EEG Lab

What is EEG?

EEG stands for electroencephalography.  We place electrodes on the scalp to record electrical activity in the brain.  It’s totally safe and non-invasive!  The electrodes don’t actually touch the scalp–there is a conductive gel in-between.  The voltage of the electrical signals is tiny; we use an amplifier to record them.   Here is a quick video introduction to EEG.  In our lab, we use two kinds of data from EEG. One is event-related potentials (ERPs), which are brain responses to specific events (like a sound) within a few milliseconds.  We also use neural oscillations, which are patterns of brain activity at different frequencies, occurring over a period of a few seconds, or even longer.

EEG Research on Sentence Processing

Soyeon Chun is leading our project to investigate neural oscillations that are generated while people are listening to, and preparing to recall, a list of words.  Sometimes the words form a sentence, and sometimes they are in a scrambled order.   In addition, sometimes the words are presented with background noise.  We are starting this line of research with adults who do not have a history of language problems, and who speak only one language.  As we build on this work, we plan to include bilingual speakers, adults with a history of language difficulties, and children with and without language disorders.  Our long-term goal is to have better tools for assessing language disorders in diverse populations.

ERP Research on Auditory Processing

Auditory processing disorder and its relation to language disorder has a complex and controversial history.  It is very unclear to what extent auditory processing disorder, language impairment, and dyslexia are co-morbid or reflect different aspects of the same underlying deficits.  Differential diagnosis is challenging and sometimes contentious.  I have used behavioral instruments to investigate the role of auditory processing in language development.  I demonstrated that current diagnostic methods do not distinguish between SLI and auditory processing disorder, and that there may not be two distinct clinical entities.  I hypothesize that auditory processing influences language development, but also that language knowledge and ability in turn influence auditory processing.  I believe that behavioral methods must be complemented by electrophysiological methods in order to make progress in this complex problem space.  I have collected pilot data using ERPs.  Participants listen and respond to sounds, and take brief tests of written and spoken language.  We examine how brain activity in response to the sounds is related to the results of these tests.