Summary: Researchers discovered that neural activity in the left ventral temporoparietal junction (vTPJ) and the lateral anterior temporal lobe (lATL) during sentence processing is tied to social-semantic working memory.
Previously, these regions were attributed to general language processing. Using fMRI experiments, the study demonstrated that these regions respond to sentences with social meaning and maintain activity even after the linguistic stimulus is gone. This insight reshapes our understanding of the brain’s cortical language network.
The left vTPJ and lATL are connected to social-semantic working memory, not just language.
Activity in these regions persists after linguistic stimuli disappear, showcasing their role in retaining social meaning.
This revelation prompts a reevaluation of the brain’s language network and enhances social neuroscience.
Source: Chinese Academy of Science
A research team led by Prof. LIN Nan from the Institute of Psychology of the Chinese Academy of Sciences found that during sentence processing, the neural activity of two canonical language areas, i.e., the left ventral temporoparietal junction (vTPJ) and the lateral anterior temporal lobe (lATL), is associated with social-semantic working memory rather than language processing per se.
The study was published in Nature Human Behaviour on Sept. 21.
Language and social cognition are two deeply interrelated abilities of the human species, but have traditionally been studied as two separate domains. Both sentence processing and social tasks can evoke neural activity in the left vTPJ and lATL, suggesting that the function of these regions may link language comprehension with social cognition.
However, previous studies have attributed the activity of these regions in language tasks to general semantic and/or syntactic processing, whereas their activity in social tasks is attributed to social concept activation.
In this study, the researchers tested a novel hypothesis that the activity of the left vTPJ and lATL in language and social tasks are both due to a common cognitive component—i.e., social-semantic working memory.
Using fMRI experiments, they validated that these regions were sensitive to sentences only if the sentences conveyed social meaning. In addition, these regions showed persistent social-semantic-selective activity after the linguistic stimuli disappeared and were sensitive to the sociality of nonlinguistic stimuli. Furthermore, these regions were more tightly connected to the social-semantic-processing areas than to the sentence-processing areas.
The results indicate that the left vTPJ and lATL are not specific to language processing and contribute to language comprehension through social-semantic working memory.
“Since the 1990s, it has been consistently observed that the left vTPJ and lATL are sensitive to sentence processing. Therefore, our findings were quite surprising,” said Prof. LIN, corresponding author of the study.
These findings are likely to force a major reconsideration of the functional organization of the cortical language network, and they also make an important new contribution to the field of social neuroscience, according to a reviewer for Nature Human Behaviour.
Funding: This study was supported by the National Natural Science Foundation of China, the Scientific Foundation of the Institute of Psychology, and the National Science and Technology Innovation 2030 Major Program.
About this language and social neuroscience research news
A social-semantic working-memory account for two canonical language areas
Language and social cognition are traditionally studied as separate cognitive domains, yet accumulative studies reveal overlapping neural correlates at the left ventral temporoparietal junction (vTPJ) and the left lateral anterior temporal lobe (lATL), which have been attributed to sentence processing and social concept activation. We propose a common cognitive component underlying both effects: social-semantic working memory.
We confirmed two key predictions of our hypothesis using functional MRI. First, the left vTPJ and lATL showed sensitivity to sentences only when the sentences conveyed social meaning; second, these regions showed persistent social-semantic-selective activity after the linguistic stimuli disappeared.
We additionally found that both regions were sensitive to the socialness of non-linguistic stimuli and were more tightly connected with the social-semantic-processing areas than with the sentence-processing areas.
The converging evidence indicates the social-semantic working-memory function of the left vTPJ and lATL and challenges the general-semantic and/or syntactic accounts for the neural activity of these regions.