When a scene changes, it is difficult to detect the differences. When a cue is present it is easier to spot change

University of Michigan - Ann Arbor

Inattentional blindness is a psychological phenomenon where an individual fails to perceive a fully visible, yet unexpected, stimulus because their attention is engaged on a different task or object. This occurs because attentional resources are limited, and focusing on a primary task can effectively prevent other prominent stimuli in the visual field from being consciously processed.

Inattentional Blindness

Goldstein, E. B. (2014). Cognitive psychology: Connecting mind, research and everyday experience. Nelson Education.


Cognitive psychology: Connecting mind, research and everyday experience

Change blindness

People tend to pay attention to the weapon while a crime is being committed (a highly emotional situation). This can restrict a witness' awarenesses of the events leading up to and during a crime.

Weapons focus

CBP creates dissociations between action and outcome. For example, a CBP study showed faces to participants and asked them to choose the more attractive face, the participants were then shown the results of their choices but the faces they picked got slightly manipulated. The participants often did not notice the manipulation and blindly agreed with what they thought was their previous choice. 

Choice Blindness Paradigm (CBP)

A famous study by Daniel Simons and Christopher Chabris (1999) provides a powerful demonstration of inattentional blindness. In the experiment, participants were instructed to count the number of basketball passes made by a team in white shirts. While they were focused on this task, a person in a gorilla costume walked through the scene for nine seconds. Remarkably, nearly half of the participants failed to notice the gorilla, illustrating how intense focus on one activity can make people completely miss other, otherwise obvious, visual stimuli.

Example of Inattentional Blindness: The Invisible Gorilla Test (Simons & Chabris, 1999)

In an experiment by Most et al. (2000), participants' inattentional blindness was tested by having them observe a computer screen with numerous black and white shapes moving across it. They were instructed to focus on the shapes of one color while ignoring the other. During this task, a red cross passed across the screen. Despite its clear visibility, about one-third of the participants failed to notice the red cross, demonstrating how intense focus on a specific activity can prevent the perception of other unexpected stimuli.

Learn Before

Related