Hippocampal Connectivity in Illiterate Adults from Brazil

Background: The role of hippocampal connectivity for good memory performance is well known in persons with high educational level. However, it is understudied the role of hippocampal connectivity in illiterate populations. Objectives: To determine whether the hippocampal connectivity correlate with episodic memory in illiterate adults. Methods: Thirty-nine illiterate adults underwent resting state functional MRI and an episodic memory test (Free and Cued Selective Reminding Test). We correlated the hippocampal connectivity at rest with the free recall scores. Analyzes were corrected for head motion and physiological BOLD signal. Results: Participants were most female (66%) and black (79%) and the mean age was 49 years-old (±13.9). The mean score on free recall was 27.2 (±10.7) out of 48 points. We found a significant correlation between both hippocampi and the posterior cingulate and ventral medial prefrontal cortex. However, we did not find an association between the hippocampal connectivity and the memory scores. Conclusions: The lack of association with memory scores might be associated with low brain reserve in this group of individuals.