Sound Health with Mickey Hart

Research

I am a cognitive neuroscientist with a background in physics developing tools to study dynamic mechanisms of cognition and development. To understand the human brain, I study the cooperation between perceptual and motor systems in shaping our perception of the world. A focus is on the perception and production of temporal rhythms in music and language and potential therapeutic and educational applications of music. Rhythm provides a well-defined test case for the hypothesis that the motor system plays a causal role in auditory perception, and that the development of this system is important for learning to temporally guide attention. I approach research questions using behavior and EEG/MEG recording and analysis, including recordings of the complex auditory brainstem responses (cABR). I am also involved in the development of new algorithms to analyze multimodal EEG/MEG data, including the integration of motion capture data with EEG analysis, and new approaches to connectivity analysis. Below is a video from the INC Open House on 4/2/19, explaining my recent research.


Below are some of my projects (click on title to read more):

2019 National Endowment for the Arts (NEA) Research Lab 


NEAUC San Diego PIs Drs. John Iversen, Tim Brown, and Terry Jernigan, in partnership with San Diego Children’s Choir and Vista Unified School District, will study the potential effects of musical interventions on early childhood development. They will conduct the Early Academic Readiness and Learning Intervention - longitudinal intervention trials of vocal music in pre-school aged children, testing if music has impact on school readiness, cognition, and emotion. Read the press release!

4/1/19 - 3/31/22

Additional Description:

University of California at San Diego - La Jolla, CA - $300,000
The University of California/San Diego, in partnership with San Diego Children’s Choir and Vista Unified School District, will establish a group of studies to trace the potential effects of various musical interventions on early childhood development. The goal is to identify and relate those effects to age, status of brain development, and
genetic variation. Lab activities begin with a feasibility study with Children in Transitional Kindergarten (pre-kindergarten) classes who participate in a daily singing program. The children will be assessed on their cognitive, emotional, social, academic, and music skills. Following the feasibility study, the research will test various hypotheses about musical experiences during childhood. This lab leverages the team's deep experience in music and large-scale longitudinal child development studies, bridging such disparate fields such as cognitive and developmental
psychology, neuroscience, musicology, and education. The lab also will assist the Arts Endowment in pursuing data collection and analysis within the Adolescent Brain Cognitive Development (ABCD) study, of which the agency is a sponsor.


Brain Mechanisms of Rhythm Perception

Testing the Impact of the Motor System on Auditory Perception

06/01/15 – 05/31/19 - National Science Foundation

Funding to develop a network diagram of brain networks involved in auditory temporal processing. Testing the hypothesis that the motor system plays a causal role in perception of auditory rhythms, by providing predictive signals. This will be tested using EEG measurements as well as by causally influencing the network using transcranial magnetic stimulation to test if transient deactivation of motor structures interferes with beat perception and auditory brain dynamics.

Impact of Music training on child brain and behavioral development

I direct the SIMPHONY project, a comprehensive longitudinal study of the impact of music training on child brain and behavioral development. While it is well known that adult musicians’ brains and abilities are different from non-musicians, longitudinal study is necessary to prove that the differences are not pre-existing. The study tests the hypothesis that music training will accelerate brain development. The study is the first of its kind to combine a five-year longitudinal design with a deep battery of brain and behavioral measures. It is made possible by collaborating with NIHfunded longitudinal research at UCSD Center for Human Development which aims to define developmental trajectories for brain growth. I added a musically-enriched subgroup into this study to enable the study of experience on development, as well as several additional tests, including measurements of the complex auditory brainstem response, funded by a REaCh pilot grant. To date, baseline data has been analyzed, showing structure/function links between motor system development and rhythmic skills, and showing how the development of specific brain circuits, not calendar age, is more predictive of performance. A notable finding is that the maturity of the motor system predicts auditory rhythm perception ability. The data are in the process of being thoroughly quality-controlled and reprocessed and funding will be sought to fully analyze it.

  • Iversen, J.R., Baker, J., Smith, D., Jernigan, T. (2016). “SIMPHONY: Studying the impact music practice has on neurodevelopment in youth. Mid-term results.” International Conference on Music Perception and Cognition, San Francisco, July 9.
  • Iversen, J.R., Baker, J., Smith, D., Jernigan, T. (2015). “SIMPHONY: Studying the impact music practice has on neurodevelopment in youth. An update.” Society for Music Perception and Cognition, Nashville, August 4.
  • Iversen, J.R. (2014). "SIMPHONY: Baseline relationships between rhythmic skill and brain structure." Flux Conference. July, Los Angeles, CA.

EEG/MEG signal processing

I have published several novel analysis methodologies for fusing multimodal data and causal connectivity analysis. Leading implementer of MEG methods within EEGLAB. Currently work with Prof. Jorge Cortes of UCSD Mechanical and Aerospace Engineering aims to develop new quantitative formalisms for the analysis of brain networks, drawing on distributed network science and bilinear systems to propose solutions to several problems facing existing methods, including the learning of network structure from
EEG data, and dealing with missing nodes.

  • Courellis, H., Mullen, T., Poizner, H., Cauwenberghs, G., and Iversen, J.R. (2017) EEG-Based Quantification of Dynamic Causal Connectivity Present in Cortical Networks of Subjects Performing BCI Monitored Cognitive Tasks. Frontiers in Neuroscience.
  • Courellis, H.S., Peterson, D., Poizner, H., Cauwenberghs, G., Iversen, J.R. (2015). EEG Based Inference of Causal Cortical Network Dynamics in Reward-Based Decision Making. IEEE Biological Circuits and Systems (BioCAS).
  • Iversen, J.R. & S. Makeig, (2014) “MEG analysis in EEGLAB”, in Supek, S. & Aine, C.J., (eds.), Magnetoencephalography, Berlin: Springer-Verlag, pp 199–212.
  • Iversen, J.R., A. Ojeda, T. Mullen, M. Plank, J. Snider, G. Cauwenberghs, and H. Poizner. (2014). Causal
    analysis of cortical networks involved in reaching to spatial targets. Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE 4399–402.
  • Broccard FD, Mullen T, Chi YM, Peterson D, Iversen JR, Arnold M, Kreutz-Delgado K, Jung TP, Makeig S, Poizner H, Sejnowski T, Cauwenberghs G. (2014). Closed-loop brain-machine-body interfaces for noninvasive rehabilitation of movement disorders. Annals of biomedical engineering. 42(8):1573-93.


Brain Mechanisms of Temporal Perception

Humans have a unique mode of perceiving time by organizing events around a regular succession of beats. Beats are important moments in time most commonly encountered in music, but may also be important for language perception. Because of the links between hearing and moving, study of beat perception gives us a clear window into a fundamental form of sensorimotor integration, and is a rich stage for understanding network interactions among systems in the brain. A central focus of my ongoing work is to understand the brain network dynamics responsible for beat perception using techniques with high temporal resolution, such as magneto- and electroencephalography (MEG & EEG). While we have known from brain imaging that motor structures are active during beat perception, their dynamic role is unknown. Is motor activity merely suppressed movement, or does it play a more constitutive role in auditory perception? To address this quandary, I have developed the ‘beat shift’ paradigm, which has enabled, for the first time, the dissociation of brain activity related to the internally generated pulse from external sound-evoked activity, a critical distinction for understanding auditory and motor contributions that was conflated by past studies. Using this method, I have shown that the internal sense of pulse that we perceive when listening to rhythms modulates auditory responses to sound, as well as for the first time demonstrating that brain activity in premotor cortex dynamically represents the pulse, independent of sound. I pushed the boundaries of data analysis, introducing for the first time in the music cognition field advanced quantitative methods including independent component analysis (ICA) and causal connectivity metrics to begin to describe the dynamic neural circuits underlying rhythm perception. Building on these results, I co-developed the Action Simulation for Auditory Prediction (ASAP) hypothesis, which makes the strong, and novel, claim that the motor system is causally necessary for beat perception. Currently I am leading a project to test the ASAP hypothesis through connectivity measures of EEG and direct tests of the causal role of the motor system in perception using TMS to transiently suppress portions of the motor system in order to observe effects on auditory rhythm perception and activity. This work represents a unique approach within the field, and a new combination of methods to test what is perhaps the most clearly articulated mechanistic hypothesis regarding the interaction of motor and auditory systems during beat perception.

  • Ross JM, Iversen JR, Balasubramaniam R (2018) The Role of Posterior Parietal Cortex in Beat-based Timing Perception: A Continuous Theta Burst Stimulation Study. J Cogn Neurosci 30:634–43.
  • Iversen, J.R. (2016) In the Beginning was the Beat: Evolutionary Origins of Musical Rhythm in Humans. In: Hartenburger, R (ed) Cambridge Companion to Percussion. Cambridge: Cambridge University Press.
  • Ross J.M., Iversen, J.R., Balasubramaniam, R. (2016) Motor simulation theories of musical beat perception. Neurocase, doi:10.1080/13554794.2016.1242756. Patel, A.D. and J.R. Iversen [equal contribution]. (2014). The evolutionary neuroscience of musical beat perception: The Action Simulation for Auditory Prediction (ASAP) hypothesis. Frontiers in Systems Neuroscience 8:57.
  • Iversen, J.R., B.H. Repp, and A.D. Patel (2009). Top-down control of rhythm perception modulates early auditory responses. Ann. NY Acad. Sci. 1169:58-73.

Role of experience and modality in shaping temporal perception

Additional studies using purely behavioral methods to provide strong constraints on theorizing about neural mechanisms. For many years it has been thought that auditory-motor coupling was inherently more temporally precise than the other senses, and better able to drive rhythmic behavior, to the extent that some have argued that synchronization with visual stimuli must occur via internal recoding into auditory representations. My research has successfully challenged these ideas, providing the first evidence of accurate synchronization to visual stimuli.

  • Iversen, J.R., A.D. Patel, B. Nicodemus, K. Emmorey. (2015). Synchronization to auditory and visual rhythms in hearing and deaf individuals. Cognition 134:232-44.
  • Hove, M.J., J.R. Iversen, A. Zhang, and B.H. Repp. (2013). Synchronization with competing visual and auditory rhythms: bouncing ball meets metronome. Psychological Research. 17:388-398.

 

Universality, language, and rhythm

Work done earlier in my career continues to be relevant in the fields of music cognition and language development. Three studies in particular have stimulated extensive continuing research. In 2008, we were the first to show that basic rhythm perception was not universal, as had been thought for the last century, but was influenced by language experience. This bears on a core question of how infants are able to learn the syntactic structure of language from acoustic cues, and has inspired a number of follow-on studies. In 2009 we presented the first evidence that a non-human animal, a sulphur crested cockatoo named Snowball, could synchronize movement with rhythm. This discovery has since been replicated and has inspired an explosion of empirical and theoretical work on synchronization in animals and the evolutionary importance of synchronization. Finally, we developed a test of pure beat perception (the BAT, or beat alignment test) that has become an international standard in the field and is incorporated in multiple music cognition batteries, including a nationwide study with the BBC in the UK, which studied musicality in over 200,000 people.

  • Iversen, J.R., A.D. Patel, and K. Ohgushi (2008). Perception of rhythmic grouping depends on auditory experience. J. Acoust. Soc. Am. 124: 2263-2271.
  • Iversen, J.R., and A.D. Patel (2008). The Beat Alignment Test (BAT): Surveying beat processing abilities in the general population. In: Proceedings of the 10th International Conference on Music Perception & Cognition (ICMPC10), August 2008, Sapporo, Japan.
  • K. Miyazaki et al. (Eds.), Adelaide: Causal Productions. Patel, A.D., and J.R. Iversen (2007) The linguistic benefits of musical abilities. Trends in Cognitive Sciences 11:369-372.
  • Patel, A.D., J.R. Iversen, M.R. Bregman, and I. Schulz (2009). Experimental evidence for synchronization to a musical beat in a nonhuman animal. Current Biology, 19: 827-830. Link to bibliography: http://www.ncbi.nlm.nih.gov/sites/myncbi/1Zgmefky7S0QI/bibliography/46437349/public

Research Support


  • Large-scale nested studies of the impact of music on brain and behavioral development
    NIH 1R01AA028411-01 (Iversen), September 2019 - August 2022

    This research aims to build a new understanding of the role that music plays in the developing brain and behavior, from improving cognition and school performance to leading to positive health outcomes. It leverages several of NIH’s large scale developmental studies, including the Adolescent Brain and Cognitive Development (ABCD) study.


  • Collaborative Research: Brain mechanisms of rhythm perception: Testing the impact of the motor system on auditory perception
    NSF BCS-1460885 (Iversen), Jun 1, 2015 - May 31, 2019

    Funding to develop a network diagram of brain networks involved in auditory temporal processing. Testing the hypothesis that the motor system plays a causal role in perception of auditory rhythms, by providing predictive signals. This will be tested using EEG measurements as well as by causally influencing the network using transcranial magnetic stimulation to test if transient deactivation of motor structures interferes with beat perception and auditory brain dynamics.


  • SL-CN: Group Brain Dynamics in Learning Network
    NSF SMA 1540943 (Iversen), 09/15/15 – 08/31/20

    The goal of this project is to develop and evaluate new techniques for studying the brain using networked EEG headsets in the ecological environment of the classroom.


  • EARLI Fund UCSD Center for Human Development Grant (Brown, Iversen)
    07/01/2017 – 6/30/2020
    Early Academic Readiness and Learning Intervention is a multi-year study of the effects of an intensive early childhood vocal music program on classroom measures of language, cognition, brain activity, and academic achievement in 80 children.

COMPLETED

  • US-German Research Project: Neural Dynamics of the Integration of Egocentric and Allocentric Cues in the Formation of Spatial Maps During Fully-Mobile Human Navigation
    IIS-1516107 (Makeig), 12/01/2015 – 11/30/2018 NSF
    This project collaborates with Professor Klaus Gramann of the Berlin Institute of Technology on Augmented and Virtual Environment Paradigms Involving Spatial Navigation. We will study EEG responses in freely moving participants as they learn novel maze-like environments. Role: Co-I, Research design and EEG analysis.

  • Cortical Network Dynamics Underlying Cognitive Control Deficits in ADHD
    1R21MH105803 (Makeig, Iversen, Loo), 08/01/2015 – 05/31/2018 NIH / NIMH
    The goal of this project is to develop advanced quantitative methods to analyze EEG recordings in order to create a new map between brain and behavioral symptoms. Role: Co-PI responsible for EEG analysis

  • UC MERCI Network for Research on Music Experience and Communication
    CA-15-328736 (Makeig), 01/1/2015 –3/31/2017 UC Office of the President
    Organize a quarterly seminar series, convene a first Organizational Conference and design and execute a pilot multi-campus research project involving a research group of graduate students from multiple campuses to record, analyze and interpret data in identified common core multi-modal, multi-campus brain/mind/brain/body studies. Role: Board Member & Site Lead.

  • Role of Emotion and Choice in learning
    UCSD REaCh LRH Small Grant
    (NIH), 09/01/2013 – 8/31/2014
    Augmenting REaCh LRH measures using the complex auditory brainstem response (cABR) to study the impact of musical experience on the early encoding of sound. Role: PI. The Grammy Foundation (Iversen) 03/01/2013 – 02/28/2015 SIMPHONY Funding for second and third year testing of an important older cohort ofmusic students within our longitudinal study of the impact of music training on child brain and cognitive development. Role: PI

  • SIMPHONY-Studying the Influence Music Practice Has On Neurodevelopment in Youth
    The San Diego Foundation (Iversen), music07/01/2012 – 06/30/2013
    First year funding to begin a five-year longitudinal study of the impact of music training on child development using an extensive annual battery of brain structural imaging and neuropsychological testing. The goal is to understand how musical training may alter developmental trajectories in brain growth and how this may underlie general cognitive development. This grant funds the development and addition of music-specific variables to the ongoing PLING study, and the recruitment of a cohort enriched for music training. Role: PI

    Additional description: How does musical training influence the child's brain and the development of skills like language and attention? The Neurosciences Institute, UC San Diego, and the San Diego Youth Symphony formed a new partnership to address these questions. We recruited children between 5 to 8 years of age who received or plan to receive instrumental/vocal music instruction to participate in the SIMPHONY study. To understand how music affects the structure of the brain, participants were asked to lie still in an MRI scanner for up to one hour while watching a video. To understand how music affects cognition, participants performed simple computerized tasks. These sessions occurred at different points in their music education and were conducted in association with CHD's PLING Study.