Isometric exercise facilitates attention to salient events in women via the noradrenergic system Abstract   The locus coeruleus (LC) regulates attention via the release of norepinephrine (NE), with levels of tonic LC activity constraining the intensity of phasic LC responses. In the current fMRI study, we used isometric handgrip to modulate tonic LCNE activity in older women and in young women with different hormone statuses during the time period immediately after the handgrip. During this posthandgrip time, an oddball detection task was used to probe how changes in tonic arousal influenced functional coordination between the LC and a right frontoparietal network that supports attentional selectivity. As expected, the frontoparietal network responded more to infrequent target and novel sounds than to frequent sounds. Across participants, greater LCfrontoparietal functional connectivity, pupil dilation, and faster oddball detection were all positively associated with LC MRI structural contrast from a neuromelaninsensitive scan. Thus, LC structure was related to LC functional dynamics and attentional performance during the oddball task. We also found that handgrip influenced pupil and attentional processing during a subsequent oddball task. Handgrip decreased subsequent tonic pupil size, increased phasic pupil responses to oddball sounds, speeded oddball detection speed, and increased frontoparietal network activation, suggesting that inducing strong LC activity benefits attentional performance in the next few minutes, potentially due to reduced tonic LC activity. In addition, older women showed a similar benefit of handgrip on frontoparietal network activation as younger women, despite showing lower frontoparietal network activation overall. Together these findings suggest that a simple exercise may improve selective attention in healthy aging, at least for several minutes afterwards.

Early attentional processes distinguish selective from global motor inhibitory control: an electrical neuroimaging study The rapid stopping of specific parts of movements is frequently required in daily life. Yet, whether selective inhibitory control of movements is mediated by a specific neural pathway or by the combination between a global stopping of all ongoing motor activity followed by the reinitiation of taskrelevant movements remains unclear. To address this question, we analyzed electrical neuroimaging responses to global vs selective inhibition stimuli presented during a GoNoGo task. Participants had to respond as fast as possible with their two hands to Go stimuli and to withhold the response from the two hands (global inhibition conditions, GNG) or from only one hand (selective inhibition, SNG) when specific NoGo stimuli were presented. Behaviorally, we replicated previous evidence for slower response times in the SNG than in the Go condition. Electrophysiologically, there were two distinct phases of eventrelated potentials modulations between the GNG and the SNG conditions. At 110150ms poststimulus onset, there was a difference in the strength of the electric field without concomitant topographic modulation, indicating the differential engagement of statistically indistinguishable configurations of neural generators for selective and global inhibitory control. At 150200ms, there was a change in the electric field topography, indicating the engagement of distinct configurations of neural generators. Source estimations localized these effects within bilateral temporooccipital and posterior parietal regions and within a parietocentral network, respectively. Our results suggest that while both types of motor inhibitory control depend on global stopping mechanisms, selective and global inhibition still differ quantitatively at early attentionrelated processing phases.