Biology subjects

Burman, D. D.

Publications and source records attributed to Burman, D. D..

2 recordsLinked to original sources

bioRxiv2018

Hippocampal connectivity with sensorimotor cortex during volitional finger movements. II. Spatial and temporal selectivity

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.

neuroscience↗

bioRxiv2018

Hippocampal connectivity with sensorimotor cortex during volitional finger movements. I. Laterality and relationship to motor learning.

Hippocampal interactions with the motor system are often assumed to reflect the role of memory in motor learning. Here, we examine hippocampal connectivity with sensorimotor cortex during two tasks requiring paced movements, one with a mnemonic component (sequence learning) and one without (repetitive tapping). Functional magnetic resonance imaging activity was recorded from thirteen right-handed subjects; connectivity was identified from sensorimotor cortex (SMC) correlations with psychophysiological interactions in hippocampal activity between motor and passive visual tasks. Finger movements in both motor tasks anticipated the timing of the metronome, reflecting cognitive control, yet evidence of motor learning was limited to the sequence learning task; nonetheless, hippocampal connectivity was observed during both tasks. Connectivity from corresponding regions in the left and right hippocampus overlapped extensively, with improved sensitivity resulting from their conjunctive (global) analysis. The cortical laterality of SMC connectivity depended both on the hippocampal source and the task.Functionally-defined seeds produced bilateral connectivity within the hand representation, regardless of whether finger movements were uni- or bimanual; these seeds were located midlateral within the hippocampus, whereas structural seeds were located in the posterior hippocampus and produced unilateral connectivity. Results implicate the hippocampus in volitional finger movements even in the absence of motor learning or recall.

neuroscience↗