Poster C85, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Age-related differences in the functional connectivity of the medial temporal lobe support successful memory encoding
Lingfei Tang1, Andrea Shafer1, Ryan Liddane1, Hager Alkhafaji1, Noa Ofen1; 1Wayne State University
Recent neuroimaging evidence suggests that the functional maturation of the medial temporal lobe (MTL) contributes to age-related improvement in successful memory encoding. In line with resting-state functional MRI studies in adults, limited evidence from such studies in children suggests a differential pattern of functional connectivity between anterior and posterior portions along the long-axis of the MTL. Furthermore, there is a limited evidence for age-related differences in hippocampal functional connectivity that may be relevant to memory functioning in children. Little is known about the age-differences in MTL functional connectivity that directly underlie successful memory formation, and whether the distinction between anterior and posterior portions of the MTL carry significant explanatory value in observed developmental effects. We collected functional MRI data from 97 participants (ages 8-25) while they studied scenes for a later recognition test. Memory-related activation (for subsequently remembered versus forgotten scenes) was assessed in a priori defined regions located along the long-axis of the hippocampus, entorhinal cortex, and parahippocampal cortex. Memory-related activation in anterior and posterior MTL increased with age, but not in the middle portion of the MTL. Using psycho-physiological interaction analyses, we found that anterior MTL regions showed age-related increase in coupling with regions in the occipital and temporal lobe. In contrast, posterior MTL regions showed age-related increase in negative coupling with regions in the default mode network. These findings suggest that the protracted functional maturation along the long-axis in the MTL supports age-related improvement in memory functioning.
Topic Area: LONG-TERM MEMORY: Development & aging