But when you actually pay attention to something you’re listening to, whether it is your favorite song or the cat meowing at dinnertime, a separate “top-down” pathway comes into play. Here, the signals are conveyed through a dorsal pathway in your cortex, part of the brain that does more computation, which lets you actively focus on what you’re hearing and tune out sights and sounds that aren’t as immediately important.
In this case, your brain works like a set of noise-suppressing headphones, with the bottom-up pathways acting as a switch to interrupt if something more urgent — say, an airplane engine dropping through your bathroom ceiling — grabs your attention.
Hearing, in short, is easy. You and every other vertebrate that hasn’t suffered some genetic, developmental or environmental accident have been doing it for hundreds of millions of years. It’s your life line, your alarm system, your way to escape danger and pass on your genes. But listening, really listening, is hard when potential distractions are leaping into your ears every fifty-thousandth of a second — and pathways in your brain are just waiting to interrupt your focus to warn you of any potential dangers.
Listening is a skill that we’re in danger of losing in a world of digital distraction and information overload.
In a famous psychology experiment, participants watching a video of people passing a basketball around while moving missed a remarkable sight: Midway through the video, someone wearing a gorilla suit strolls through the exercise, pauses to beat his chest, and moves on. Participants were asked with a cognitive task: counting the number of passes made by players wearing white shirts, and the focus on one activity induced a kind of blindness to the extraordinary visitor.
A new study shows that inattentional deafness exists, too. Forty-five people listened to a 3D, stereo recording, lasting just over a minute, of two men and two women independently discussing preparations for a party. Half the participants were instructed to listen closely to the men’s conversation, half to the women’s. Halfway through the recording, a man moves through the audio landscape saying “I’m a gorilla. I’m a gorilla,” before exiting. This lasts 19 seconds.
Afterward, when asked if they heard anything odd, 90% of the participants who were attending to the male voices mentioned the gorilla-man — but only 30% of the participants focusing on the female voices did.
All but one of 45 people in a control group—they were asked simply to listen to the tape—mentioned the gorilla interloper immediately.
As it happens, the path the gorilla took, in this experiment, took him closer to the men than to the women—so spatial proximity to the male voices played some role. To test how great that role was, the researchers did a second experiment in which the male gorilla-voice appeared nearer to those of the women. That reduced the effect but hardly eliminated it: 55% of listeners told to pay close attention to the female speakers failed to notice the person saying, “I’m a gorilla.”
Very interesting how we can be dismissive of visual and auditory cues when we shift our attention.
(via Wall Street Journal)