Files
Abstract
Visual working memory impairments have been consistently found in people with schizophrenia, however, there is no consensus on the neural mechanisms behind these deficits. The current study aims to build a more cohesive conceptualization of the neural correlates of visual working memory impairment in people with schizophrenia (PSZ) by taking advantage of the strengths from different types of recording methodologies. To do this, non-simultaneous EEG and fMRI recordings of neural signatures were performed in a sample of 5 PSZ and 8 healthy controls (HCS) while performing an identical visual working memory visual change-detection task with varying memory load conditions. PSZ and trials with smaller memory loads showed less intense event related desynchronization of the alpha frequency band in the EEG measures and less BOLD activation in the posterior parietal cortex (PPC) and middle occipital gyrus (MOG) during fMRI. However, these differences were not significant. The load dependent modulation of event related desynchronization of the alpha frequency band was negatively related to load dependent BOLD activation for both the PSZ and HCS groups. In other words, neural signal intensity magnitude was related between recording methodologies. Additionally, the mediating role of thalamic connectivity for the EEG and fMRI signal modulation by load was examined. PSZ were found to have higher task connectivity between the posterior thalamus and PPC and MOG while HCS were found to have higher resting-state connectivity. No mediating role was found for thalamic connectivity on modulation of event related desynchronization of the alpha frequency band and BOLD activation in the PPC or MOG.