Medical Bulletin 14/ November/ 2024 - Video

People in their late teens experience an increased sensitivity to threats after just a few hours left in a room on their own – an effect that endures even if they are interacting online with friends and family. This is according to the latest findings from a cognitive neuroscience experiment conducted at the University of Cambridge, which saw 40 young people aged 16-19 undergo testing before and after several hours alone – both with and without their smartphones. The findings are published in the journal Royal Society Open Science.

Many countries have declared an epidemic of loneliness. The researchers set out to “induce” loneliness in teenagers and study the effects through a series of tests, from a Pavlovian task to electrodes that measure sweat.

The key highlights of the study are:

Scientists detect a heightened “threat vigilance” reaction in adolescents after a few hours of isolation, which socialising online doesn’t appear to ameliorate.

They say the findings might shed light on the link between loneliness and mental health conditions such as anxiety disorders, which are on the rise in young people.

Experiment is the first to find an increased threat response triggered by isolation in humans.

Participants were given initial tests and questionnaires to establish a “baseline”. These included the Pavlovian threat test, in which they were shown a series of shapes on a screen, one of which was paired with a harsh noise played through headphones, so the shape became associated with a feeling of apprehension.

Electrodes attached to fingers monitored “electrodermal activity” – a physiological marker of stress – throughout this test. Each participant returned for two separate stints of around four hours isolated in a room in Cambridge University’s Psychology Department, after which the tests were completed again. There was around a month, on average, between sessions.

All participants underwent two isolation sessions. One was spent with a few puzzles to pass the time, but no connection to the outside world. For the other, participants were allowed smartphones and given wi-fi codes, as well as music and novels. The only major rule in both sessions was they had to stay awake.

However, participants found the threat cue – the shape paired with a jarring sound – more anxiety-inducing and unpleasant after both isolation sessions, with electrodes also measuring elevated stress activity.

On average across the study, threat responses were 70% higher after the isolation sessions compared to the baseline, regardless of whether participants had been interacting digitally.

Reference: Towner, E., Thomas, K., Tomova, L., & Blakemore, S. J. Increased Threat Learning After Social Isolation in Human Adolescents.

Exercise has been shown to improve brain health and reduce the risk of cognitive decline and dementia over the long-term. But engaging in everyday physical activity has immediate benefits for brain health, according to a new study from researchers in the Penn State College of Medicine. The findings were published in the journal Annals of Behavioral Medicine.

The team found that middle-aged people who participated in everyday movement showed improvement in cognitive processing speed equivalent to being four years younger, regardless of whether the activity was lower intensity, like walking the dog or doing household chores, or higher intensity, like jogging. The research team leveraged smartphone technology to interact with participants multiple times during their regular daily lives using a protocol called ecological momentary assessment. Over the course of nine days, participants checked in six times a day, approximately every 3.5 hours.

During each check-in, participants reported if they had been physically active since their last check-in. If they were active, they were asked to rate the intensity of their activity — light, moderate or vigorous. The team analyzed data from 204 participants who were recruited for the Multicultural Healthy Diet Study to Reduce Cognitive Decline & Alzheimer’s Risk. Data was collected during the study’s baseline period. Participants were between the ages of 40 and 65 and residents of the Bronx, NY who had no history of cognitive impairment. Half of the participants were Black or African American and 34% were Hispanic.

The team found that when participants reported being physically active sometime in the previous 3.5 hours, they showed improvements in processing speed equivalent to being four years younger. While there were no observed improvements in working memory, the response time during the working memory task mirrored the improvements observed for processing speed.

Additionally, people who reported being active more often experienced greater short-term benefits compared to those who reported less physical activity overall.

Reference: Jonathan G Hakun, Lizbeth Benson, Tian Qiu, Daniel B Elbich, Mindy Katz, Pamela A Shaw, Martin J Sliwinski, Yasmin Mossavar-Rahmani, Cognitive Health Benefits of Everyday Physical Activity in a Diverse Sample of Middle-Aged Adults, Annals of Behavioral Medicine, 2024;, kaae059, https://doi.org/10.1093/abm/kaae059

A recent study published in the journal Scientific Reports correlates higher levels of pollutant particulate matter to higher occurrences of head and neck aerodigestive cancer.

The article, "Air Pollution Exposure and Head and Neck Cancer Incidence," is the work of a multi-institutional collaboration with researchers from Wayne State University, Johns Hopkins University and Mass General Brigham.

“These findings shed light on the significant role of environmental pollution in cancers of the upper aerodigestive tract, highlighting the need for further awareness, research and mitigation efforts.” said senior author Stella Lee, M.D., of the Center for Surgery and Public Health and Division of Otolaryngology-Head & Neck Surgery at Brigham and Women’s Hospital, a founding member of the Mass General Brigham health care system

The researchers used data from the U.S. Surveillance Epidemiology and End Results (SEER) national cancer database from the years 2002-12. They observed the highest association between this type of pollution exposure with head and neck cancer after a five-year lag period. They focused on PM2.5, which is particulate matter measuring less than 2.5 microns, and its effect on head and neck aerodigestive cancer incidence.

“We are looking at a certain size of air pollution particulates,” said Cramer, Ph.D., associate professor of otolaryngology. “The size of the particles is relevant because the classic model for studying the upper airways is that the nose and throat act as filters before it gets into the lungs. Larger particles are being filtered out, but we are conceptualizing that different types of pollution hit different parts of the airways.”

Reference: Peleman, J., Ruan, M., Dey, T. et al. Air pollution exposure and head and neck cancer incidence. Sci Rep 14, 26998 (2024). https://doi.org/10.1038/s41598-024-73756-3