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As people get older, they tend to have lower levels of anxiety. But why? A new brain imaging study has found that older individuals are faster at recognizing and responding to negative emotions. The findings, published NeuroImage, go against the idea that older adults are less engaged with negative emotions due to cognitive decline or that they are better at regulating negative emotions. Instead, the results suggest that older adults may develop a more automatic way of processing negative emotions.
The study aimed to investigate the relationship between aging, trait anxiety, and changes in cognitive and affective functions. The researchers were motivated by previous findings that older adults tend to have lower susceptibility to anxiety disorders compared to younger and middle-aged adults. However, it was not clear how age-related changes in anxiety symptoms, such as worry and somatic symptoms, were related to changes in cognitive and affective processes.
“We are interested in emotion dysfunction in early dementia, including those people with subjective complaints of memory problem and mild cognitive impairment,” said study author Chiang-shan Ray Li, a professor of psychiatry and neuroscience at Yale University School of Medicine.
“The extant studies of dementia focus on cognitive dysfunction, although evidence suggests that emotional problems, including apathy, are at least equally prominent early during the course of dementia. To help this research, we thought it is important to understand the mechanisms of emotional processing during healthy aging.”
The researchers were particularly interested in testing two hypotheses of diminished anxiety in aging. The cognitive control hypothesis (CCH) suggests that older adults regulate negative emotions more effectively, leading to a greater focus on positive information. The dynamic integration theory (DIT), on the other hand, suggests that age-related cognitive decline and neural degradation result in a relative difficulty in processing negative emotions, forcing older adults to focus on positive information.
For their study, the researchers recruited a sample of 88 healthy adults aged 21 to 85 years from the greater New Haven, Connecticut area who were physically healthy with no major medical conditions. They were assessed using the State-Trait Anxiety Inventory to measure trait anxiety.
During the study, brain images were collected using a 3-Tesla MRI scanner. The researchers used a widely used paradigm called the Hariri task, which required participants to match emotional faces with the same emotional expression as the target face. This task reliably engages brain regions involved in emotion processing, such as the amygdala and the saliency circuit. The researchers analyzed the brain activation patterns during the task to investigate age-related changes in emotion processing.
The researchers found that older adults had lower levels of anxiety and were faster at identifying negative emotional faces compared to neutral faces. This relationship was specific to negative emotions and was not seen with positive emotions. Older adults were able to respond quickly without sacrificing accuracy, suggesting that age-related cognitive declines did not play a role.
“The finding of a negative correlation of age with reaction time in identifying negative vs. neutral emotional faces was a surprise to us,” Li told PsyPost. “Most studies of the same or similar behavioral tasks did not report reaction time data, and we thought that was because there wasn’t anything significant to report.”
A region of the brain called the dorsal and rostral anterior cingulate cortex (dACC/rACC), which is involved in processing emotions, showed reduced activation in older adults when identifying negative emotional faces. This suggests that negative emotions are less salient or important to older adults compared to younger adults.
Interestingly, the researchers observed that as age increased, there was a stronger connection between the dACC/rACC and another brain network called the default mode network. This increased connectivity was associated with faster response times in identifying negative emotional faces.
“Older people experience less anxiety, a finding that we replicated in the study,” Li told PsyPost. “The psychological and neural mechanisms of age-related reduction in anxiety are far from clear, however. Our findings do not support the hypothesis of better or more efficient cognitive control in older people or the hypothesis of age-related deficits in registering negative facial emotions.”
“Instead, the findings showed that older relative to younger people are faster in matching negative emotional faces, and we speculate that perhaps this happens via an automatic process such that negative emotions do not easily ‘surface’ to awareness and cause anxiety.”
In other words, the findings suggest that as people age, they become more automatic in processing negative emotional information. They can quickly recognize and respond to negative emotions without much effort. This is in contrast to other cognitive abilities that may decline with age. But the study authors said that further research is needed to explore the physiological markers and brain mechanisms underlying these age-related changes in emotional processing.
“Automaticity seems something intuitive, but it remains unclear exactly what it means,” Li noted. “What happens to the info of negative emotional faces after it is ‘automatically’ processed? Will the information be available to impact other cognitive and affective processes? Will the finding extend to studies of non-facial emotional stimuli? Likewise, although we have some evidence from brain imaging to support automaticity, much remains to be understood of the neural bases of this interesting age-related observation.”
“The study was supported by the National Institute of Aging,” the researcher added.
The study, “Age-related reduction in trait anxiety: behavioral and neural evidence of automaticity in negative facial emotion processing“, was authored by Shefali Chaudhary, Sheng Zhang, Simon Zhornitsky, Yu Chen, Herta H. Chao, and Chiang-Shan R. Li.
