UC Berkeley

Herein I research the role of the basal ganglia and prefrontal cortex in visual working memory and attention by examining patients with focal, unilateral lesions to these brain regions. By combining patient-based behavioral research with scalp electroencephalography (EEG) I study the specific deficits caused by focal frontal brain lesions and explore the effects that such lesions have on diverse cortical network functioning related to working memory and attention. Furthermore, I investigate the role that neuroplasticity plays in compensating for damage to the prefrontal cortex as relates to working memory and attention.

By examining the localization of cognitive functions in the brain and how these seemingly fixed locations may reflect flexible neural networks that can change in response to brain damage, I show how the intact homologous prefrontal cortex compensates for the damaged hemisphere in patients with unilateral prefrontal lesions when these patients are cognitively challenged. I then expand on this notion of cognitive compensation by demonstrating that behavioral performance is reduced when we block the fidelity of visual information transferred from the damaged to the intact hemisphere. Finally, in a methodological analysis of a unique patient cohort, I address the advantages and limitations of scalp EEG.

Defining specific brain regions by function does not necessarily inform us about how cognitive functions arise or change and adapt during development and in response to brain injury or disease. Rather, I argue that we must adopt a dynamic view of cognition wherein cortical regions are but nodes in fluctuating, malleable networks that give rise to the complexities of human behavior.