Ashley Williams

Research Interests

Ashley is interested in understanding the basis of cognitive deficits in individuals with schizophrenia. Currently, she aims to uncover whether contextual long-term deficits in memory may arise from impaired organization of items or events in a particular order of time. To do this, she has analyzed a large fMRI dataset of healthy controls and individuals with schizophrenia (n=89) while they performed a temporal sequence processing task. Behaviorally, she found that individuals with schizophrenia can retrieve well-learned sequences, however not at the same degree as healthy controls, indicating that they do have temporal processing deficits. For neural analyses, Ashley focused on the hippocampus and dorsolateral prefrontal cortex, due to their involvement in episodic memory and temporal processing. In particular, she has utilized representational similarity analyses, which compare patterns of voxel activation. Essentially, if items that share a particular type of information (e.g. position within a sequence) have similar patterns of activation in a region of interest, that region is likely involved in the processing of that type of information. Currently, there is no work in the field of schizophrenia research that involves this type of analysis. Her analyses have revealed that individuals with schizophrenia have deficits in temporal sequence processing, which may be related to dorsolateral prefrontal cortex (DLPFC) dysfunction rather than hippocampal dysfunction. She is currently writing the manuscript related to these findings. This result that temporal sequence memory deficits are due to DLPFC rather than hippocampal dysfunction is highly impactful as much of the research community still believes that episodic memory problems in schizophrenia are primarily due to hippocampal dysfunction