Neurocognitive studies of human vocal communication

点击翻译按钮获取中文摘要

As we talk to another person, how does our brain respond to a speaker's tone of voice over time to derive different types of meaning? For instance, how do we interpret a speaker's emotions, their attitudes, or their confidence level based on how they express themselves through their voice? And how does the brain make sense of a communicative situation based on how another person speaks (their vocal expression) and what they are saying (the linguistic message)? Changes in the pitch, loudness, and quality of a person's voice convey a variety of meanings during interpersonal communication and fundamentally affect how we relate to one another. Our ability to engage in complex vocal behaviour is quintessentially human, and arguably at the root of our success as a species, and yet we are limited in our knowledge of how vocal expressions are processed in the brain. The goal of this research is to shed light on the unique human subsystem for vocal communication; we will demonstrate how people make sense of a speaker's tone of voice in everyday situations involving spoken language and relate these details to functions and structures of the human brain. Our studies probe these questions by investigating how adult listeners evaluate the emotional and social significance of vocal expressions and make decisions based on voice-related speech cues. We will perform experiments in which vocal expressions convey the speaker's emotions (e.g., happy, sad), their confidence level (e.g., confident, doubtful), or in which speakers use vocal expressions to alert the listener that they mean something different than what they are saying (e.g., innuendo). We use a range of methods in our experiments: we ask listeners to judge utterances produced in different ways to determine what impressions they create, and we conduct acoustic analyses to describe their physical form. Many of our studies present utterances as we record electrical activity or blood flow in a listener's brain, to determine what mental operations act on a speaker's tone of voice and what brain systems are involved. This work will give us new details about how people understand another person's goals and intentions in light of how a speaker uses their voice. The impacts and potential applications of our work are many. The knowledge we create will inspire scientists in several intersecting fields, such as neuroscience, psychology, and engineering, to undertake new work that refines perspectives about human interpersonal behaviour. By demonstrating how people use tone of voice in everyday situations, speech technologies that rely on human-machine interactions (e.g., Siri, Alexa) may be vastly improved to the benefit of society. Knowledge of how the brain is involved in complex forms of "social communication" will also help clinical scientists to design intervention strategies for individuals with social communication difficulties (e.g., people with autism spectrum disorders) with positive health benefits.