I am an Assistant Professor at the Leiden Institute of Advanced Computer Science (LIACS) and a visiting scholar at the University of California, San Diego in the Center for Research in Language (CRL). I conduct research at the intersection of language, cultural evolution and computation. On this page you will find information about me, my research interests and my contact information.
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This project focuses on the interaction between common knowledge and learning in creating symbolic representations for tools in gesture and sign. Systematic preferences have been found for the use of different strategies for naming man-made hand-held tools. People tend to either show how you hold it or show what it looks like. Sign languages differ in the relative frequencies of use of these strategies and variations in the choice of strategy seem to be conditioned by meaning and context. With the use of online crowdsourcing platforms we rapidly map out initial biases people may have and through laboratory artificial language learning experiments we investigate how these biases interact with pressures from human learning.
The goal of this project is to develop novel methods for analyzing video and depth data capturing human (communicative) behavior. I conducted a first experiment in this domain with Savi Namboodiripad, Ryan Lepic (Linguistics) and Dan Lenzen (Cognitive Science), where we measured changes in gesture as a result of the process of conventionalization with Microsoft Kinect, while participants played a charades-like guessing game. Currently, I am also working with Nuno Vasconcelos, head of the Statistical Visual Computing Laboratory (SVCL) on machine learning methods for the analysis of sign language data. We are collecting a large video data set of ASL sentences and are using Deep Learning for continuous sign language translation directly from video.
This collaboration studies the emergence of language about time. With Tyler Marghetis (Indiana University) and Esther Walker (UCSD), I designed and implemented experiments in which participants were asked to communicate about concepts of time with a novel, spatial signaling device. Processes like social coordination and transmission resulted in the emergence of patterns. While many results in the field of language evolution suggest that language adapts to the brain, the brain responses of participants in these kinds of experiments has, to the best of our knowledge, never been directly measured. Therefore we are now working with Seana Coulson, head of the Brain and Cognition Lab (BCL) at UCSD, to investigate the impact of initial bias and social convention on brain responses with EEG.
I have always loved making things and besides getting creative with different kinds of arts and crafts I get very excited about DIY electronics projects. As a master's student in Artificial Intelligence I collaborated with a few classmates to build an autonomous robotic blimp, named Zeppy. The project was financially supported by the University of Groningen and the result was rewarded with study credits. The university used our robot for promotional activities and special events. Currently at UCSD I am working with Eric Leonardis (Cognitive Science) on a dancing robot, bringing life and bounciness into a crocheted purple penguin bird.
I love designing outreach projects to bring scientific experiments and lectures to non-academic communities. In the Netherlands, over the years this grew into a collaborative experiment/exhibit with Mark Dingemanse and Sean Roberts from the Max Planck Institute in Nijmegen. By creating interactive interfaces, we collect real data with event visitors as participants, and these events rapidly yield publishable results. In San Diego I became a member of BrainScratch, a collective of thinkers, makers, artists and communicators who have a passion for making science accessible to the bigger public through artistic and immersive experiences, installations and presentations related to complex systems science.
My PhD research was on the emergence of structure in speech. I worked with computer models to run language evolution simulations and I developed innovative experimental methods for studying the evolution of combinatorial structure with human participants. In my experiments, people learned and produced artificial languages that were produced with a slide whistle. One of the main aims was to investigate to what extent structures in sound systems for speech can be explained as the result of general cognitive biases and the process of cultural transmission.
Namboodiripad, S., Lenzen, D., Lepic, R. & Verhoef, T. (2016) Measuring conventionalization in the manual modality. The Journal of Language Evolution 1(2), 109-118.
Verhoef, T., Walker, E. & Marghetis, T. (2016) Cognitive biases and social coordination in the emergence of temporal language. Proceedings of the 38th Annual Conference of the Cognitive Science Society. (pp. 2615-2620) Austin,TX: Cognitive Science Society.
Verhoef, T., Padden, C. & Kirby, S. (2016) Iconicity, Naturalness and Systematicity in the Emergence of Sign Language Structure. The Evolution of Language: Proceedings of the 11th International Conference (EVOLANG11)
Verhoef, T., Kirby, S. & de Boer, B. (2015) Iconicity and the Emergence of Combinatorial Structure in Language. Cognitive Science. pp. 1–26.
Verhoef, T., Roberts, S. G. & Dingemanse, M. (2015) Emergence of systematic iconicity: Transmission, interaction and analogy. Proceedings of the 37th Annual Conference of the Cognitive Science Society. (pp. 2481-2486) Austin,TX: Cognitive Science Society.
Verhoef, T., Kirby, S. & de Boer, B. (2014) Emergence of combinatorial structure and economy through iterated learning with continuous acoustic signals. Journal of Phonetics 43C, pp. 57-68
Verhoef, T. & de Boer, B. (2014) Iterated learning of sound systems and the emergence of tone categories. In The evolution of language: Proceedings of the 10th international conference (evolangX). (pp. 545-546). Hackensack NJ: World Scientific.
Verhoef, T. (2014) Cultural evolution, compression and the brain. In The Past, Present and Future of Language Evolution Research (pp. 22-30).
Verhoef, T. (2013) Efficient coding in speech sounds: Cultural evolution and the emergence of structure in artificial languages. PhD Thesis, University of Amsterdam
Verhoef, T. , Kirby, S. & de Boer, B. (2013) Combinatorial structure and iconicity in artificial whistled languages. In M. Knauff, M. Pauen, N. Sebanz, & I. Wachsmuth (Eds.), Proceedings of the 35th Annual Conference of the Cognitive Science Society (pp. 3669-3674) Austin, TX: Cognitive Science Society.
Verhoef, T. (2012) The origins of duality of patterning in artificial whistled languages. Language and Cognition 4(4), 357-380.
Verhoef, T., de Boer, B., & Kirby, S. (2012) Holistic or synthetic protolanguage: Evidence from iterated learning of whistled signals. In The evolution of language: Proceedings of the 8th international conference (evolang8). (pp. 386-375). Hackensack NJ: World Scientific.
de Boer, B. & Verhoef, T. (2012) Language Dynamics in Structured Form and Meaning Spaces, Advances in Complex Systems 15(3),1150021-1–1150021-20
Verhoef, T., Kirby, S. & Padden, C. (2011) Cultural emergence of combinatorial structure in an artificial whistled language. In L. Carlson, C. Hölscher & T. Shipley (Eds.), Proceedings of the 33rd Annual Conference of the Cognitive Science Society (pp. 483-488). Austin, TX: Cognitive Science Society.
Verhoef, T. & de Boer, B.G. (2011) Cultural emergence of feature economy in an artificial whistled language. In E. Zee & W. Lee (Eds.), Proceedings of the 17th International Congress of Phonetic Sciences (pp. 2066-2069). Hong Kong: City University of Hong Kong.
Verhoef, T. & Boer, B.G. de (2011). Language acquisition age effects and their role in the preservation and change of communication systems. Linguistics in Amsterdam, 4(1), 1-23.
Verhoef, T. & de Boer, B. (2010) The critical period and preservation of emerged vowel systems, In: Smith, A. D. M., Schouwstra, M., de Boer, B. & Smith, K. (Eds.) The Evolution of Language, Proceedings of the 8th International Conference (evolang8) (pp. 509–510 ) New Jersey: World Scientific