Editor's Note: Don't read the text below until you watch the video above and take the "selective attention" test -- it's harder than you think!
Watching a movie. Listening to a debate. Eavesdropping. Whatever the situation, when we pay close attention to spoken words, we can become "deaf" to other sounds--even ones that come from a guy in a goofy gorilla suit, new research suggests.
Psychologists have long known that selective attention (concentrating closely on one particular thing) affects the way you perceive the surrounding world.
This was demonstrated in dramatic fashion in the celebrated "invisible gorilla" experiment. For the research, psychologists Dr. Daniel Simons and Dr. Christopher Chabris asked study participants to watch a fast-paced video in which a group of people pass a basketball and to count how many times certain people tossed the ball. Actually, you try it (watch the video above).
Did you notice the gorilla in the room? In the middle of the video, a person in a gorilla suit walks into the frame--a seemingly obvious intrusion that was noticed by only about half of the participants in Dr. Simons' study. It wasn't that the participants weren't paying attention but their selective attention had caused inattentional blindness.
Now a new study shows that this same phenomenon occurs with hearing. For her "silent gorilla" study, psychologist Dr. Polly Dalton of the Royal Holloway-University of London asked study participants to listen to two recorded conversations--one between two men and another between two women. In the midst of the conversations, a male voice repeated the phrase "I'm a gorilla" for 19 seconds (you can listen to a demo on Dr. Dalton's website).
The "gorilla man" didn't go completely unnoticed. About 90 percent of study participants said they heard it when listening to the men’s conversation--but only 30 percent noticed the intrusive voice when listening to the women’s conversation, Dr. Dalton told The Huffington Post in an email.
"This is nothing to do with women’s conversations being inherently different from men’s," Dr. Dalton said. "In fact, the men and women were all talking about preparing for a party, so there was no difference in the subject matter. Instead, we think that people noticed the gorilla when attending to the men’s conversation because the gorilla himself was male, so he was relevant to the task that those participants were carrying out."
The bottom line, Dr. Dalton said, is that even seemingly obvious distractions can be missed when attention is focused elsewhere--and that this is true whether the distraction is visual or aural in nature.
"The most interesting finding from this research is just how strong these effects of attention can be," she said. "Most of our participants found it hard to believe that they could have missed such a surprising and distinctive sound."
Dr. Dalton's study, conducted with research associate Nick Fraenkel, is slated for publication in the journal Cognition.
First American Woman In Space
On June 18, 1983, Sally Ride became the first American woman in space. The California-born physicist, then 32, was also the youngest American astronaut at the time. Ride went into orbit aboard the Space Shuttle Challenger.
French scientists announced the isolation of the element boron (atomic number 5) on June 21, 1808. Louis-Joseph Gay-Lussac and Louis-Jacques Thenard reported their discovery just nine days before an English chemist announced similar research.
UFO Crash Dismissed
On June 24, 1997, the U.S. Air Force released a report officially dismissing claims that a UFO had crashed in Roswell, New Mexico in 1947. The document, "The Roswell Report, Case Closed," denied any evidence of an alien landing at the site, claiming the widely reported "crash" was actually nothing more than a government program that was testing parachutes.
Moon Of Pluto Discovered
Charon, the largest moon of the dwarf planet Pluto, was discovered on June 22, 1978 by astronomer James Christy. Charon, which is covered in ice and has no atmosphere, was named after Christy's wife, Charlene.
Alaskan Pipeline Goes On Line
On June 20, 1977, the 800-mile trans-Alaska oil pipeline began delivering oil from Alaska's North Slope. Though criticized for its impact on a delicate ecosystem, the pipeline is considered an epic feat of engineering.
Landmark Creationism Ruling
The U.S. Supreme Court overturned the Louisiana "Creationism Act" on June 19, 1987. The law had prevented the teaching of evolution in public schools unless teachers also taught biblical creationism. Justice William J. Brennan (pictured here) led the 7-2 decision, now considered a major stride for science education in public schools.
The first manned private spaceflight occurred on June 21, 2004, when Mike Melvill piloted SpaceShipOne to an altitude of 62 miles. Built by Burt Rutan and Paul Allen, the one-of-a-kind craft garnered the $10-million Ansari X Prize.
On June 22, 1633, Italian physicist and astronomer Galileo Galilei (1564-1642) was forced to repudiate his heliocentric theory of the solar system, which says that the Earth orbits the sun. First proposed by Copernicus, the theory was considered heresy by church authorities in Rome.
Darwin's Tortoise Dies
On June 23, 2006, a tortoise believed to have been captured by Charles Darwin in the Galapagos Islands died of of heart failure at an Australian zoo. The celebrated reptile--whose age at death was estimated to be 175 years--was considered a national treasure, and was cared for by famous "Crocodile Hunter" Steve Irwin.
Way Before The MacBook...
On June 23, 1868, American inventor Christopher Latham Sholes received a patent for his "Type-Writer" machine. The machine described in the patent helped spark a revolution in communications. Sholes is also credited with the QWERTY keyboard layout.
River On Fire
The Cuyahoga River caught on fire in Cleveland on June 22, 1969. The river, which had been used as a dumping ground for local industrial plants in the area, was likely sparked by a passing train. Outrage over the fire helped fuel the nascent environmental movement.