Welcome to the Language Processing and Language Development Lab, located in the Department of Psychology at the University of Pennsylvania. Our research group investigates how humans understand, produce, and learn language. The spoken language that you use everyday is highly complex. You likely know tens of thousands of words but also know many detailed grammatical rules about how to combine those words together to form sentences and communicate complex thoughts. Some of the fundamental questions that our group is interested in include:  How do humans so effortlessly interpret utterances in real-time, “on the fly”, as each utterance is being heard? How do young children learn the meanings of words, and interpret syntactic structure? How do the mental demands of language comprehension influence language learning, and possibly shape the languages of the world? And conversely, does the particular language that we speak change how we see and think about the world around us? Much of our work involves behavioral studies with children and adults, in which we record where someone is looking as they hear or produce speech about their surrounding environment. In this way, we can obtain a moment-by-moment record of what the person believes the speech is referring to, and by extension what kind of linguistic knowledge they must be deploying during language use. This work is highly interdisciplinary and makes direct ties to work done in Psychology, Linguistics, and Computer Science.