Finding thoughts in speech

Memory- or self-related content? The researchers analysed content-specific neural responses and observed clearly visible patterns of brain activity. Credit: BrainLinks-BrainTools

For the first time, neuroscientists were able to find out how different thoughts are reflected in neuronal activity during natural conversations. Johanna Derix, Olga Iljina and the interdisciplinary team of Dr. Tonio Ball from the Cluster of Excellence BrainLinks-BrainTools at the University of Freiburg and the Epilepsy Center of the University Medical Center Freiburg (Freiburg, Germany) report on the link between speech, thoughts and brain responses in a special issue of Frontiers in Human Neuroscience.

"Thoughts are difficult to investigate, as one cannot observe in a direct manner what the person is thinking about. Language, however, reflects the underlying mental processes, so we can perform linguistic analyses of the subjects' speech and use such information as a "bridge" between the neuronal processes and the subject's thoughts," explains neuroscientist Johanna Derix..

The novelty of the authors' approach is that the participants were not instructed to think and talk about a given topic in an experimental setting. Instead, the researchers analysed everyday conversations and the underlying brain activity, which was recorded directly from the cortical surface. This study was possible owing to the help of epilepsy patients in whom recordings of neural activity had to be obtained over several days for the purpose of pre-neurosurgical diagnostics.

For a start, borders between individual thoughts in continuous conversations had to be identified. Earlier psycholinguistic research indicates that a simple sentence is a suitable unit to contain a single thought, so the researchers opted for linguistic segmentation into simple sentences. The resulting "idea" units were classified into different categories. These included, for example, whether or not a sentence expressed memory- or self-related content. Then, the researchers analysed content-specific neural responses and observed clearly visible patterns of .

Thus, the from Freiburg have demonstrated the feasibility of their innovative approach to investigate, via speech, how the human brain processes during real-life conditions.

More information: Derix J, Iljina O, Weiske J, Schulze-Bonhage A, Aertsen A and Ball T (2014).. From speech to thought: "The neuronal basis of cognitive units in non-experimental, real-life communication using ECoG." Front. Hum. Neurosci. 8:383. DOI: 10.3389/fnhum.2014.00383. http://journal.frontiersin.org/Journal/10.3389/fnhum.2014.00383/abstract

add to favorites email to friend print save as pdf

Related Stories

How your brain works during meditation

May 15, 2014

Mindfulness. Zen. Acem. Meditation drumming. Chakra. Buddhist and transcendental meditation. There are countless ways of meditating, but the purpose behind them all remains basically the same: more peace, ...

A light switch inside the brain

Jan 18, 2013

Activating and deactivating individual nerve cells in the brain is something many neuroscientists wish they could do, as it would help them to better understand how the brain works.

Study: Speech processing requires both sides of our brain

Jan 15, 2014

We use both sides of our brain for speech, a finding by researchers at New York University and NYU Langone Medical Center that alters previous conceptions about neurological activity. The results, which appear ...

Recommended for you

The brain's electrical alphabet

Jan 23, 2015

The brain's alphabet is a mix of rate and precise timing of electrical pulses: the observation was made by researchers at the International School for Advanced Studies (SISSA) of Trieste and the Italian Institute ...

Dragnet for epilepsy genes

Jan 23, 2015

An international team of scientists together with the University of Bonn Hospital have taken a new path in the research into causes of epilepsy: The researchers determined the networks of the active genes ...

The molecular biology behind ALS

Jan 23, 2015

UA researchers have identified a molecular defect in motor neurons that may help explain the mechanisms underlying ALS, or Lou Gehrig's Disease.

User 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.