Poster A68, Saturday, March 24, 1:30–3:30 pm, Exhibit Hall C
Resting-state hippocampal functional connectivity depends on handedness
John Scofield1, Jeffrey Johnson1; 1University of Missouri
A hippocampal-cortical network of regions, including lateral parietal, medial prefrontal, and posterior cingulate cortices, has been identified across numerous fMRI studies of episodic memory retrieval (recollection) and resting-state functional connectivity. Consistent over many of these studies is the finding that this network exhibits a left-lateralized bias, particularly in posterior parietal regions and lateral prefrontal cortex. Given that these results are predominantly based on samples of right-handed participants, the current study set out to test the hypothesis that handedness contributes to such lateralization. Resting-state fMRI data were obtained from multiple publicly-available projects (the 1000 Functional Connectomes Project and the Autism Brain Imaging Data Exchange) to provide samples of matched left- and right-handed participants that were sufficient in size for between-group analyses. Whole-brain functional connectivity based on hippocampal seeds revealed differential effects in a left-lateralized fronto-parietal network that were stronger for right-handers. By contrast, left-handed subjects exhibited stronger connectivity in bilateral inferotemporal regions. These differences were supported by across-subject multivariate pattern analysis (MVPA) that classified the handedness of subjects at above-chance levels. The findings highlight the notion that handedness is associated with differences in brain function and suggest that lateralization specific to the hippocampal-cortical memory network is attributable in part to these differences.
Topic Area: LONG-TERM MEMORY: Episodic