Nostalgia, the longing for the past, the good old days or memories that can be triggered by a song, a photograph, a movie or a smell, has previously been associated with reduced stress and sadness. Now, a new study led by researchers from the UK and China has concluded that homesickness is capable of relieving pain.
In their study, the scientists monitored brain activity in 34 volunteers (ages 18 to 25) using fMRI scanners. Half were shown popular content from their childhood, and the rest were shown scenes and objects from modern life. What was the impact? Looking at the images was associated with reduced activity in the area of the brain that controls pain. And the more nostalgic the participants perceived the images, the less pain they claimed to feel. Thus, the nostalgic-themed images seemed to relieve participants’ pain somewhat, and the volunteers rated the pain from the heat-stimulating device lower when looking at the nostalgic images.
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A good memory is capable of reducing headache pain by 10%, according to the study
The benefits of memories go beyond what we thought. Neuroscientists have traced the root of this nostalgic benefit to a region of the brain called the thalamus. This large area of gray matter located just above the brainstem is involved in the transmission of information between the body and the outer layer of the brain, the cortex, and is critical to pain modulation in humans.
The team found that people who viewed nostalgic images reported experiencing lower levels of pain than those who were shown images of other kinds. Furthermore, this pain-relieving effect was found to be stronger when participants experienced less intense pain.
“The more nostalgic the participants felt, the less pain they perceived,” writes first author and psychology researcher Ming Zhang.
According to the researchers, the anterior thalamus is responsible for encoding nostalgia in our brain, while the posterior parietal thalamus encodes pain perception; and the activity of the first can inhibit the second. This is what’s at play. The key role of the thalamus as a link in this analgesic effect.
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When the participants looked at images, the strength of nostalgia they experienced was also strongly associated with connectivity between the thalamus and the periaqueductal gray matter (PGPA), an area of gray matter found in the midbrain.
“All of these regions are involved in flashback processing, sense of self, and emotional appraisal,” the researchers write.
The researchers said that these findings point to a “functional link” between nostalgic memories and the part of the brain that processes pain.
“These findings demonstrate the analgesic effect of nostalgia and, more importantly, shed light on its neural mechanism,” the experts conclude.
Referencia: Ming Zhang, Ziyan Yang, Jiahui Zhong, Yuqi Zhang, Xiaomin Lin, Huajian Cai, Yazhuo Kong et al. Thalamocortical mechanisms for nostalgia-induced analgesia Journal of Neuroscience 1 March 2022, JN-RM-2123-21; DOI: https ://doi.org/10.1523/JNEUROSCI.2123-21.202 2
