Speech, Language, and Hearing Sciences
Neural Systems for Language Processing Lab
Christine Weber-Fox, Ph.D., Director
These labs are located on the ground floor of Heavilon Hall and are designed to investigate brain functions related to language processing in children and adults who are normal speakers or communicatively disordered. The lab in G-5 is primarily dedicated to data acquisition and is shared by Dr. Anne Smith and Dr. Christine Weber-Fox's research groups.
The labs are equipped for recording event-related brain potentials (ERPs) that are time-locked to visually or auditorally presented stimuli such as tones, words, or sentences. The system is also designed to record the participants' responses to stimuli to obtain behavioral measures for the processing tasks. The participants are seated comfortably in a sound isolated room. Visual stimuli are delivered on a computer monitor and auditory stimuli are delivered via headphones. During the testing sessions, the participants are fitted with a cap containing 32 electrodes that rest against the scalp. These electrodes allow for the recording of brain activity that is generated by the synchronized activity of populations of neurons. The ERP recordings provide precise temporal information about brain activity as well as the distribution of the activity over the electrode sites. Finally, these labs are equipped for analyzing the ERP and behavioral data with software such as Neuroscan, Matlab, Systat, and SigmaPlot.
One research focus of the lab is to utilize event-related brain potential (ERP) and behavioral measures to characterize the neural subsystems for language processing in children and adults diagnosed with either stuttering or Specific Language Impairment (SLI). Stuttering and SLI fall into distinct, non-overlapping clinical diagnostic categories. However, for each of these disordered classes, impairments in linguistic processing (as well as more generalized processing deficits) have been thought to play a role in the disorder, although in very different ways. In SLI, for example, language processing may play a central role in the development of the disorder. In contrast, linguistic processing deficits in stuttering children have been hypothesized to be sub-clinical (and perhaps normal in some of the children), however, linguistic complexity is thought to interact with their speech production system demands and contribute to disfluencies. The study of these disordered children and typically developing children provide a unique opportunity for comparisons across three developmental profiles. A long-term goal is to determine how language processing differences in these groups may contribute to the development of their functional communication skills. Another focus of the lab is the study of language processing in bilingual speakers. ERP and behavioral measures are utilized to determine cross-linguistic effects and the effects of delays in second-language learning on the organization of functional neural subsystems involved in processing different types of linguistic structures.