Abstract Individuals with Alzheimer’s disease (AD) often experience semantic processing problems, which are often manifested as difficulties in naming objects during language. Our current knowledge about the neural bases of semantic processing problems in AD is limited and is mainly focused on the anterior temporal region hub-and-spoke model, which is derived from other disease states such as semantic primary progressive aphasia. Nonetheless, the modern dual stream theory of language processing suggests that speech functions can be dissociated into a dorsal stream of brain structures that support phonological mapping, and a ventral stream of brain regions beyond the anterior temporal region that support semantic associations. AD is commonly associated with ventral stream damage but semantic deficits in AD have not been thoroughly examined from the perspective of the dual stream theory of language processing. Moreover, semantic processing can be further subdivided into contextual information (thematic knowledge) and categorical associations (taxonomic knowledge), which dissociate into different portions of the ventral stream outside the anterior temporal region. Interestingly, individuals with post-stroke aphasia demonstrate the same types of semantic association problems as AD and the essential anatomy of semantic processing in aphasia remains unclear. The PI is currently supported by a NIDCD R01 (DC014021) to study the sub-networks that support semantic processing in language in post-stroke aphasia. This supplement seeks to expand this research into AD to directly leverage the existing research on post-stroke aphasia and yield clinically relevant knowledge on AD. We will test the hypothesis of the neuroanatomical dissociation between thematic and taxonomic processing in AD in comparison with post-stroke aphasia. This AD project will have a synergistic relationship with the existing post-stroke aphasia project. It will be within the scope of the current project and it will also directly focus on a significant clinical problem in AD and stimulate additional research in progress in AD. Through a comparative analysis between AD and post-stroke aphasia, we will assess shared and core aspects of the neurobiology of semantic associations. It will also evaluate AD specific aspects of semantic processing problems, which may lead to individualized interventions.