AE Files

PERCEPTIONVOLUME 28, 1999Gorillasin Our MidstDANIEL J. SIMONSCHRISTOPHER F. CHABRISHARVARD UNIVERSITY
Named:
1992, Arien Mack and Irvin Rock
Key study:
1999, Daniel Simons and Christopher Chabris, Harvard University
Published:
Perception, vol. 28

Inattentional blindness is the failure to see a visible object because attention is on something else. The eyes work and the object crosses the center of the visual field. It goes unregistered. In 1999, half of the people counting basketball passes in a video missed a person in a gorilla suit who walked into the game, faced the camera and thumped its chest.

The result contradicts the idea that vision records a scene the way a camera does. Seeing requires attention, and attention goes to the task. Confidence does not track the gap. Most people are certain they would notice the gorilla. The same mechanism hides the motorcycle at a junction and the warning at the top of a screen.

FIG. 1 SELECTIVE LOOKING TASKWWWBBBUNEXPECTED FIGURECOUNT THE PASSES IN WHITE9 S ON SCREEN

The Gorilla (1999)

Observers count passes between the players in white. A person in a gorilla suit walks through the game and stays on screen for nine seconds. Half of the observers report nothing unusual.

The Radiologists (2013)

Twenty-four radiologists search lung scans for nodules. The last scan contains a gorilla 48 times the size of a nodule. Twenty of them miss it. Eye tracking shows that most of the twenty looked straight at it.

FIG. 2 EYE TRACK, FINAL SCANINSERTED FIGURE48 × NODULE SIZE24 RADIOLOGISTS20 REPORT NOTHING
FIG. 3 JUNCTION, TOP VIEWMOTORCYCLE, IN VIEWDRIVERLOOKING FOR CARSLOOKS LEFT. REGISTERS NOTHING. PULLS OUT.

Looked but Failed to See

A crash category in road safety research. The driver checks the junction, registers no vehicle and pulls out into a motorcycle that was in plain view. One account is that the driver was searching for cars.

Attention Residue

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