UPFRONT | News and events AGING Older people have become younger The functional ability of older people is nowadays better when it is compared to that of people at the same age three decades ago. This was ob-served in a study conducted at the Faculty of Sport and Health Sciences at the Uni-versity of Jyväskylä, Finland. The study compared the physical and cognitive perfor-mance of people nowadays between the ages of 75 and 80 with that of the same-aged people in the 1990s. “Performance-based meas-urements describe how older people manage in their daily life, and at the same time, the measurements reflect one’s functional age,” says the prin-cipal investigator of the study, Professor Taina Rantanen. Among men and women between the ages of 75 and 80, muscle strength, walking speed, reaction speed, verbal fluency, reasoning and work-ing memory are nowadays significantly better than they were in people at the same age born earlier. In lung function tests, however, differences between cohorts were not observed. “Higher physical activity and increased body size ex-plained the better walking speed and muscle strength among the later-born cohort,” says doctoral student Kaisa Koivunen, “whereas the most important underlying factor behind the cohort differences in cognitive performance was longer education.” Postdoctoral researcher Matti Munukka continues: “The cohort of 75-and 80-year-olds born later has grown up and lived in a differ-ent world than did their coun-terparts born three decades ago. There have been many favourable changes. These include better nutrition and hygiene, improvements in health care and the school system, better accessibility to education and improved working life.” The results suggest that increased life expectancy is accompanied by an in-creased number of years lived with good functional ability in later life. The ob-servation can be explained by slower rate-of-change with increasing age, a higher lifetime maximum in physi-cal performance, or a com-bination of the two. “This research is unique because there are only a few studies in the world that have compared perfor-mance-based maximum measures between people of the same age in different historical times,” says Ran-tanen. “The results suggest that our understanding of older age is old-fashioned. From an aging researcher’s point of view, more years are added to midlife, and not so much to the utmost end of life. Increased life expec-tancy provides us with more non-disabled years, but at the same time, the last years of life comes at higher and higher ages, increasing the need for care. Among the ageing population, two si-multaneous changes are happening: continuation of healthy years to higher ages and an increased number of very old people who need external care.” —UNIVERSITY OF JYVÄSKYLÄ -JYVÄSKY-LÄN YLIOPISTO NEUROBIOLOGY To keep pain in check, count down Is the heat still bearable, or should I take my hand off the hotplate? Before the brain can react appropri-ately to pain, it must evaluate and integrate sensory, cognitive and emotional factors that modulate the perception and processing of the sensation itself. This task re-quires the exchange of information between different regions of the brain. New studies have confirmed that there is a link between the subjective experience of pain and the relative levels of neural activity in functional structures in various sectors of the brain. However, these investigations have been carried out primarily in contexts in which the perception of pain was intensi-fied either by emotional factors or by consciously focusing attention on the painful stimulus. Now, LMU neuroscientist Enrico Schulz, in collaboration with colleagues at the University of Oxford, has asked how cognitive strategies that affect one’s subjective perception of pain influ-ence the patterns of neural activity in the brain. In the study, 20 experimental subjects were exposed to a painful cold stimulus. They were asked to adopt one of three approaches to attenuating the pain: (a) counting down from 1000 in steps of 7, (b) thinking of something pleasant or beautiful, and (c) persuading themselves --by means of auto-suggestion --that the stimulus was not really that bad. During the ex-perimental sessions, the subjects were hooked up to a 7T magnetic resonance imaging (MRI) scanner to visualise the patterns of neural activity in the brain, which were later analysed in detail. In order to assess the efficacy of the different coping strategies, participants were also asked to evaluate the subjective intensity of the pain on a scale of 0 to 100. The results revealed that the count-down strategy was the most effective of the three methods. “This task obviously requires such a high level of concentra-tion that it distracts the subject’s attention significantly from the sensation of pain. In fact some of our subjects managed to reduce the perceived intensity of pain by 50%,” says Schulz. In a previous paper published in the journal Cortex in 2019, the same team had already shown that all three strategies help to attenuate the perception of pain, and that each strategy evoked a different pattern of neural activ-ity. In the new study, Schulz and his collaborators carried out a more detailed analysis of the MRI scans, for which they divided the brain into 360 regions. The attenuation of pain is clearly a highly complex process, which requires a cooperative re-sponse that involves many re-gions distributed throughout the brain. Analysis of the response to the countdown technique re-vealed close coordination be-tween different parts of the insu-lar cortex, among other patterns. The imaginal distraction method, i.e. calling something pictur-esque or otherwise pleasing to mind, works only when it evokes intensive flows of information between the frontal lobes. Since these structures are known to be important control centres in the brain, the authors believe that engagement of the imaginative faculty may require a greater degree of control, because the brain needs to search through more ‘compartments’ --to find the right memory traces, for in-stance. Comparatively speaking, counting backwards stepwise --even in such awkward steps --is likely to be a more highly con-strained task. —Materials pro-vided by Ludwig-Maximilians-Universität München. www.Cndoctor.ca 6 Chiropractic and Naturopathic Doctor October 2020
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