The extrastriate body area is involved in reciprocal imitation of hand gestures, vocalizations, and facial expressions: A univariate and multivariate fMRI study

ABSTRACT

The extrastriate body area (EBA) in the lateral occipito-temporal cortex has an important role in reciprocal interaction, as it detects congruence between self and other’s hand actions. However, it is unclear whether the EBA can detect congruence regardless of the type of action. In the present study, we examined the neural substrate underlying congruence detection of three types of actions: hand gestures, vocalizations, and facial expressions. A univariate analysis revealed a congruency effect, especially for imitating action, for all three types of actions in the EBA. A multi-voxel pattern analysis classifier in the EBA was able to distinguish between initiating interaction from responding to interaction in all experiments. Correspondingly, the congruency effect in the EBA revealed by univariate analysis was stronger for responding to than for initiating interaction. These findings suggest that the EBA might contribute to detect congruence regardless of the body part used (i.e. face or hand) and the type of action (i.e. gestural or vocal). Moreover, initiating and responding to interaction might be processed differently within the EBA. This study highlights the role of the EBA in comparing between self and other’s actions beyond hand actions.

Running head: Function of EBA in reciprocal imitation

KEYWORDS:

• fMRI
• reciprocal imitation
• EBA
• hand gesture
• vocalization
• facial expression

Acknowledgments

We thank M. Yamazaki (Murase) for conducting experiment.

Disclosure Statement

The authors declare that they have no competing interests.

Data availability statement

The datasets generated and analyzed during the current study are not publicly available because reuse of the data was not intended when we received approval from our ethics committee.

Additional information

Funding

This work was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science to Y. Okamoto (17K17766), Grant-in-Aid for JSPS Fellows to Y.Okamoto (10J01339) and the project “Development of biomarker candidates for social behavior” and “Integrated research on neuropsychiatric disorders” carried out under the Strategic Research Program for Brain Sciences by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT) to N.Sadato.