The Man Who Hears People Before They Speak
2013 07 08

By Helen Thomson | NewScientist



"I told my daughter her living room TV was out of sync. Then I noticed the kitchen telly was also dubbed badly. Suddenly I noticed that her voice was out of sync too. It wasn’t the TV, it was me."

Ever watched an old movie, only for the sound to go out of sync with the action? Now imagine every voice you hear sounds similarly off-kilter – even your own. That’s the world PH lives in. Soon after surgery for a heart problem, he began to notice that something wasn’t quite right.


"I was staying with my daughter and they like to have the television on in their house. I turned to my daughter and said ’you ought to get a decent telly, one where the sound and programme are synchronised’. I gave a little chuckle. But they said ’there’s nothing wrong with the TV’."

Puzzled, he went to the kitchen to make a cup of tea. "They’ve got another telly up on the wall and it was the same. I went into the lounge and I said to her ’hey you’ve got two TVs that need sorting!’."

That was when he started to notice that his daughter’s speech was out of time with her lip movements too. "It wasn’t the TV, it was me. It was happening in real life."

PH is the first confirmed case of someone who hears people speak before registering the movement of their lips. His situation is giving unique insights into how our brains unify what we hear and see.

It’s unclear why PH’s problem started when it did – but it may have had something to do with having acute pericarditis, inflammation of the sac around the heart, or the surgery he had to treat it.

Brain scans after the timing problems appeared showed two lesions in areas thought to play a role in hearing, timing and movement. "Where these came from is anyone’s guess," says PH. "They may have been there all my life or as a result of being in intensive care."

Disconcerting delay

Several weeks later, PH realised that it wasn’t just other people who were out of sync: when he spoke, he registered his words before he felt his jaw make the movement. "It felt like a significant delay, it sort of snuck up on me. It was very disconcerting. At the time I didn’t know whether the delay was going to get bigger, but it seems to have stuck at about a quarter of a second."

Light and sound travel at different speeds, so when someone speaks, visual and auditory inputs arrive at our eyes and ears at different times. The signals are then processed at different rates in the brain. Despite this, we normally perceive the events as happening simultaneously – but how the brain achieves this is unclear.

To investigate PH’s situation, Elliot Freeman at City University London and colleagues performed a temporal order judgement test. PH was shown clips of people talking and was asked whether the voice came before or after the lip movements. Sure enough, he said it came before, and to perceive them as synchronous the team had to play the voice about 200 milliseconds later than the lip movements.

The team then carried out a second, more objective test based on the McGurk illusion. This involves listening to one syllable while watching someone mouth another; the combination makes you perceive a third syllable.

Since PH hears people speaking before he sees their lips move, the team expected the illusion to work when they delayed the voice. So they were surprised to get the opposite result: presenting the voice 200 ms earlier than the lip movements triggered the illusion, suggesting that his brain was processing the sight before the sound in this particular task.

And it wasn’t only PH who gave these results. When 37 others were tested on both tasks, many showed a similar pattern, though none of the mismatches were noticeable in everyday life.

Many clocks

Freeman says this implies that the same event in the outside world is perceived by different parts of your brain as happening at different times. This suggests that, rather than one unified "now", there are many clocks in the brain – two of which showed up in the tasks – and that all the clocks measure their individual "nows" relative to their average.

[...]

Read the full article at: newscientist.com




Related Articles
Decoding Space and Time in the Brain
"Laws of Physics for a Holographic Universe" --New Theories of Space-Time
The Brain’s Stopwatch – Emotions and Time Perception
Why Time is a Social Construct
Mind reading Sharjah Girl ‘exceedingly rare’ savant
Fractal Minds and the Sacred Cosmology : Neuroscience & Psychology meets Esoteric Religion


Latest News from our Front Page

6,000-Year-Old Temple with Possible Sacrificial Altars Discovered
2014 10 21
A 6,000-year-old temple holding humanlike figurines and sacrificed animal remains has been discovered within a massive prehistoric settlement in Ukraine. Built before writing was invented, the temple is about 60 by 20 meters (197 by 66 feet) in size. It was a "two-story building made of wood and clay surrounded by a galleried courtyard," the upper floor divided into five ...
What happened to Journalist Serena Shim? Assassinated? Find out what happened to Serena, Press TV director calls on Turkey
2014 10 21
Press TV news director Hamid Reza Emadi says the “suspicious death,” of the news channel’s correspondent in Turkey is a tragedy for “anyone who wants to get the truth.” Emadi made the remarks in an interview with Press TV on Sunday following Serena Shim’s death across the border from Syria’s Kurdish city of Kobani, where the ISIL terrorists and Kurdish fighters ...
Ancient Roman Nanotechnology Inspires Next-Generation Holograms for Information Storage
2014 10 21
The Lycurgus Cup, as it is known due to its depiction of a scene involving King Lycurgus of Thrace, is a 1,600-year-old jade green Roman chalice that changes colour depending on the direction of the light upon it. It baffled scientists ever since the glass chalice was acquired by the British Museum in the 1950s, as they could not work ...
Rapid Geomagnetic Reversal Possibility: Confirmed
2014 10 21
From the video: "The scientists who conducted the study are still unsure why the magnetic field is weakening, but one likely reason is the Earth’s magnetic poles are getting ready to flip, said Rune Floberghagen, the ESA’s Swarm mission manager. In fact, the data suggest magnetic north is moving toward Siberia." Tune into Red Ice Radio: Ben Davidson - Suspicious0bservers: Space Weather ...
Georgia Guide Stone 2014 cube stone removal
2014 10 21
From: Youtube: Was it all just a gag? it seems the cube stone just happens to be made out of the same Elberton granite that the rest of this morbid monument is made from.
More News »