Study suggests the mind flexibly joins the meanings of individual words to form structured thoughts

August 25, 2015 by Bob Yirka, Medical Xpress report
Credit: Wikimedia Commons

(Medical Xpress)—A pair of researchers with Harvard University has found evidence that supports the idea that the human mind flexibly merges the meanings of single words to form or compose structured thoughts. In their paper published in Proceedings of the National Academy of Sciences, Steven Frankland and Joshua Greene describe the study they conducted and why they believe what they learned helps in understanding how the human thought process works.

It has often been noted that allow people to create and envision an of ideas using a finite number of words. But how we do that is still, of course, a mystery. In this new effort, Frankland and Greene conducted some MRI tests on volunteers to see if they could learn more about how the process works.

The research duo ran two types of tests, first 18 volunteers were asked to undergo MRI scans as they read short sentences that could be interpreted in either passive or active voice, or which could be arranged to have an opposite meaning, such as "the cat scratched the girl," versus "the girl scratched the cat." Next 34 other volunteers were asked to undergo MRI scans while reading sentences made up of just four nouns ( dog, cat, girl and man) and five verbs (approached, chased, blocked, scratched and bumped) along with a connector, e.g. "the girl approached the man."

By examining a part of the brain known as the left mid-superior temporal cortex, as the volunteers read their sentences, the researchers were able to note that neurons fired differently depending on context, which they suggest corresponded to the mind separating contextual ideas into different types of meaningfulness, such as "Who did something?" and "Who was it done to?" This, they conclude, suggests the mind works in a way similar to computers processing information—with distinctions being made between information that is held in variables versus the variables themselves. They liken thought interpretation in the brain to usage of slots, with different types of contextual information being routed to the correct slot for processing.

The researchers also note that they are not suggesting that all language and idea processing is done in the left mid-superior temporal cortex—only that it appears to play a central role.

Explore further: Researchers find reading uses the same brain regions regardless of language

More information: An architecture for encoding sentence meaning in left mid-superior temporal cortex, Steven M. Frankland, DOI: 10.1073/pnas.1421236112

Abstract
Human brains flexibly combine the meanings of words to compose structured thoughts. For example, by combining the meanings of "bite," "dog," and "man," we can think about a dog biting a man, or a man biting a dog. Here, in two functional magnetic resonance imaging (fMRI) experiments using multivoxel pattern analysis (MVPA), we identify a region of left mid-superior temporal cortex (lmSTC) that flexibly encodes "who did what to whom" in visually presented sentences. We find that lmSTC represents the current values of abstract semantic variables ("Who did it?" and "To whom was it done?") in distinct subregions. Experiment 1 first identifies a broad region of lmSTC whose activity patterns (i) facilitate decoding of structure-dependent sentence meaning ("Who did what to whom?") and (ii) predict affect-related amygdala responses that depend on this information (e.g., "the baby kicked the grandfather" vs. "the grandfather kicked the baby"). Experiment 2 then identifies distinct, but neighboring, subregions of lmSTC whose activity patterns carry information about the identity of the current "agent" ("Who did it?") and the current "patient" ("To whom was it done?"). These neighboring subregions lie along the upper bank of the superior temporal sulcus and the lateral bank of the superior temporal gyrus, respectively. At a high level, these regions may function like topographically defined data registers, encoding the fluctuating values of abstract semantic variables. This functional architecture, which in key respects resembles that of a classical computer, may play a critical role in enabling humans to flexibly generate complex thoughts.

Related Stories

Researchers find reading uses the same brain regions regardless of language

November 27, 2012
(Medical Xpress)—A team of French and Taiwanese researchers has found evidence to indicate that people use the same regions of the brain when reading, regardless of which language is being read. In their paper published ...

Study shows link between teen impatience and neural development in the brain

June 23, 2015
(Medical Xpress)—A team of researchers with members from the U.S. and Germany has found a connection between neural development in one part of the brain and teen impatience. In their paper published in Proceedings of the ...

Study shows people capable of reading and solving math equations subconsciously

November 13, 2012
(Medical Xpress)—Researchers at Hebrew University in Jerusalem have found that contrary to popular thinking, people are capable of reading sentences and solving math problems without consciously thinking about them. The ...

Study shows mirror image scratching offers some relief

January 28, 2014
(Medical Xpress)—A study of mirrors and the tricks they can play on the mind has led to a finding that people scratching a mirror image of an arm instead of the one that truly itches, can provide some relief. In their paper ...

Recommended for you

Psychiatric disorders share an underlying genetic basis

June 21, 2018
Psychiatric disorders such as schizophrenia and bipolar disorder often run in families. In a new international collaboration, researchers explored the genetic connections between these and other disorders of the brain at ...

One year of school comes with an IQ bump, meta-analysis shows

June 21, 2018
A year of schooling leaves students with new knowledge, and it also equates with a small but noticeable increase to students' IQ, according to a systematic meta-analysis published in Psychological Science, a journal of the ...

Ketamine acts fast to treat depression and its effects last—but how?

June 21, 2018
In contrast to most antidepressant medications, which can take several weeks to reduce depressive symptoms, ketamine—a commonly used veterinary anesthetic—can lift a person out of a deep depression within minutes of its ...

New study debunks Dale Carnegie advice to 'put yourself in their shoes'

June 21, 2018
Putting yourself in someone else's shoes and relying on intuition or "gut instinct" isn't an accurate way to determine what they're thinking or feeling," say researchers from Ben-Gurion University of the Negev (BGU), the ...

Mindful movement may help lower stress, anxiety

June 21, 2018
Taking a walk may be a good opportunity to mentally review your to-do list, but using the time to instead be more mindful of your breathing and surroundings may help boost your wellbeing, according to researchers.

Brain tingles—first study of its kind reveals physiological benefits of ASMR

June 21, 2018
Autonomous sensory meridian response (ASMR) – the relaxing 'brain tingles' experienced by some people in response to specific triggers, such as whispering, tapping and slow hand movements – may have benefits for both ...

0 comments

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.