Understanding the aging brain

Where did I put the key? What was that actress’s name again? And why does multitasking suddenly feel more tiring than it used to? Moments like these are part of getting older – and they unsettle many people. The brain stores our memories, shapes our personality, and controls our decisions and emotions. When changes occur here, they affect not only our cognitive functions but also our sense of self.

“But aging does not necessarily mean decline,” says Marisa Koini. At the Department of Neurology in the research area of Neuropsychology & Neuroscience, she studies age- and disease-related structural and functional changes in the brain, biomarkers and the associated changes in cognition (memory, attention, language, orientation, etc.), as well as digital technologies.

“Understanding the aging brain means taking a holistic view: what is the baseline, what is still age-appropriate and what is already abnormal?” says the researcher. Her vision is to develop a digital twin that takes into account not only biological variables (e.g. hippocampal atrophy) but also lifestyle factors (e.g. physical activity, sleep, social isolation) and environmental factors (e.g. air pollution/particulate matter) in the prognosis, diagnosis and simulation of cognitive trajectories.

What happens in the brain as we get older?

As we age, certain processes in the brain slow down. Information is processed slightly more slowly, names or terms sometimes don’t come to mind immediately, and we think: “It’s on the tip of my tongue.”

This can also affect activities of daily living – for example, when driving, when it comes to orientation, when handling money or when doing household chores. At the same time, other abilities remain surprisingly stable or even continue to develop. These include, for example, experience, general knowledge, expert knowledge, emotional stability, lower stress sensitivity and the ability to make sense of complex situations.

From a neuropsychological perspective, aging is therefore not a uniform process, but highly variable both within and between individuals. Brains also age individually. The rate of brain aging depends on genetic predispositions, lifestyle, education, social experiences and health factors – and it proceeds independently of the initial cognitive baseline.

“The good news is: our brain remains malleable and capable of change well into old age. It can adapt both during learning and following certain types of damage, and can even compensate for deficits,” explains Marisa Koini. This adaptability is known as neural plasticity. It is one of the most important resources for healthy aging, helping to counteract factors such as a reduction in brain volume, thinning of the grey matter, changes in the white matter, or enlargement of the ventricles.

Neural plasticity refers to the brain’s ability to change and adapt structurally and functionally in response to experience, learning, the environment, ageing processes or even damage. Our brain is therefore not something rigid or unchangeable, but rather something dynamic that remains plastic and malleable well into old age.

Normal aging or early-stage dementia?

One of the most common concerns is: “Is this still normal or is it already a sign of illness?” Occasional forgetfulness is part of healthy aging. It becomes a cause for concern when memory problems significantly impair daily life: when familiar routes can no longer be found, conversations can no longer be followed, or tasks that were once taken for granted can no longer be performed.

An important distinction also lies in the experience of those affected themselves. Many people with early cognitive changes (Mild Cognitive Impairment, MCI) are well aware of these – often before those around them. They report increased effort, rapid exhaustion or the feeling of “not functioning quite as well as before”. However, these early signs are frequently overlooked or downplayed in daily life and should be investigated at an early stage.

“As part of a neurological assessment, a neuropsychological examination is also carried out at the Department for Neurology. This involves identifying possible deficits in memory, attention, executive functions, language and other areas. In addition to paper-and-pencil tests, computerised procedures are also used,” explains Marisa Koini.

Recognising and influencing risk

“Whether and how our brain ages is no coincidence. Studies show that there are numerous modifiable risk factors that contribute to cognitive decline or are considered risk factors for dementia,” explains Marisa Koini: lower educational attainment, impaired hearing, high cholesterol levels, depression, head injuries, physical inactivity, type 2 diabetes, smoking, high blood pressure, severe obesity, excessive alcohol consumption, social isolation and loneliness, air pollution, and declining eyesight. These factors – or rather their prevention, reduction and treatment – influence what is known as cognitive reserve, which can be understood as the brain’s resilience to age-related changes.

It is never ‘too late’. Even in later life, the brain and mind benefit from new challenges. What matters is not perfection, but regularity and variety. For instance, a foreign language or a musical instrument can be learnt even in retirement. Simply practising individual tasks rarely leads to broad improvements in everyday life. Activities that demand several skills simultaneously – attention, memory, planning and social interaction – are particularly effective. Together with physical activity and a balanced diet, they can have a positive effect on cognition. Digital training programmes using apps or virtual reality (VR) can help with this, particularly if they are well-adapted and meaningfully integrated. However, they are no substitute for an active, varied life. Crosswords and Sudoku alone are not enough – variety is the key.

Technology and dementia risk research: the future of early detection

Digital technologies such as adaptive tests with AI evaluation, sensor-based methods such as eye-tracking, wearables or voice recordings, virtual or augmented reality applications (e.g. navigation tests) or passive digital markers such as smartphone usage patterns open up new possibilities for detecting cognitive changes at an early stage. Combining these technologies with established methods and artificial intelligence models could assist doctors with early detection in the future. However, it does not replace face-to-face consultations and clinical experience.

The LETHE-AT project combines digital technologies with personal counselling to identify individual dementia risk at an early stage and reduce it in a targeted manner. The intervention study investigates whether changes in lifestyle factors (e.g. diet, physical activity, cognitive training) contribute to dementia prevention.

A total of 120 people are taking part in the study over an 18-month period. “The results will serve as the basis for developing an IT-supported hybrid prevention programme, as well as for creating guidelines and a roadmap for the introduction of so-called Brain Health Services – innovative next-generation memory clinics,” says Marisa Koini, describing the project’s aim. 

Participation is still open. Details at: https://www.lethe.at/

Tips for a healthy brain

1. Exercise: Regular physical activity promotes blood circulation and brain plasticity.
2. Social interaction: Conversations, relationships and shared activities provide measurable protection against cognitive decline.
3. Mental stimulation: Learn new things, vary your routines, stay curious.
4. Sleep and stress: Rest is not a luxury, but a prerequisite for memory and concentration.
5. Diet: A Mediterranean diet can protect the brain.