Ears, eyes & mind can be easily influenced

If you listen to the above video, then begin to focus on each line of text, for several seconds, you can easily convince yourself that they are indeed saying what’s printed on the screen. This, it appears that our ears, can be easily influenced. But, what about our eyes?

I’ve seen numerous accounts of people witnessing a crime (for instance), then reporting what occurred. Even those standing within proximity will describe the scene differently. “The man had on a long, black coat.” The next person says, “No, he had on a long gray coat with a hood.” “It was definitely a man,” says one witness. While another states, “It was a tall woman!” So, who was right and who was wrong?

Most people have experienced the phenomenon of something catching their attention, only to discover that someone next to them completely missed what seemed obvious. Neuroscientists have grappled with the question of why two people remember different and sometimes mutually exclusive details about the same scene.

This century-old scientific question of visual processing has been partially answered in a new study published by researchers from the University of California, Davis, and Otto-von-Guericke University in Magdeburg, Germany. 

The international team found that the way individual brains register, and process visual information depends upon where individuals direct their attention. In other words, paying attention to one part of a complex scene effectively boosts those visual brain signals while weakening signals from other parts of the scene. The study is the first to successfully pair two functional brain-imaging techniques to describe a mechanism of human cognition. The researchers combined a modern noninvasive method that accurately measures when brain activity occurs with a method that pinpoints where the activity occurs. “Attention has powerful implications for our everyday perceptions,” said Ron Mangun, a psychology professor at the UC Davis Center for Neuroscience and co-author of the study. “When people pay attention to something in the world around them, it changes the way their brains process that and other visual information coming into the brain.” This is known as selective attention — paying attention to one thing while ignoring others. Selective attention is an essential brain process that keeps us focused on the most important items at the moment but can also lead to failures of perception — such as when we fail to detect a stop sign while concentrating on the road ahead. The study by Mangun, Hans-Jochen Heinze, professor of clinical neurophysiology at the Otto-von-Guericke University, and their colleagues shows that selective visual attention kicks in as fast as 80 milliseconds after the retina at the back of the eyeball sends an exact copy of the visual world to the brain for visual processing. In a brain region known as the “extrastriate visual cortex” in the lower back of each half of the brain, the selected visual stimuli receive enhanced visual processing. According to this study, the flow of information from the eye to higher brain areas is altered at this relatively early stage. “Experimental psychologists have known for more than 100 years that perceptions are influenced by desires, momentary needs and intent,” Heinze said…

And back to ears, what about this famous clip, Yanny vs Laurel?

So why do people hear two distinct sounds?

Nina Kraus, a neurobiology professor at Northwestern University, says, “It is not at all surprising to me that two different people will take a sound that is admittedly acoustically ambiguous and hear it differently.”

“Acoustically ambiguous” in this case means that it’s a very poor-quality file. That is crucial in explaining why people are hearing different things.

The viral tweet posted by Feldman was actually taken from a post on Reddit, as she has explained. And the person who appears to be the original Reddit poster, RolandCamry, says that he made it from playing a recording from Vocabulary.com out of his speakers. In other words, there are multiple steps that degrade the quality of the audio.

(Spoiler alert: Based on what the Redditor who claims to be the original poster said, the original recording is probably this one on Vocabulary.com, which says “laurel.”)

The poor quality of the audio, likely re-recorded multiple times, makes it more open to interpretation by the brain, says Brad Story, a professor of speech, language and hearing sciences at the University of Arizona. Primary information that would be present in a high-quality recording or in person is “weakened or attenuated,” Story says, even as the brain is eagerly looking for patterns to interpret.

“And if you throw things off a little bit, in terms of it being somewhat unnatural, then it is possible to fool that perceptual system and our interpretation of it,” says Story.

There can be several reasons why someone hears something different from another person. These include:

Perception: Each person’s perception of sound can differ based on age, hearing ability, and sensitivity to certain frequencies. This can cause some people to hear sounds differently than others, even when they are listening to something identical.

Attention: A person’s level of attention can affect what they hear. If they are distracted or not fully engaged, they may miss certain words, phrases, or sentences.

Context: The context in which a conversation takes place can also affect what a person hears. If someone is expecting to hear something specific, they may interpret the words differently than someone who has no preconceived notions.

Language barriers: If there is a language barrier exists between the two people, then it can be difficult to accurately understand each other, especially if there are cultural or regional differences.

Noise interference: Background noise or interference can also affect what a person hears. If there is a lot of noise in the environment, it can be difficult to distinguish between different sounds and words.