Temporal and spatial selectivity of hippocampal connectivity with sensorimotor cortex during individual finger movements

Cognitive control refers to brain processes involved in regulating behavior according to internal goals or plans. This study examines whether hippocampal connectivity with sensorimotor cortex during paced movements shows a pattern of spatial and temporal selectivity required for cognitive control. Functional magnetic resonance imaging activity was recorded from thirteen right-handed subjects during a paced, non-mnemonic (repetitive tapping) motor task. Direct and inverse connectivity in sensorimotor cortex were examined from psychophysiological interactions (PPI) from hippocampal seed activity during two sets of analyses: the first identified motor interactions relative to rest, whereas the second identified interactions in motor activity between fingers. Finger representations identified in a previous study were used to evaluate patterns of temporal and spatial selectivity in hippocampal connectivity. Changes in the magnitude of connectivity were identified within the sensorimotor representations of the first (index) through third (ring) fingers across time periods when each finger moved; at each finger representation, hippocampal connectivity was greatest when the represented finger was moving, reflecting temporal selectivity for the timing of finger movements. Similarly, the seeds associated with each finger representation differed in their magnitude of connectivity for adjacent finger representations, reflecting spatial selectivity for the moving finger. The patterns of spatial and temporal selectivity of connectivity during volitional movements in this study meets the criteria for cognitive control adapted from oculomotor studies.