Summary: While listening to audiobooks with a captivating narrative, the inferior parietal lobe and visual cortex elicit individual meaning and flow of mental imagery.
Source: Aalto University
Researchers at Aalto University analysed how listeners immerse themselves in audiobooks by using functional magnetic resonance imaging (fMRI) and words that the story brings to mind. The study indicated that word lists resembling each other also predicted similarities in brain function.
In the study, 16 people listened to an audiobook written by Professor Iiro Jääskeläinen inside an fMRI device. After this, the same people listened to the story again in sections lasting between 3 and 5 seconds, and listed the words that came to their mind while they were listening.
For example, the following line in the story ‘went towards the bedroom door’ may, to some people, bring to mind a door handle, walking and a bedroom, while another person may recall a television, home and their favourite TV series. The visual images may also be different.
‘Instead of focusing on individual statements, the study examined immersion, or similarity in brain activity, in relation to the entire story’, Jääskeläinen says.
Word lists produced by the research subjects were assessed using a semantic tree and latent semantic analysis. In a semantic tree, dots represent concepts and arcs portray the relationships between concepts. For example, the words ‘dog’, ‘canine’ and ‘spaniel’ are close to each other in the tree, while ‘dog’ and ‘submarine’ are far apart. On the basis of this, estimations were made on how far the research subjects’ word lists were from each other.
Scientists discovered that similar words in the list predicted similarities in the test subjects’ brain activity, particularly in the area between the temporal and parietal lobe, which is important in language processing, and the visual cortex.
‘In the future, it will be interesting to see if this is caused by, for instance, cultural or personality differences’, Iiro Jääskeläinen says.
In meantime, the new method has various potential research applications: such as measuring creativity and its neural basis; or how people with different cultural backgrounds interpret the world in different ways.
Iiro Jääskeläinen – Aalto University
The image is in the public domain.
Original Research: Open access.
“Inferior parietal lobule and early visual areas support elicitation of individualized meanings during narrative listening”
Satu Saalasti, Jussi Alho, Moshe Bar, Enrico Glerean, Timo Honkela, Minna Kauppila, Mikko Sams, Iiro P. Jääskeläinen Brain and Behavior doi:10.1002/brb3.1288
Inferior parietal lobule and early visual areas support elicitation of individualized meanings during narrative listening
When listening to a narrative, the verbal expressions translate into meanings and flow of mental imagery. However, the same narrative can be heard quite differently based on differences in listeners’ previous experiences and knowledge. We capitalized on such differences to disclose brain regions that support transformation of narrative into individualized propositional meanings and associated mental imagery by analyzing brain activity associated with behaviorally assessed individual meanings elicited by a narrative.
Sixteen right‐handed female subjects were instructed to list words that best described what had come to their minds while listening to an eight‐minute narrative during functional magnetic resonance imaging (fMRI). The fMRI data were analyzed by calculating voxel‐wise intersubject correlation (ISC) values. We used latent semantic analysis (LSA) enhanced with Wordnet knowledge to measure semantic similarity of the produced words between subjects. Finally, we predicted the ISC with the semantic similarity using representational similarity analysis.
We found that semantic similarity in these word listings between subjects, estimated using LSA combined with WordNet knowledge, predicting similarities in brain hemodynamic activity. Subject pairs whose individual semantics were similar also exhibited similar brain activity in the bilateral supramarginal and angular gyrus of the inferior parietal lobe, and in the occipital pole.
Our results demonstrate, using a novel method to measure interindividual differences in semantics, brain mechanisms giving rise to semantics and associated imagery during narrative listening. During listening to a captivating narrative, the inferior parietal lobe and early visual cortical areas seem, thus, to support elicitation of individual meanings and flow of mental imagery.