The arousal-biased competition model predicts that arousal increases the gain on neural competition between stimuli representations. Thus, the model predicts that arousal simultaneously enhances processing of salient stimuli and impairs processing of relatively less-salient stimuli. We tested this model with a simple dot-probe task. On each trial, participants were simultaneously exposed to one face image as a salient cue stimulus and one place image as a non-salient stimulus. A border around the face cue location further increased its bottom-up saliency. Before these visual stimuli were shown, one of two tones played: one that predicted a shock (increasing arousal) or one that did not. An arousal-by-saliency interaction in category-specific brain regions (fusiform face area for salient faces and parahippocampal place area for non-salient places) indicated that brain activation associated with processing the salient stimulus was enhanced under arousal whereas activation associated with processing the non-salient stimulus was suppressed under arousal. This is the first functional magnetic resonance imaging study to demonstrate that arousal can enhance information processing for prioritized stimuli while simultaneously impairing processing of non-prioritized stimuli. Thus, it goes beyond previous research to show that arousal does not uniformly enhance perceptual processing, but instead does so selectively in ways that optimizes attention to highly salient stimuli.

No abstract

The locus coeruleus (LC) plays a critical role in regulating attention via the release of norepinephrine (NE), with levels of tonic LC activity constraining the intensity of phasic LC responses. However, the effects of manipulating tonic LC-NE activity on phasic activity have yet to be demonstrated in humans. In the current fMRI study, we used isometric handgrip to modulate tonic LC-NE activity in the time period immediately afterwards. 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 contrast from a neuromelanin-sensitive structural scan. Thus, LC structural integrity was related to LC functional dynamics and attentional performance during the oddball task. We also found that handgrip led to larger phasic pupil responses to oddball sounds, faster oddball detection speed, and greater frontoparietal network activation, suggesting that something that induces strong LC activity benefits attentional performance for at least the next few minutes. 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. Highlights• We examined how handgrip affects arousal-attention dynamics during an oddball task • Salient stimuli enhanced pupil dilation and were detected faster post-handgrip • A decrease in tonic pupil size after handgrip suggests norepinephrine depletion • MRI-assessed LC integrity was related to oddball detection and pupil dilation • LC integrity also associated with LC-frontoparietal network functional connectivity

These data provide novel insight that among Latinos in primary care, emotion dysregulation is a possible mechanism underlying the indirect relationship between negative affectivity and problematic alcohol use and symptoms of dependence. Results also highlight specific facets of emotion dysregulation as potential targets of intervention. Future research should be longitudinal in nature, be conducted among more representative samples, and utilize measures that will better assess the potential variability in these associations. Results of such work may inform the development of alcohol treatment interventions incorporating the use of adaptive emotion regulation among Latinos in primary care.

Different emotion regulation strategies are distinctly represented in the brains of younger adults. Decreasing a reaction to a negative situation by reinterpreting it (reappraisal) relies on cognitive control regions in the prefrontal cortex, while distracting away from a stressor involves more posterior medial structures. In this study, we used Multi-Voxel pattern analyses (MVPA) to examine whether reappraisal and distraction strategies have distinct representations in the older adult brain, or whether emotion regulation strategies become more dedifferentiated in later life. MVPA better differentiated the two emotion regulation strategies for younger adults than for older adults, and revealed the greatest age-related differences in differentiation in the posterior medial cortex (PMC). Univariate analyses revealed equal PMC recruitment across strategies for older adults, but greater activity during distraction than reappraisal for younger adults. The PMC is central to self-focused processing, and thus our findings are consistent with the possibility that focusing on the self may be a default mechanism across emotion regulation strategies for older people.