Brain mechanisms to recognize individuals by vocalizations: Comparison between Japanese macaques and humans

2018 Fiscal Year Final Research Report

• Project/Area Number: 17H07234
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Perceptual information processing
• Research Institution: Doshisha University
• Principal Investigator: Furuyama Takafumi 同志社大学, 研究開発推進機構, 特別研究員 (20802268)
• Project Period (FY): 2017-08-25 – 2019-03-31
• Keywords: EEG / 個体識別 / 霊長類 / Mismatch negativity / 発声音声 / 音声コミュニケーション

Outline of Final Research Achievements

The both of meaning and individual recognition in vocalizations are important to maintain social structures when we communicate each other by using voices. The purpose of this study was to investigate acoustic properties and brain regions to discriminate individuals in Japanese macaques. The fifteen silver plate electrodes were set to a head skin in subject. We determined each position following the study of standard EEG in humans, called 10-20 systems. The vocalizations of Monkey A and B were presented and the data of brain waveforms was analyzed by using EEGLAB. The brain waveforms were recorded at each position, and we calculated the difference of responses between deviant and standard. As our results, the most of mismatch negative (MMN) responses was observed at 200 ms after stimulus in anterior position. This result was same results of MMN in previous study of humans. Our results showed that the vocal recognition of monkeys was similar to that of humans.

Free Research Field

神経行動学

Academic Significance and Societal Importance of the Research Achievements

ヒトを含む多くの霊長類は、野外環境下で複雑な個体関係にもとづいた社会を構成している。そのような動物にとって音声による個体識別は社会コミュニケーションを維持するために極めて重要である。本研究の成果から、ニホンザルも音声のみで発声個体を識別するための脳内機構は、ヒトと同様である可能性が示唆された。今後、音声による個体識別の脳内機構と視覚による個体識別の脳内機構を比較することで、初めてヒトやサルが自然場面でおこなう個体識別の全容が解明できると考える。