Attention and Perception

Our ability to make sense of the world depends not only on what we sense but also on what we notice.

Attention plays a major role in determining which information we consciously perceive and which fades into the background.

The Power of Attention

Imagine you’re at a crowded party filled with music, chatter, and laughter.

Even though your sensory receptors are taking in every sound, you’re likely tuned in to just one conversation. If someone asked what song had just finished playing, you might not know—you never consciously perceived it.

This ability to focus on certain stimuli while ignoring others allows us to function in a noisy, complex world—but it also means we can miss things that are right in front of us.

See for yourself how inattentional blindness works by watching this selective attention test from Simons and Chabris (1999):

You can view the transcript for “selective attention test” here (opens in new window).

When Focus Blinds Us: Inattentional Blindness

One of the most striking demonstrations of attention’s limits comes from a famous experiment shown above by Daniel Simons and Christopher Chabris (1999).

Participants watched a short video of two teams—one wearing white shirts and the other black—passing basketballs. They were instructed to count how many times the white team passed the ball.

Halfway through the video, a person in a black gorilla costume walked through the players, paused, and even beat their chest before exiting the frame. The gorilla was visible for a full nine seconds—yet about half of the viewers never noticed it.

inattentional blindness

Inattentional blindness is the failure to notice something that is completely visible because the person was actively attending to something else and did not pay attention to other things (Mack & Rock, 1998; Simons & Chabris, 1999).

In a similar study, Most et al. (2000) asked participants to watch images move across a computer screen and focus only on either white or black objects.

When a red cross appeared and drifted across the screen, about one-third of the participants didn’t see it at all. Their attention was so narrowly focused that the new, unexpected object never entered conscious awareness.

Everyday Example

Inattentional blindness isn’t limited to lab settings.

It’s why a driver might fail to notice a pedestrian while focusing on traffic lights, or why you might miss a friend waving at you while scrolling on your phone.

Our brains constantly filter sensory input to avoid overload—but this selectivity can come at the cost of awareness.

Research Spotlight: Multitasking, Attention, and What to Do Instead

Trying to “do it all” at once slows you down and makes learning stick less. Task-switching creates measurable time and accuracy costs because the brain must reconfigure on each switch.

In class and while studying, device multitasking—like hopping between notes, texts, and tabs—reduces recall for you and nearby peers (Sana, Weston, & Cepeda, 2013) and is linked, on average, to weaker attentional control across large samples (Chen et al., 2025).^[1]

Research also shows heavy media multitaskers struggle more with filtering distractions and switching efficiently (Ophir, Nass, & Wagner, 2009), and phone use during lectures lowers test performance (Kuznekoff & Titsworth, 2013).         

Try this:

• Single-task in short sprints. Work in 20–30-minute focus blocks, then take a quick break to reset attention. 
• Phone out of sight; notifications off. Reducing alerts during learning improves retention (Kuznekoff & Titsworth, 2013). 
• Batch your switching. Check messages only between blocks; frequent toggling compounds switch costs (Sana et al., 2013). 
• Go full-screen or use blockers. Fewer on-screen temptations = fewer costly attention shifts (Chen et al., 2025).^[2]

 

 

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