Auditory Development

Lab

2017 Newsletter

The Auditory Development Lab studies the perception of sound in infants, children, and adults, as well as the acquisition of music and language. Here is a summary of recent research findings.

Did you know that when you bop around to music with your baby, this makes them little helpers? Laura Cirelli, PhD Our research has shown that 14-month-old babies are more likely to help someone out after moving to music with them. In these experiments, an assistant holds the baby and gently bounces them to the song “Twist and Shout”. The experimenter stands facing the baby and either bounces in synchrony with them or out-of-synchrony (to a different tempo). After bouncing, the experimenter performs a few tasks, like drawing pictures or throwing balls in a bucket. She pretends to accidentally drop the objects she is using to complete these tasks, and we measure whether the babies actually toddle over, pick these objects up, and hand them back to her. We have found that infants actually hand back more objects if they bounced in sync versus out of sync with this experimenter! Will bounced babies help other people, too? We found that bouncing in vs. out-of-sync with the experimenter also makes the babies more willing to help this person’s friend! However, synchronous bouncing did not influence helpfulness towards a neutral stranger. This tells us that babies want to affiliate both with their synchronous partner AND with members of that person’s social group! How important is music to this experience? We found that music is not necessary for this boost in helping to show up. If we replace music with nature sounds, the in-sync babies are still more helpful. But without music, our little junior scientists enjoyed the experience less – more of them didn’t want to complete the experiment, and helping rates were lower than usual. So while music may not be necessary to boost helpfulness in bouncing babies, it certainly makes the in-sync bouncing experience a more enjoyable one! Do babies expect in-sync bouncers to be friends? We wanted to know whether babies expect in-sync people to be friendly to each other, and out-of-sync people to be unfriendly to each other. To measure expectation in these babies, we record how long they watch different kinds of videos. 12- and 14-month-old infants watch videos of two women either bouncing in sync or out-of-sync with each other to music. After watching the women bounce together, we show them a video of these two women being friendly and waving at each other, and a video of them being unfriendly, turning away and crossing their arms. If babies expect two people to be friends, they should be surprised and look longer at the unfriendly interactions. If they expect two people to be unfriendly, they should find the friendly interaction surprising. Babies in both age groups don’t show any specific expectation for synchronous movers, but they are surprised to see out-of-sync bouncers acting like friends!

How do we measure what infants expect? Often, researchers test infants’ expectations by measuring how long they watch two displays. Infants generally look longer at events that are surprising than events that are unsurprising. If a baby expects that bouncing in-sync means two people are friends, they should look longer at a video where those

bouncers are unfriendly (which would be surprising) than a video where they’re being friendly (unsurprising).

Dr. Laurel Trainor, Director

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When does metric structure develop? Laura Cirelli, PhD When we listen to music, we can pretty easily tap our feet or bop our heads to the steady underlying beat. We also tend to group these beats into what we call a “metric structure”. For example, when we are listening to a march we think about the beats like “1 2, 1 2, 1 2” but when we are listening to a waltz we think about the beats like “1 2 3, 1 2 3, 1 2 3”. Over the past 2 years, we have been using electroencephalography (EEG) to look at how babies group musical beats. EEG is a safe and easy way for us to measure the resting brain activity of a baby using little spongy sensors that sit on the scalp. By measuring infants’ brain responses while they listen to simple rhythm patterns, we can tell whether or not they are grouping the beats into groups of two (like a march) or groups of three (like a waltz). Results from our lab show that babies as young as 7 months show clear responses to the beat and the metrical structure of a rhythmic pattern. But we also learned that the strength of the response was shaped in part by their musical backgrounds. Seven-month old babies who had taken part in infant music classes had stronger metric responses than seven-month-olds who had not. Fourteen-month-old babies with parents who were more musically trained had larger beat and metric responses than babies with musically untrained parents. Right now we are investigating how listening to natural music before listening to drum beats will shape how babies continue to parse what they are listening to while we record EEG. How do we learn about musical patterns? Haley Kragness, PhD candidate Even if you have never taken any music lessons, chances are that you know when you hear a note in a song (even an unfamiliar song) that is unexpected, or maybe even flat-out wrong. By adulthood, we have become “enculturated” to pitch patterns – through years of listening to the music of our culture, we learn what notes normally come after what other notes. Do children know which notes and chords sound “right,” too? In our lab, we use a musical game to investigate what children know. Three-, 4-, and 7-year-old children were invited to press a computer key repeatedly to move themselves through a piece of music, and we measured how much time they spent on each chord. The 4- and 7-year-olds spent more time on stable chords that could bed a musical phrase than unstable chords, which mirrors adult performance in this same experiment. The 3-year-olds, however, did not differentiate between stable and make good endings to phrases and unstable chords. From this experiment, it appears that knowledge of which chords are stable may develop between 3 and 4 years. How exactly does this knowledge develop, and what happens in the third year of life to facilitate this? These questions will be investigated in future experiments. Do motor and musical timing skills developed together in childhood? Jennifer Chan, BSc; Andrew Chang, PhD candidate Motor Development and Musical Timing Abilities. Time perception is necessary for a multitude of daily activities such as speech, coordination in sports, and listening to music. Prior research suggests that auditory and motor systems of the brain are linked for time processing, for example that listening to the music makes people want to move to the beat. In our study, we aim to understand whether motor and music abilities develop together in childhood. How did we investigate it? What have we found? The present study investigates this issue by comparing auditory time perception abilities and motor timing abilities of children ages 6 and 7. Children completed music listening games on a touch screen in response to different auditory sounds, their auditory time (duration and rhythm) discrimination abilities. Also, we employed child-friendly EEG to measure neural activities generated by the auditory cortex, in response to sound deviation detection. We collaborated with Dr. John Cairney and the INCH lab for this project, and recruited participants who have participated in the CATCH study. So far, more than 80 children have participated in our study (thank you all)! Our results show that auditory time perception is related to motor timing. Children with better motor skills had better timing abilities for sounds than children with poorer motor skills. While this effect was seen in durational timing (e.g., detecting the gap between two sounds, which is related to perceiving speech and music), we did not find a difference in rhythmic abilities in relation to motor abilities. What does this mean? According to our findings, music and motor skills develop together in childhood. The next steps are to research the efficiency of combining music in motor training, to improve motor skills of children with motor function disorders such as Developmental Coordination Disorder (DCD). DCD is a neurodevelopmental disorder affecting fine and gross motor abilities that affects 5-6% of school-aged children. Rhythmic interventions have already been successfully applied to other adult motor deficits such as Parkinson’s disease. Our next step is to develop clinical interventions for children with DCD that can be applied early in development.

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Do babies like songs with steady tempo? Susan Marsh-Rollo, Research Assistant; Takayuki Nakata, PhD As we develop from infancy to adulthood, our preference for sounds changes from simple to more complex ones. For example, parents may say ‘Hi!’ to their babies repeatedly with the pitch of the extending vowel going up and down in a smooth and simple manner. Their parent's infant-directed vocalization are often more rhythmical that in adult-directed speech. Lullabies passed down from generation to generation in different parts of the world also feature such smooth and simple rhythmic patterns. When adults sing alone or sing to other adults, the tempo of the song usually changes, typically speeding up leading to a climax and slowing down at the end of the phrase. One previous study found that mothers sing slowly to their babies with a very stable tempo, presumably to make the song ‘simpler’ for babies perceive and recognize. In our lab, 6- to 7-month-old babies listened to two versions of an unfamiliar lullaby recorded and performed by a professional musician. One version featured a steady tempo whereas in the other version, the tempo changed. Babies were able to listen to the song as long as they liked. We compared how long babies chose to listen to each of the two versions. We learned that babies who had attended music classes tended to prefer a song with a steady tempo rather than a variable tempo. Babies who were not in music classes equally liked both the stable and the variable versions. In sum, we have learned that as infants gain musical experience, they start to prefer music with steady tempo. Can music lessons affect early development? Susan Marsh-Rollo, Research Assistant; Elaine Whiskin, Research Assistant; Sean Hutchins, PhD; Laura Cirelli, PhD In partnership with the Royal Conservatory of Music’s Research Centre, we offered families the opportunity to participate in a project looking at the cognitive benefits of early music education. The RCM has developed a curriculum that consists of fun and engaging music and arts-based activities that are designed to promote cognitive development in infants. More than 30 families participated in this long term study that began when their babies were 9-11 months old. Babies came to visit our Behaviour Lab and to listen to different types of music- one that sounds pleasant to adults (tonal) and the other that sounds unpleasant to adults (atonal). We measured if they had a preference similar to adults. Families were then randomly assigned to attend a 20 week session of free music classes at the Royal Conservatory either immediately or after a second set of tests 20 weeks later. After 20 weeks, we brought everyone back for a second round of testing in the lab. Our young participants when those getting lessons immediate were now between the ages 14-16 months. We again measured their preference of tonal vs atonal music along with EEG measures of their perception of musical beat and meter. Infants who attended the first set of classes were very similar to the infants from the delayed classes group in all measures and tasks with the exception of the EEG test. We found that the infants with parents who were more musically trained had larger beat and metric responses than babies with musically untrained parents. All the families involved in our study reported that their babies loved classes at the RCM and that it was a “very positive experience”!

Once More, With A Different Feeling - Can Children Communicate Different Emotions in Music? Haley Kragness, PhD candidate Imagine yourself as an actor, delivering a line on stage. Your character is happy – how do you say your lines? Now your character is sad. Do you say your lines the same way? You would probably talk more slowly and with a lower pitch in a sad situation. Just as we use different features of our voice to communicate emotions, musicians change the way they play a piece of music to communicate emotions to the audience. We wanted to know whether children understand how these different musical features relate to different emotions. We asked 3-year-old, 5-year-old, and 7-year-old children to come into the lab and play our Lab Piano. The lab piano is special because it is controlled with a series of simple taps – so anyone can play it, even if they’ve never taken any piano lessons! Children were asked to play songs with different emotions, and we measured different aspects of their performance – was it fast or slow? Loud or soft? Did they play short notes or long notes? By 5 years old, children begin to use many of the same features as adults do, suggesting that they understand how different musical aspects are linked to different emotions. How does information flow on the brain when we hear a sound? David Prete, PhD student Many areas of the brain become active when we are listening to sounds such as music or speech. However, we do not have a clear understanding of how these different areas communicate to each other when we are listening to sounds and how actively listening to the sounds might change how the different areas communicate with each other. In order to investigate these questions we measure brain wave activity while people are actively listening to pure tones or while sounds play in the background and people watch a movie. Once we have an understanding of how the different parts of the brain communicate in adults we will look into developmental changes that come from musical training or leaning different languages.

4 Good music, synchronized brains? Hector Orozco, Masters Student Social interaction is essential for human life. Even while engaging in a seemingly trivial interaction, our brains constantly integrate information to meet the coordinative demands of our lives. Previous studies have shown that humans synchronize body rhythms while engaging in social coordination (such as heart rate while singing together in a choir, or body movement while playing in a string quartet…). We are not sure, however, if these synchronization patterns extend to the brain (synchronized brain oscillations), mainly because studying real time brain activity related to social interaction is very complex. We are interested in using music as a context to study the real-time neural dynamics of social interaction. We place multiple sensors on the scalp of high-level pianists while they play piano duos together and then have them rate their performances in terms of synchronicity and quality. We aim to find brain activity linked to social interaction and how it relates to both the musicians’ perception of their interactions and the quality of the music they are producing. This kind of research is important because we are developing and honing advanced analysis techniques that lie in the intersection of social neuroscience and electrical engineering that have direct impact in clinical settings, such as understanding interactions in people with autism, and those with dementia who can no longer communicate verbally.

This study is currently recruiting pianists (8 years of formal training 2+ years of

ensemble playing) To participate or for more information, please

contact orozcoph@mcmaster.ca Coupled body sways, coupled music Andrew Chang, PhD candidate People perform tasks in coordination with others in daily life, but the mechanisms are not well understood. We employed the motion capture system in the LIVELab to record the body motion of the string quartet musicians performing together, to investigate how they achieve interpersonal coordination. Using mathematical models to examine string quartet dynamics, we demonstrated that musicians assigned as leaders affect other performers more than musicians assigned as followers. These effects were present during performance, when musicians could only hear each other, but were magnified when they could also see each other, indicating that both auditory and visual cues affect nonverbal social interactions. Furthermore, the overall degree of coupling between musicians was positively correlated with ratings of performance success. Thus, we have developed a method for measuring nonverbal interaction in complex situations and have shown that interaction dynamics are affected by social relations and perceptual cues. These methods could be applied to study other forms of social interactions, such as baby-mother or patient-therapist interactions. How do our brains track time? Andrew Chang, PhD candidate Everyday communication is highly complicated as we need to capture fleeting information in speech and music in order to understand their messages and quickly coordinate appropriate reactions. I am investigating how brains encode dynamic information in speech and music that unfolds over time. Using non-invasive EEG to record brain waves, I’m studying neural oscillations with specific periodicities (tempos) that reflect activity generated in different brain areas. I hypothesize that the periodicity of brain wave oscillations serves as a pacemaker representing timing regularities in speech and music, and that periodicity preciseness determines the quality of the encoding. My studies showed that the brain wave activities around 20 Hz synchronizes with the tempo of the rhythm we play people. And better temporal synchronization in the brain leads to better perception of the sound. This suggests that our brain waves operate to make us “ready” for perceiving dynamic information in speech or music that unfolds over time. We are now investigating what happens in the brains of people with dyslexia.

5 Understanding anxiety in musical performances. How do you feel when you have to give a speech in front of people? Sarah Lade, PhD student Sweaty palms, fluttering heart? A moderate level of stress in this situation can help you perform at your best. But for some of us, this natural stress response is so intense that it prevents us from giving our best performance. This situation is all too familiar for people with Musical Performance Anxiety (MPA), who experience extreme anxiety when performing in front of an audience. We are interested in looking at four different reactions to performing music in front of an audience: thought patterns, brain activity, physical reactions, and behavioural reactions. In our experiments, we record musicians’ brain and muscle activity while they perform in two different social situations: either with or without an audience. We hope to determine what neural, physical, and cognitive differences exist in performers with MPA and without MPA in order to design effective interventions for anxious musicians in the future. The current study is being run with adults, and we plan to repeat this experiment with both adolescents and children. This study is currently recruiting pianists (RCM Grade 10+) with and without performance anxiety, who perform at

least three times a year. To participate or for more information, please contact: lades@mcmaster.ca or call 905-525-9140 Ext. 24811.

Listening to and moving with a musical beat. Kate Einarson, PhD When we listen to music, we use the timing information (the beat and metre) to help us organize what we hear. The beat of music is the steady underlying pulse that we can tap our foot to. Although almost every kind of music has an underlying beat, there are cultural differences in the way we groups beats together into different metres. European and North American music tends to group beats into simple groups of repeated twos (like a march), threes (like a waltz), or fours. For example, Bon Jovi’s “Hurts So Good” has a typical four-beat grouping. However, in other cultures music is often grouped into fives, sevens, or other complex combinations. For example, Pink Floyd’s “Money” has beats grouped in seven. These complex metres are easy to understand for adults who grow up listening to them, but hard for those who don’t. We investigated whether children are also better at processing music with familiar compared to foreign timing structures. Is some music easier to listen to or move to? We found that five-year-old children were able to notice mistakes in the speed and timing of the musical beats when the music was culturally typical. However, when music had five or seven beat groupings, five-year-olds weren’t able to notice the mistakes anymore. Four-year-olds showed a similar pattern of results, but also found the task more challenging overall. Seven-year-olds performed better overall than the younger children. However, they were still biased, and less good at noticing the mistakes in culturally unfamiliar music. Given the pattern of their listening abilities, we expected that children would also be better at drumming along to music in four, compared to music in five or in seven. However, we found that for all ages, whether or not children were able to match their drumming to music actually depended more on how individual songs sounded than on the timing structure. For example, songs with very strongly accented beats were much easier for children to drum to than songs where the beat was less clear, regardless of how the beats were grouped. Born to perceive rhythm? Elaine Whiskin, Research Assistant; Gábor Háden, PhD The Infant Auditory Lab tested four-month-old infants on the basic abilities necessary to perceive music and specifically, how the brain picks up rhythm. The research seeks to answer whether children at an early developmental stage are able to automatically and passively process sounds that are either accented or not, or if this is a skill that they learn from their surrounding environment over time. The results would be fundamental in understanding the role and impact of rhythmic activities in everyday life, such as language development or following along to the beat of a song. The research is an extension of studies done on newborns at the Institute of Cognitive Neuroscience and Psychology Research Centre for Natural Sciences, Hungarian Academy of Sciences led by our visiting researcher, Gabor Haden, PhD. We are continuing our collaborative research with Gabor after his return to Budapest.

Our new scientific publications 1. Bonin, TL, Trainor, LJ, Belyk, M, and Andrews, PW (2016). The source dilemma hypothesis: Perceptual uncertainty contributes to musical emotion. Cognition 2. Chang, A, Bosnyak, DJ, and Trainor, LJ (2016). Unpredicted pitch modulates beta oscillatory power during rhythmic entrainment to a tone sequence. Frontiers in Psychology 3. Chang, A, Livingstone, SR, Bosnyak, DJ, and Trainor, LJ (2017). Body sway reflects leadership in joint music performance. Proceedings of the National Academy of Sciences 4. Cirelli, LK, Spinelli, C, Nozaradan, S, and Trainor, LJ (2016). Measuring neural entrainment to beat and meter in infants: Effects of Music Background. Frontiers in Neuroscience 5. Cirelli, LK, Wan, SJ, and Trainor, LJ (2016). Social effects of movement synchrony: increased infant helpfulness only transfers to affiliates of synchronously moving partners. Infancy 6. Einarson, KM and Trainor, LJ (2015). The effect of visual information on young children’s perceptual sensitivity to musical beat alignment. Timing and Time Perception 7. Einarson, KM and Trainor, LJ (2016). Hearing the beat: Young children’s perceptual sensitivity to beat alignment varies according to metric structure. Music Perception 8. Kragness, H and Trainor, L (2016). Listeners lengthen phrase boundaries in self-paced music. Journal of Experimental Psychology: Human Perception and Performance 9. Slugocki, C, Bosnyak, D, and Trainor, LJ (2017). Simultaneously-evoked auditory potentials (SEAP): A new method for concurrent measurement of cortical and subcortical auditory-

evoked activity. Hearing Research 10. Smith, NA, Folland, NA, Martinez, DM, and Trainor, LJ (2017). Multisensory object perception in infancy: 4-month-olds perceive a mistuned harmonic as a separate auditory and

visual object. Cognition 11. Trainor, LJ, and Cirelli LK (2015) Rhythm and interpersonal synchrony in early social development. Annals of the New York Academy of Sciences.

Please visit our lab website for more information: https://trainorlab.mcmaster.ca/