Sara Guediche
EMAIL: sag25@pitt.eduI am a graduate student in the Center for Neuroscience at the University of Pittsburgh. My research examines the neural basis of verbal working memory and language processes using behavioral and functional neuroimaging techniques. I am interested in the neural representations that underlie verbal working memory and language and to what extent they overlap and interact with one another.
In the verbal working memory domain, we conducted a study that examined the impact of two different within-list similarity manipulations on immediate serial recall performance. We contrasted, the effect of similarity at the level of articulatory features versus phoneme similarity and evaluated performance differences as a function of the item’s serial position. Using functional magnetic resonance imaging, we also examined the modulation of BOLD response in specific brain regions to a manipulation of phonological similarity and investigated whether the observed changes in activity were specific to the modality of stimulus presentation (acoustic vs. visual), in a manner that is consistent with existing theoretical models.
In more recent work, we are probing the nature of the verbal representations maintained in memory by comparing serial recall performance between speech and Morse code in fluent Morse code users. Due to the inherent differences in the acoustic properties of speech and Morse code, we attempt to dissociate between verbal working memory processes that are specific to speech input versus verbal working memory processes that rely on acoustic-specific or higher-level abstract phonological representations.
My dissertation work builds upon these ideas by investigating how speech-based representations are adapted. Using fMRI, we will investigate the underlying neural mechanisms that contribute to perceptual adaptation of frequency-distorted speech. Due to the fact that the cerebellum plays a key role in perceptual adaptation of visuomotor distortions, we will examine its potential involvement in the domain of speech perception. Changes in activity that are observed within specific subregions of the cerebellum and their relationship to changes in activity in cerebral cortex may also enable us to make predictions about functional connectivity providing some clues for the general role of the cerebellum in cognitive processes.