system that constantly monitors the environment. This system alerts organisms to potential threats—specifically, fast-moving attacking predators. 

“Fast-moving, unexpected objects seem to override the task focus of an organism,” says Wallisch. “This will allow it to notice and react to the new potential threat, improving chances of survival.” 

Funding: The research was supported by a grant from the National Science Foundation (DGE 1342536).

About this neuroscience research news

Author: James Devitt
Source: NYU
Contact: James Devitt – NYU
Image: The image is credited to Neuroscience News

Original Research: Closed access.
The Visible Gorilla: Unexpected fast – but not physically salient – objects are noticeable” by Pascal Wallisch et al. PNAS


The Visible Gorilla: Unexpected fast – but not physically salient – objects are noticeable

It is widely believed that observers can fail to notice clearly visible unattended objects, even if they are moving.

Here, we created parametric tasks to test this belief and report the results of three high-powered experiments (total n = 4,493) indicating that this effect is strongly modulated by the speed of the unattended object. Specifically, fast—but not slow—objects are readily noticeable, whether they are attended or not.

These results suggest that fast motion serves as a potent exogenous cue that overrides task-focused attention, showing that fast speeds, not long exposure duration or physical salience, strongly diminish inattentional blindness effects.

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