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Daniel M. Merfeld is an American neuroengineer, neuroscientist, academic, author, and inventor. He is a professor of Otolaryngology at The Ohio State University, and serves as Senior Vestibular Scientist at the Naval Aerospace Medical Research Laboratory, which is part of the Naval Medical Research Unit Dayton.

Conducting both fundamental and translational research in the field of the vestibular system and balance, Merfeld is best known as an inventor of vestibular implants, and the 2014 recipient of Vestibular Disorders Association (VEDA) Champion of Vestibular Medicine Award in 2014. He is a co-author of the textbook Sensation and Perception.

Merfeld was named a Fellow of the American Institute for Medical and Biological Engineering in 2012, and a Senior Member of the Institute for Electrical and Electronics Engineering (IEEE) in 2012.

Early life

Merfeld grew up in Bloomington, Wisconsin – a rural village in southwest Wisconsin – and attended Bloomington High School.

Education

Merfeld obtained a bachelor's degree in Mechanical Engineering from the University of Wisconsin-Madison in 1982. He then pursued a master's degree in Mechanical and Aerospace Engineering at Princeton University, which he completed in 1985 and went on to receive a Ph.D. in Biomedical Engineering from MIT in 1990, where he also received postdoctoral training in 1990.

Career

Merfeld began his career as a research scientist at MIT from 1991 to 1995. He joined the R.S. Dow Neurological Sciences Institute, as an Assistant Scientist in 1995, advancing to Associate Scientist in 1998. During this time, he joined the Oregon Health and Science University (OHSU) faculty, first as an Adjunct Professor in 1995 and later as a faculty member in 1996 where he contributed to different programs including integrative Biomedical Science and Neuroscience graduate programs until 1999. In 1999, he became an associate professor of Otology and Laryngology at Harvard Medical School and was appointed as Professor in 2012, which he remained until 2017. During the same period, he joined MIT as a faculty member from 2000 to 2017. He has been a professor of otolaryngology in The Ohio State University since 2017, where he also holds courtesy faculty appointments in other programs including Biomedical Engineering, Health and Rehabilitation Sciences, and Speech and Hearing Sciences.

From 1992 to 1995, Merfeld served as an Acting Principal Investigator, leading a team of neurovestibular scientists for the Spacelab Life Sciences - 2 project. Subsequently, from 1996 to 1998, he held the role of Public Relations Director at the Neurological Sciences Institute. In addition, he has organized significant events, including the Vestibular Oriented Research meeting that he founded and helped organize in 2019, 2020 (canceled due to COVID-19), 2021 and 2023.

Research

Merfeld's research in the field of neuroscience focuses on vestibular function, especially its impact on human balance, spatial disorientation, and motion perception. Among his work, he showed that internal models affect translation perception and that rotational cues from vision impact both perception and reflexes. He also discovered that separate neural mechanisms can contribute to vestibular perception and action and worked on providing new diagnostics and treatments for patients suffering from vestibular disorders.

Vestibular function

Merfeld's research has contributed to the understanding of vestibular function. His early research centered on deciphering the brain's processing of ambiguous sensory information, focusing on the interpretation and processing of signals from the otolith organs. Both modeling and experimental work conducted during this research revealed that the nervous system utilizes rotational signals from the canals to maintain awareness of the relative orientation of gravity through the use of internal models. Furthermore, the research demonstrated that these internal models impact the perception of translation and established that rotational cues provided through vision, such as optokinetic cues, influence both translational reflexes and perception. He also found that perceptual sensitivity to motion increases at frequencies below 0.2 Hz, levels off at 0.5 Hz and above, and showed no impact from velocity storage on perception.

Merfeld and collaborators invented, developed, and tested a sensory-replacement vestibular implant for severe peripheral vestibular dysfunction. These studies demonstrated the brain's ability to acclimate to the constant presence of electrical stimulation while simultaneously demonstrating that compensatory vestibulo-ocular responses to modulations of the electrical stimulation could be maintained for months after stimulation onset. Both findings are essential to the success of long-term sensory replacement. He also identified the need for more research in motion sensors, information transfer, training for vestibular-deficient individuals, and prosthetic device effectiveness assessment.

Spatial orientation and sensory processing

Merfeld explored factors influencing the processing of sensory information and how these factors can lead to spatial disorientation. He contributed to a study demonstrating stochastic resonance in muscle spindles by showing that muscle spindle responses could be enhanced when small vibrations were applied. Having showed that internal models influence translation perception, he discovered that the nervous system can generate estimates of linear acceleration in the absence of actual linear acceleration, indicating the existence of internal models aiding sensory information processing related to motion. Additionally, he revealed the brain's utilization of internal models to estimate both simple and complex motion paradigms, offering insights into neural strategies for perceiving motion amidst uncertain sensory data.

In a study published in the Journal of Vestibular Research, Merfeld and colleagues developed the "sensory conflict" model to understand spatial orientation processing. The model successfully predicted aspects of how the brain processes sensory information from the vestibular system. He also worked on a sensory weighting model, and showed that the model successfully simulated sensory processing, eye movements, and perceptual responses in various motion scenarios, offering insights into multisensory motion estimation.

Psychophysical analysis methods

Merfeld has also contributed to the development of new approaches and methods to analyze psychophysical data. His contribution in this area began with a theoretic analysis of the threshold model often assumed to underlie the calculation of thresholds for binary (e.g., left vs right) data acquired using forced-choice direction discrimination paradigms. He and his colleagues built on this framework to show how to fit threshold data across experimental conditions to deliver better threshold parameter estimates and to develop a new method that removes a bias known to impact threshold estimates when data are acquired using standard staircase procedures.

Merfeld and colleagues later developed a method that uses confidence probability ratings – an element of meta-cognition that reflects self-assessment of the conviction in a decision – to reduce the number of trials required to obtain reliable threshold parameter estimates as well as a method to find and remove individual trials that reflect when a subject has a lapse in attention.

Motion perception and balance

Merfeld's research has also explored vestibular perception and its association with motion. His lab tested more than 100 individuals across various ages, discovering perceptual thresholds for motion perception increased after 40, especially for earth-vertical translations. He and his colleagues found that vestibular migraine patients exhibited abnormal sensitivity to specific types of motion, specifically roll tilt, suggesting sensitization of canal-otolith integration, and also suggested that this heightened sensitivity to roll tilt in vestibular migraine patients implied canal-otolith integration sensitization.

Merfeld has studied the impact of vestibular and non-vestibular cues' on perceptual self-motion thresholds. He found that without vestibular function, tilt, translation, and rotation thresholds increased significantly, highlighting the vestibular system's role in self-motion perception. He also examined vestibular thresholds, age, and balance performance, revealing moderate correlations, underlining the importance of vestibular cues to balance even in healthy individuals.

Awards and honors

• 2012 – Fellow, American Institute of Medical and Biological Engineering (AIMBE)
• 2014 – Champion of Vestibular Medicine, Vestibular Disorders Association
• 2023 – Member, NIH/NIDCD Advisory Council
• 2024 – Member, NIH BRAIN Multi-Council Working Group

Selected patents

• US Patent # 6,546,291 – Merfeld, D, Rauch, S, Wall, C, and Weinberg, M (2003). Balance Prosthesis
• US Patent # 7,454,246 – Merfeld, D (2008). Sensor Signal Alignment
• US Patent # 7,933,654 – Merfeld, D, Gong, Rauch, Wall (2011). Vestibular Stimulator
• US Patent # 9,681,835 – Karmali, Haburcakova, Merfeld, D. (2017) Detection of Vestibular Disorders Based on Vestibular Noise
• US Patent # 9,795,335 – Merfeld, D, Chaudhuri, Lim, Priesol, Lewis, & Karmali (2017) Data collection for vestibulogram construction
• US Patent #10,222,444 – Merfeld, D & Ackerman (2019) Systems and methods for moving magnetic resonance imaging

Bibliography

Books

• Sensation and Perception (2008) ISBN 9780878939381

Selected articles

• Merfeld, D. M., Young, L. R., Oman, C. M., & Shelhamert, M. J. (1993). A multidimensional model of the effect of gravity on the spatial orientation of the monkey. Journal of Vestibular Research, 3(2), 141–161.
• Cordo, P., Inglis, J. T., Verschueren, S., Collins, J. J., Merfeld, D. M., Rosenblum, S., ... & Moss, F. (1996). Noise in human muscle spindles. Nature, 383(6603), 769–770.
• Merfeld, D. M., Zupan, L., & Peterka, R. J. (1999). Humans use internal models to estimate gravity and linear acceleration. Nature, 398(6728), 615–618.
• Merfeld, D. M., & Zupan, L. H. (2002). Neural processing of gravitoinertial cues in humans. III. Modeling tilt and translation responses. Journal of neurophysiology, 87(2), 819–833.
• Zupan, L. H., Merfeld, D. M., & Darlot, C. (2002). Using sensory weighting to model the influence of canal, otolith and visual cues on spatial orientation and eye movements. Biological cybernetics, 86(3), 209–230.
• Merfeld, D. M., Park, S., Gianna-Poulin, C., Black, F. O., & Wood, S. (2005). Vestibular perception and action employ qualitatively different mechanisms. I. Frequency response of VOR and perceptual responses during translation and tilt. Journal of neurophysiology, 94(1), 186–198.
• Kobel, M. J., Wagner, A. R., & Merfeld, D. M. (2023). Evaluating vestibular contributions to rotation and tilt perception. Experimental Brain Research, 1–13.

References

1. ^ "Daniel Merfeld, PhD | Ohio State College of Medicine". medicine.osu.edu.
2. "Reducing Risk through Research: NAMRU-Dayton Addresses Spatial Disorientation". DVIDS.
3. ^ "Champions of Vestibular Medicine Help Reduce Diagnosis Times for Patients with Inner Ear Balance Disorders. - Free Online Library". www.thefreelibrary.com.
4. "APA PsycNet". psycnet.apa.org.
5. ^ "Dan Merfeld, Ph.D COF-1537 - AIMBE".
6. ^ "Harvard Otolaryngology" (PDF).
7. "Merfeld, Daniel Michael, 1985 - Finding Aids". findingaids.princeton.edu.
8. "Human Systems Laboratory".
9. "Experiments Focus on Human Balance". Massachusetts Institute of Technology. October 6, 1993.
10. "Biographies of Astronaut and Cosmonaut Candidates: Daniel Merfeld". www.spacefacts.de.
11. "Brain Resolves Sensory Contradictions by Creating its Own Reality". OHSU News.
12. Young, Laurence R.; Oman, Charles M.; Merfeld, Daniel; Watt, Douglas; Roy, Serge; DeLuca, Carlo; Balkwill, David; Christie, Jock; Groleau, Nicolas; Jackson, D. Keoki; Law, Glenn; Modestino, Sherry; Mayer, William (January 1, 1993). "Spatial Orientation and Posture During and Following Weightlessness: Human Experiments on Spacelab Life Sciences 1". Journal of Vestibular Research. 3 (3): 231–239. doi:10.3233/VES-1993-3304. PMID 8275259. S2CID 13361811 – via content.iospress.com.
13. Merfeld, Daniel. "Vestibular Oriented Research Meetings" – via grantome.com. {{cite journal}}: Cite journal requires |journal= (help)
14. "Daniel Merfeld". scholar.google.com.
15. Merfeld, Daniel M.; Park, Sukyung; Gianna-Poulin, Claire; Black, F. Owen; Wood, Scott (July 22, 2005). "Vestibular Perception and Action Employ Qualitatively Different Mechanisms. I. Frequency Response of VOR and Perceptual Responses During Translation and Tilt". Journal of Neurophysiology. 94 (1): 186–198. doi:10.1152/jn.00904.2004. PMID 15728767 – via CrossRef.
16. Grabherr, Luzia; Nicoucar, Keyvan; Mast, Fred W.; Merfeld, Daniel M. (April 1, 2008). "Vestibular thresholds for yaw rotation about an earth-vertical axis as a function of frequency". Experimental Brain Research. 186 (4): 677–681. doi:10.1007/s00221-008-1350-8. PMID 18350283. S2CID 23828694 – via Springer Link.
17. Merfeld, Daniel M.; Haburcakova, Csilla; Gong, Wangsong; Lewis, Richard F. (June 22, 2007). "Chronic Vestibulo-Ocular Reflexes Evoked by a Vestibular Prosthesis". IEEE Transactions on Biomedical Engineering. 54 (6): 1005–1015. doi:10.1109/TBME.2007.891943. PMID 17554820. S2CID 27513413 – via IEEE Xplore.
18. Wall III, C.; Merfeld, D. M.; Rauch, S. D.; Black, F. O. (January 1, 2003). "Vestibular prostheses: The engineering and biomedical issues". Journal of Vestibular Research. 12 (2–3): 95–113. doi:10.3233/VES-2003-122-305. PMID 12867668. S2CID 239106329 – via content.iospress.com.
19. Cordo, Paul; Inglis, J. Timothy; Verschueren, Sabine; Collins, James J.; Merfeld, Daniel M.; Rosenblum, Stuart; Buckley, Scott; Moss, Frank (October 22, 1996). "Noise in human muscle spindles". Nature. 383 (6603): 769–770. Bibcode:1996Natur.383..769C. doi:10.1038/383769a0. PMID 8892999. S2CID 4236452 – via www.nature.com.
20. Merfeld, Daniel M.; Zupan, Lionel; Peterka, Robert J. (April 22, 1999). "Humans use internal models to estimate gravity and linear acceleration". Nature. 398 (6728): 615–618. Bibcode:1999Natur.398..615M. doi:10.1038/19303. PMID 10217143. S2CID 204992501 – via www.nature.com.
21. Merfeld, D. M.; Zupan, L. H. (February 1, 2002). "Neural Processing of Gravitoinertial Cues in Humans. III. Modeling Tilt and Translation Responses". Journal of Neurophysiology. 87 (2): 819–833. doi:10.1152/jn.00485.2001. PMID 11826049 – via CrossRef.
22. Merfeld, Daniel M.; Young, Laurence R.; Oman, Charles M.; Shelhamert, Mark J. (January 1, 1993). "A Multidimensional Model of the Effect of Gravity on the Spatial Orientation of the Monkey". Journal of Vestibular Research. 3 (2): 141–161. doi:10.3233/VES-1993-3204. PMID 8275250. S2CID 9429082 – via content.iospress.com.
23. Zupan, L. H.; Merfeld, D. M.; Darlot, C. (March 1, 2002). "Using sensory weighting to model the influence of canal, otolith and visual cues on spatial orientation and eye movements". Biological Cybernetics. 86 (3): 209–230. doi:10.1007/s00422-001-0290-1. PMID 12068787. S2CID 5674795 – via Springer Link.
24. Merfeld, Daniel M. (May 1, 2011). "Signal detection theory and vestibular thresholds: I. Basic theory and practical considerations". Experimental Brain Research. 210 (3): 389–405. doi:10.1007/s00221-011-2557-7. PMC 3096492. PMID 21359662 – via Springer Link.
25. Lim, Koeun; Merfeld, Daniel M. (October 1, 2012). "Signal detection theory and vestibular perception: II. Fitting perceptual thresholds as a function of frequency". Experimental Brain Research. 222 (3): 303–320. doi:10.1007/s00221-012-3217-2. PMC 4105942. PMID 22923225 – via Springer Link.
26. Chaudhuri, Shomesh E.; Merfeld, Daniel M. (March 1, 2013). "Signal detection theory and vestibular perception: III. Estimating unbiased fit parameters for psychometric functions". Experimental Brain Research. 225 (1): 133–146. doi:10.1007/s00221-012-3354-7. PMC 3570703. PMID 23250442 – via Springer Link.
27. Leek, Marjorie R.; Hanna, Thomas E.; Marshall, Lynne (May 1, 1992). "Estimation of psychometric functions from adaptive tracking procedures". Perception & Psychophysics. 51 (3): 247–256. doi:10.3758/BF03212251. PMID 1561050. S2CID 16318969 – via Springer Link.
28. Yi, Yongwoo; Merfeld, Daniel M. (April 1, 2016). "A quantitative confidence signal detection model: 1. Fitting psychometric functions". Journal of Neurophysiology. 115 (4): 1932–1945. doi:10.1152/jn.00318.2015. PMC 4869509. PMID 26763777.
29. Clark, Torin K.; Merfeld, Daniel M. (October 1, 2021). "Statistical approaches to identifying lapses in psychometric response data". Psychonomic Bulletin & Review. 28 (5): 1433–1457. doi:10.3758/s13423-021-01876-2. PMID 33825094. S2CID 233174528 – via Springer Link.
30. Bermúdez Rey, María Carolina; Clark, Torin K.; Wang, Wei; Leeder, Tania; Bian, Yong; Merfeld, Daniel M. (September 22, 2016). "Vestibular Perceptual Thresholds Increase above the Age of 40". Frontiers in Neurology. 7: 162. doi:10.3389/fneur.2016.00162. PMC 5046616. PMID 27752252.
31. King, Susan; Priesol, Adrian J.; Davidi, Shmuel E.; Merfeld, Daniel M.; Ehtemam, Farzad; Lewis, Richard F. (October 4, 2019). "Self-motion perception is sensitized in vestibular migraine: pathophysiologic and clinical implications". Scientific Reports. 9 (1): 14323. Bibcode:2019NatSR...914323K. doi:10.1038/s41598-019-50803-y. PMC 6778132. PMID 31586151.
32. Kobel, Megan J.; Wagner, Andrew R.; Merfeld, Daniel M. (July 1, 2023). "Evaluating vestibular contributions to rotation and tilt perception". Experimental Brain Research. 241 (7): 1873–1885. doi:10.1007/s00221-023-06650-5. PMC 11161027. PMID 37310477. S2CID 259148698 – via Springer Link.
33. Karmali, Faisal; Bermúdez Rey, María Carolina; Clark, Torin K.; Wang, Wei; Merfeld, Daniel M. (September 22, 2017). "Multivariate Analyses of Balance Test Performance, Vestibular Thresholds, and Age". Frontiers in Neurology. 8: 578. doi:10.3389/fneur.2017.00578. PMC 5682300. PMID 29167656.

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