How learning ability changes with age
Anna Kalinina, PCR.news
Half a century ago, people, as a rule, studied at school or university, and devoted the rest of their lives to work. Today, the education we receive in our youth is no longer enough — in order to remain competitive, we need to know more and constantly update our skills. Together with Kata Academy, we tell you why it becomes more difficult to learn new things with age and how studying helps to delay the unpleasant effects of aging.
Among 2,752 people surveyed by Pew Research in 2016, 73 percent of people over the age of 18 called themselves "eternal students." All of them have taken courses or attended master classes in the last 12 months (at the time of the survey), while only 36 percent have studied the skills they need in the profession.
Continuing education, that is, mastering new knowledge throughout life, has several key advantages: people learn to cope with a rapidly changing world, can claim higher wages, and, as 80 percent of respondents noted, constantly enrich their lives with something new and interesting.
The authors of the survey estimated that 81 percent of people in the age group from 18 to 29 years old continued their education, and 76 percent aged 30 to 49 years old. This level was also maintained among the surveyed people aged 50-64 years — 72 percent, while 62 percent of people over 65 years of age continued to study. Although the survey results show that with age fewer and fewer people are engaged in self-education in one form or another, even among the elderly, those who have not stopped mastering new knowledge predominate.
Old age is not a joy
The older a person is, the more difficult it is for him to master new information. Scientists note that after 50 years, the most important cognitive processes deteriorate: memorization of information, its translation into long-term memory, reaction speed, the ability to reason and think logically. The reason is how the plasticity of the brain changes — the ability to build, rebuild and restore connections between nerve cells — neurons. The signal from neuron to neuron is transmitted along the processes, between which there is a tiny distance — the synapse.
Neuroplasticity of the brain is assessed by the number of active synapses. It is believed that the greater the volume and thickness of the cerebral cortex, the more synapses, more branched dendrites and long axons of neurons. Scientists have learned to measure the volume and thickness of the cortex, to assess the complexity of the structure of the brain using magnetic resonance imaging (MRI). In a study involving 563 people aged 20 to 86 years, they found that the total volume of the brain and the thickness of the cortex decrease with age. It is these changes that explain cognitive impairments in the elderly. However, by changing the volume of the brain, we can only indirectly talk about neuroplasticity, since the brain consists of many cells.
Fortunately, science allows us to more accurately estimate the number of neural connections. Scientists can calculate how many molecules of synaptophysin, which is contained in the neurotransmitter bubbles of almost all presynaptic neurons, and thus estimate how many synapses are located in a specific area of the brain. One such study showed that during the aging of macaques, the concentration of synaptophysin decreases, which means that the number of neural connections in the brain decreases.
But it's not just the number of neurons that matters, but also how active they are. With the help of functional MRI, scientists can also determine which areas of the brain are activated at rest, during mental or physical exertion, and how their activity changes during aging. It turned out that the neural activity of the frontal lobe increases with age. This directly affects the thought processes associated with planning, concentration and memorization of instructions, that is, it allows us to cope with various tasks.
Now neuroscientists can even influence the activity of certain synapses and see how this affects the ability to learn. On the postsynaptic membrane there are receptors for glutamate — NMDA receptors. When activated, they can modulate the strength of signal transmission: weaken some synapses, and strengthen some. Moreover, the result of this modulation depends on the frequency at which signals are initially sent from one neuron to another. Such modulation is necessary because if synapses are allowed to increase indefinitely in strength, they will reach the maximum level of efficiency, and it will be impossible to encode new or "update" outdated information.
Like any receptor, NMDA can be activated or inhibited (that is, its activity can be increased) by substances, in this case structurally similar to glutamate. Studies have shown that in young animals, high-frequency activation of these receptors increases the signal strength, which contributes to the translation of new information into the "storage" of long-term memory. However, in order to obtain the same result in elderly animals, it is necessary to increase the frequency of signaling or the time of stimulation. In other words, the older the organism, the more difficult it is to fundamentally assimilate new information.
In another study, rats were trained to find a hidden platform in a pool of water. When the animals coped with this task and got to the surface, scientists gave them NMDA receptor inhibitors in small and large doses. Then the experiment was repeated. Young and middle—aged rats found it easier to find a platform with small doses of the inhibitor, and vice versa with large doses. In older animals, where memory impairment was already normally observed compared to younger individuals, a small dose of the NMDA inhibitor reduced the effectiveness of the task. In other words, they were more susceptible to disruption of the function of NMDA receptors.
In human studies, memory and learning ability were also impaired when taking NMDA inhibitors. Thus, by acting on NMDA receptors associated with learning, it is possible to influence the plasticity of the brain.
No longer children
One of the most plastic areas of the brain is the prefrontal cortex. This is the area of the frontal lobe of the brain where human individuality is stored — what psychologists call higher-order cognitive processes and executive functions. Simply put, these are things like reasoning, self-control and attention.
The human brain. The prefrontal cortex area is highlighted in color.
Thanks to functional MRI, we know that in adolescents and adults, the prefrontal cortex areas related to executive functions differ significantly. The fact is that the prefrontal cortex of the human brain develops gradually. This explains why children tend to be more impulsive, restless and have difficulty concentrating. Nevertheless, it is the "undeveloped" prefrontal cortex that helps them learn a foreign language more easily than adults.
The color shows areas that differ in adolescents and adults.
According to one classification, human memory can be divided into two systems:
declarative, responsible for memorizing information and facts that can be formulated and explained;
non—declarative, responsible for the acquisition of skills, unconscious or hidden knowledge, reactions and habits - for example, the ability to play the piano or dance.
Areas of non-declarative memory develop early, while declarative memory works better in adults who have a developed prefrontal cortex. Activation of declarative memory can suppress non-declarative memory, and vice versa. When learning new things, adults rely on the prefrontal cortex and learn rules and grammar better than children. Thus, at the first stage of learning a new language, adults cope better, while children begin to achieve success later. Studies also show that adults learn better when the prefrontal cortex is "turned off" by cognitive exhaustion, which occurs after performing a difficult task or stimulating the prefrontal cortex with magnetic pulses of a certain frequency.
Of course, when learning new things in everyday life, no one specifically "turns off" the prefrontal cortex. The ability to learn is a trainable skill: the more a person devotes himself to learning new things, the easier it is for him. Although adults and the elderly need more time to study, but at the same time, the accuracy of tasks remains at the same level as that of young people. The ability to generalize information, that is, to include new data in the existing picture of the world, in adults over 45 years old remains at the same level as in people aged 60-90 years. This means that with proper perseverance, you can learn new things at any age.
In addition, many different approaches and strategies have been developed for adult psychology education.
As a rule, inductive methods are used in teaching children (that is, they follow from the particular to the general), and for adults, on the contrary, deductive methods are characteristic. In other words, an adult is first told the rule, and then demonstrated how it is applied in various situations. With a child, they act differently: first they show examples, from which they then deduce a general rule.
Unlike children, adults have developed internal motivation. They do not need a significant figure of a teacher — just a mentor (mentor) who tells them how to act in a difficult situation and regularly gives feedback. They can also actively participate in the organization of the learning process. That is why electronic educational platforms are so popular now, which allow you to independently create a schedule and track progress. In addition, it is important for adults to put their new skills into practice, so their training is often associated with solving real problems. Sometimes they also add to this the execution of tasks in a group designed to simulate a workflow.
Studying without stopping
Mastering new practical skills is not the only reason to continue learning all your life. In a study on rats, it was shown that the study of a new induces trophic activity that is important for healthy brain aging, namely, an increase in the level of brain neurotrophic factor (BDNF). It is of interest to scientists because it has long been associated with cognitive functions such as learning and memory. Like any molecule in the body, BDNF has its own receptor on the postsynaptic membrane.
Interestingly, the activation of the BDNF receptor depends on the activation of NMDA receptors, which, as we remember, are extremely important for the modulation of neuroplasticity. After half an hour of training, the BDNF receptor was activated in the hippocampus of the rat brain. At the same time, if before the experiment, scientists gave rats an NMDA receptor inhibitor, activation of the BDNF receptor did not occur, and if the hippocampus was stimulated with magnetic pulses that mimicked learning, activation of the BDNF receptor increased.
Learning is able to activate NMDA receptors and increase their number, and the more such receptors on the postsynaptic membrane, the slower their function will be impaired with age and the longer the ability to learn will be preserved. Although much is not yet known in this area, glutamate receptors undoubtedly play a key role in the deterioration of memory and learning ability. And prolonged training can increase their activation, improve brain neuroplasticity and slow down cognitive impairments associated with aging.
Another confirmation that plasticity improves during training, scientists obtained by measuring the volume of the brain: monkeys needed 6-20 days of continuous training to increase the volume of gray matter corresponding to the task of the brain area, and people — from three months to a year.
Cognitive load at any age — for example, learning a second foreign language — improves neuroplasticity, which positively affects the switching of attention and the functioning of working memory, as well as increases functional connectivity. All together, this helps to reduce the risk of dementia in old age.
Although in such studies it is most often about learning a new language, it is important to note that any cognitive load has a similar effect for a long time. This was shown by a study conducted on a sample of almost 2,000 people. In those who were engaged in self-education after the age of 50, brain disorders appeared about 8.7 years later than in people who studied intensively in their youth, but then practically did not pay attention to it.
Lifelong learning develops brain flexibility by improving neuroplasticity, memory, and the ability to process new information. In addition, continuous training allows you to maintain a high level of education and acquire skills not only in the professional field, but also in related fields. It is also a great way to adapt to the changing labor market, where new in-demand professions are emerging. At the same time, it is not necessary to start with learning a foreign language or mastering an entire specialty. You can start small: for example, solve puzzles and puzzles, solve crosswords or Sudoku, go on quests with friends. The main thing is to form a habit and engage in brain—healthy activities regularly.
Finally, a few more tips that will help you not to quit your studies halfway:
Define the learning goal and constantly remind yourself of it. This way you are more likely to be able to focus on the learning process and not be sprayed on other tasks.
Follow a clear curriculum: determine when during the day you can devote time to study and not be distracted by extraneous tasks — this will help form a habit and fit the schedule of classes into the routine.
Try to be interested in what is happening in the field you are studying outside of classes — for example, take an interest in the stories of people who have graduated from the same courses to maintain motivation.
Try to immediately apply the newly acquired skills — this will help to consolidate them.
Don't be afraid to ask for help from a mentor or fellow students.
And don't forget about the rest: this is important to avoid burnout.
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