I use cognitive neuroscience to investigate auditory processing, speech processing, and psycholinguistics, with an emphasis on plasticity in the neural circuits underlying these processes. I use multiple approaches, spanning behavior (overt response, eyetracking), electrophysiology (EEG, ERP, ABR), and neuroimaging (MRI, fMRI, diffusion tensor imaging) to track auditory learning as it shifts from transient changes in listening to more durable changes in brain structure and function. My overarching hypothesis is that isolating the neurocognitive measures by which experience changes auditory and language systems allows development of more efficient remediation paradigms. I employ music to reveal insights into auditory, speech, and language processing, by 1) considering musical training as a model of auditory learning, and 2) considering music as a complex auditory stream that draws on at least some of the same mechanisms as speech.
Rhythm and Temporally Selective Attention
Speech and music are both auditory communication mechanisms that unfold rapidly in time; so rapidly that detailed processing of all information contained within could easily overwhelm our perceptual systems. Selectively attending to more relevant information in a perceptual scene or stream is a demonstrated cognitive mechanism for dealing with this type of overload problem. It has long been known that we are capable of selectively attending to a more relevant location in space (think of the classic "cocktail party problem" described by Cherry, 1953), but recent evidence suggests we can also direct attention to more relevant moments in time.
The cues that direct attention to specific times in speech and music are an active field of study; I am interested in the role that rhythms in speech and music play in guiding attention. My research has focused on using event-related brain potentials (ERPs) to index the temporal distribution of attention during rhythmic listening, and has demonstrated typical ERP indices of greater attention at times of greater rhythmic or metric importance. Music is a very useful tool for this type of research, as it affords a well-defined and easily manipulated rhythmic structure for probing attention. The results of these studies can then serve as a starting point for defining the relationship between attention and the less clearly defined rhythmic structure of speech.
For more details, see the paper titled Musical meter modulates the allocation of attention across time.
Musical Expertise Effects on Language Processing
Musical training has been shown to have a number of effects on the brain structures and functions involved with music perception. If the affected brain regions are also involved in speech perception, we can expect music training to modulate speech perception as well. This type of training transfer effect from music to speech has been reported for several aspects of the speech signal (see Besson, Chobert and Marie, 2011 for a review), including our result that musical training modulates the brain response to syntactic violations in speech. These findings provide further evidence for shared neural systems between speech and music processing, which highlights the possibility for musical training based interventions for disordered speech processing.
For more details, see the paper titled Musical expertise modulates early processing of syntactic violations in language.