Stimulus generalization is a critical mechanism for facilitating behavioral flexibility. Generalization allows the brain to reduce computational demands that would otherwise be necessary to create unique representations for each and every encounter while allowing the ability to deal with the complexity of real-world situations. Stimulus generalization is a fundamental cognitive...
Approximately 80-90% of individuals with Parkinson’s disease (PD) develop motor speech impairments, predominantly in the form of voice dysfunction. It is known that the motor symptoms of PD arise from degeneration of the dopamine producing neurons in the substantia nigra and dysregulation of basal ganglia motor pathways. It is also...
Decision making is an essential and indispensable element in everyday life. It is posited that parallel, distinct systems subserving deliberative, goal-directed control and automatic, habitual control underlie decision making. Computational accounts suggest that model-based and model-free learning strategies give rise to these two systems respectively. The model-based system is a...
The set of experiments described here test the hypothesis that the declarative memory system supported by the medial temporal lobe and habit/procedural memory supported by the basal ganglia are recruited when learning novel category representations. The theory guiding specific hypotheses about these neural systems and their operation in category learning...
Primary progressive aphasia (PPA) is a debilitating neurodegenerative syndrome that principally impairs the cognitive domain of language. Patients demonstrate deficits in a variety of language faculties including object naming (anomia), word finding, single word and sentence reading, speech comprehension, repetition, syntactic processing, and paraphasia. PPA has been associated with selective...