What you hear could depend on what your hands are doing

New research links motor skills and perception, specifically as it relates to a second finding—a new understanding of what the left and right brain hemispheres "hear." Georgetown University Medical Center researchers say these findings may eventually point to strategies to help stroke patients recover their language abilities, and to improve speech recognition in children with dyslexia.

The study, presented at Neuroscience 2012, the annual meeting of the Society for Neuroscience, is the first to match with left brain/right brain auditory processing tasks. Before this research, neuroimaging tests had hinted at differences in such processing.

"Language is processed mainly in the left hemisphere, and some have suggested that this is because the left hemisphere specializes in analyzing very rapidly changing sounds," says the study's senior investigator, Peter E. Turkeltaub, M.D., Ph.D., a in the Center for and Recovery. This newly created center is a joint program of Georgetown University and MedStar National Rehabilitation Network.

Turkeltaub and his team hid rapidly and slowly changing sounds in and asked 24 volunteers to simply indicate whether they heard the sounds by pressing a button.

"We asked the subjects to respond to sounds hidden in background noise," Turkeltaub explained. "Each subject was told to use their right hand to respond during the first 20 sounds, then their left hand for the next 20 second, then right, then left, and so on." He says when a subject was using their right hand, they heard the rapidly changing sounds more often than when they used their left hand, and vice versa for the slowly changing sounds.

"Since the left hemisphere controls the right hand and vice versa, these results demonstrate that the two hemispheres specialize in different kinds of sounds—the left hemisphere likes rapidly changing sounds, such as , and the likes slowly changing sounds, such as syllables or intonation," Turkeltaub explains. "These results also demonstrate the interaction between motor systems and perception. It's really pretty amazing. Imagine you're waving an American flag while listening to one of the presidential candidates. The speech will actually sound slightly different to you depending on whether the flag is in your left hand or your right hand."

Ultimately, Turkeltaub hopes that understanding the basic organization of auditory systems and how they interact with motor systems will help explain why language resides in the left hemisphere of the brain, and will lead to new treatments for language disorders, like aphasia (language difficulties after stroke or brain injury) or dyslexia.

"If we can understand the basic brain organization for audition, this might ultimately lead to new treatments for people who have speech recognition problems due to stroke or other brain injury. Understanding better the specific roles of the two hemispheres in auditory processing will be a big step in that direction. If we find that people with aphasia, who typically have injuries to the , have difficulty recognizing speech because of problems with low-level auditory perception of rapidly changing sounds, maybe training the specific auditory processing deficits will improve their ability to recognize speech," Turkeltaub concludes.

Related Stories

Adults with dyslexia have problems with non-speech sounds too

Jun 01, 2010

(PhysOrg.com) -- Dyslexia is usually associated with persistent reading, spelling, and sometimes speech difficulties that are hard to overcome. One theory proposed to explain the condition is that people with dyslexia suffer ...

Where the brain makes sense of speech

Dec 19, 2007

Researchers have identified regions of the brain where speech sounds are perceived as having abstract meaning, rather than as just a stream of sensory input. They said their identification of the regions demonstrates that ...

Recommended for you

New research supporting stroke rehabilitation

11 hours ago

Using world-leading research methods, the team of Dr David Wright and Prof Paul Holmes, working with Dr Jacqueline Williams from the Victoria University in Melbourne, studied activity in an area of the brain ...

Team finds an off switch for pain

16 hours ago

In research published in the medical journal Brain, Saint Louis University researcher Daniela Salvemini, Ph.D. and colleagues within SLU, the National Institutes of Health (NIH) and other academic institutions have d ...

Brain researchers pinpoint gateway to human memory

18 hours ago

An international team led by researchers of the University of Magdeburg and the DZNE has successfully determined the location, where memories are generated with a level of precision never achieved before. ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Tausch
not rated yet Oct 14, 2012
lol
Yes. I play piano. I switch (cross over my arms)to play the same piece of music with the hands now performing the original music with the left hand playing the right hand's role and vice versa.

j/k
You are correct. Basic brain organization for audition starts with conception. Fetal/embryonic motor/audition development get their 'cues' for development long before these innate functions mature to serve as the functions they are intended to perform at birth.

You will experience a delay in your understanding if lateralization of brain function is paramount to your understanding.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.