Summary: New research indicates that older adults may compensate for age-related cognitive decline by increasing activity in a specific attention-related brain region, the locus coeruleus (LC). In a recent brain imaging study, older participants displayed stronger LC responses than younger adults when interpreting ambiguous facial expressions.
This elevated LC activity was particularly evident in older individuals who reported higher emotional resilience and overall mental well-being. The results point to adaptive changes in brain networks that help preserve complex social processing and emotional health during aging.
Key Findings:
- LC Activation: Older adults show greater locus coeruleus activity when evaluating facial expressions that are difficult to interpret.
- Adaptive Connectivity: Enhanced connectivity from the LC to prefrontal cortical regions is associated with better emotional resilience in later life.
- Implications for Mental Health: Supporting this circuit could offer a route to strengthen cognitive and emotional regulation in aging populations.
Source: SfN
Background: As people age, declines in processing speed, working memory, and cognitive control can make it harder to read subtle or ambiguous social cues such as mixed emotional expressions. The locus coeruleus, a small brainstem nucleus that supplies norepinephrine throughout the brain, plays a central role in attention, arousal, and adaptive responses to challenging situations. Its widespread cortical connections make it well positioned to influence high-level decision-making and conflict resolution, functions that are often taxed when interpreting ambiguous social signals.
To investigate whether the LC and its cortical projections change with age to support social perception, Maryam Ziaei and colleagues at the Norwegian University of Science and Technology measured brain activity while younger and older adults performed a facial emotion recognition task. Participants viewed faces that ranged from clearly happy or fearful to mixtures that produced intermediate or complete ambiguity.
Using ultra-high-field 7T MRI, the study compared 75 younger adults (aged about 21–29) with 69 older adults (aged about 67–75). Behaviorally, all participants showed slower responses and reduced confidence when categorizing completely ambiguous faces. Older adults, however, tended to label ambiguous faces as happy more often than younger adults did.
Neuroimaging revealed that older adults had greater LC activation when processing fully ambiguous faces compared with younger adults. Moreover, connectivity between the LC and the dorsolateral prefrontal cortex (dlPFC), a region involved in executive control and decision making, was stronger in older participants during ambiguous trials.
Crucially, individual differences mattered: older participants with the strongest LC–dlPFC connectivity scored higher on self-reported measures of mental well-being and on composite measures of emotional resilience. This pattern suggests that recruitment of the LC and its coupling with prefrontal control regions can support both task performance under uncertainty and broader aspects of emotional health in aging.
The authors propose that increased LC engagement and strengthened LC–prefrontal connections represent an adaptive neural strategy that develops with age to help resolve ambiguous social information. Because the LC system influences attention and arousal and interacts with circuits that regulate emotion, targeting this pathway could have potential to improve social cognition and emotional regulation in older adults. Ziaei notes that such approaches might also benefit younger individuals facing difficulties with social processing, including those affected by anxiety or depression.
About this aging and social neuroscience research
Author: SfN Media
Source: SfN
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Image: Image credit to Neuroscience News
Original Research: Closed access. “Age-Related Increase in Locus Coeruleus Activity and Connectivity with Prefrontal Cortex during Ambiguity Processing” by Maryam Ziaei et al., Journal of Neuroscience. DOI: 10.1523/JNEUROSCI.2059-24.2025
Abstract (condensed):
Interpreting ambiguous cues like mixed facial expressions becomes more difficult with age as cognitive resources decline. Adaptive neural mechanisms are therefore essential for preserving social understanding and mental well-being. The locus coeruleus, the brain’s primary source of norepinephrine, regulates attention, arousal, and stress responses and maintains extensive cortical connections that can support adaptive processing.
Using 7T MRI, the study examined LC function in younger and older adults during a face-emotion-recognition task with graded levels of ambiguity. Participants showed longer response times and lower confidence for absolutely ambiguous faces; older adults were more likely than younger adults to interpret ambiguous faces as happy. Neuroimaging showed that older adults exhibit greater LC activity and stronger LC–dlPFC connectivity during complete ambiguity. Stronger connectivity correlated with higher self-reported mental well-being and greater emotional resilience. These findings indicate that heightened LC engagement supports demanding cognitive tasks, while LC–prefrontal coupling contributes to emotional well-being in healthy aging.