The Neuropsychology Of Aging

We all grow old. Like it or not, we know that our cells age over time and that both our physical appearance and our cognition will change over the years. One of the fields that deals with studying these changes at the neuronal level is the neuropsychology of aging.

According to the World Health Organization (WHO), from a biological point of view, aging is the consequence of the accumulation of a great variety of molecular and cellular damages over time, leading to a gradual decrease in the physical and mental ability. Furthermore, aging also leads to an increased risk of disease, and ultimately death.

However, in addition to biological changes, there are also other factors that influence aging. Thus, the physical and social environments also influence, particularly the home, the neighborhood and the communities that surround the person. In addition, the personal characteristics of each one (sex, ethnicity, socioeconomic level …) also have to do with how we age.

Normal and pathological aging

The neuropsychology of normal aging

The physiological changes that occur in normal aging can lead to functional losses, and depend on several factors :

  • Cognitive status.
  • Physical disability.
  • Emotional factors.
  • Intercurrent medical illnesses.
  • Quality of life…

Pathologies such as hypertension, diabetes, or cardiovascular diseases, over time, involve a loss of physical and functional capacities. Thus, for example, anxiety and depression increase the risk of developing cognitive impairment. In normal aging, the degree of loss of function is influenced by brain and cognitive reserve.

Cognitive reserve is the ability of the adult brain to maintain normal function when affected by aggression. Thus, the impact of aggressions is less the greater the cognitive reserve. This occurs because healthy brain tissue is able to supply the loss of neurons and synapses. Thus, in individuals with less cognitive reserve, the same pathology would produce a greater deficit.

In this sense, the neuropsychological model of aging focuses on the relationships between cognition and risk factors, protective factors, the brain, and the clinical status of patients. Thus, for the study of cognitive changes associated with age, some aspects of cognition are analyzed, such as:

  • Processing speed.
  • Attention.
  • Memory and learning.
  • Language.
  • Executive functions.
  • Premotor, visuoperceptive and visuospatial functions.

Tests associated with normal aging

On the general cognitive state, functional activity and mood:

  • Mini-mental state examination (MMSE).
  • Blessed Dementia Scale (BDS).
  • Functional Activity Questionnaire (FAQ).
  • Back Depression Inventory (BDI).
  • Information Subtest (WAIS-III).

On processing speed and attention:

  • Reaction times task (PC, Vienna System)
  • Paced Auditory Serial Addition Test (PASAT)
  • Trail Making Test (TMT-A)
  • Color Trails Test (CTT)

Finally, on visuospatial, visuoperceptive and visuoconstructive functions :

  • Structural magnetic resonance.
  • Functional magnetic resonance.

Cognitive changes in the neuropsychology of normal aging

In aging, the individual variability of each one is important, which leads us to present some or other changes in our body. However, there are several factors that contribute to this variability:

  • General health status: physical, mental and emotional
  • Cultural level
  • Level of physical and cognitive activity
  • Hereditary factors
  • Economic, social and family factors

Cognitive functions in the neuropsychology of normal aging

As we age, there are some cognitive functions that are more affected than others. Thus, aging affects fluid skills more than crystallized skills . The first are some such as reasoning, working memory, processing speed … etc. The second refer to accumulated knowledge and experience.

Thus, we know from research that the deterioration of some functions begins in youth, while others remain at the same level until advanced ages. In this way, some functions such as vocabulary, general information or the memory of past historical or personal episodes remain relatively stable.

Other functions, such as arithmetic ability, decrease after the age of 25. The speed of information processing, episodic memory and verbal fluency decrease after the age of 70.

Neuropsychology of pathological aging

In many of the pathologies associated with aging we find mild cognitive impairment (MCI). It is a “state” of cognitive impairment higher than that of the relevant age group, not meeting the criteria established for dementia. Thus, according to Petersen (2001), for the diagnosis of MCI the following symptoms must be observed for at least six months:

  • Subjective memory complaints, preferably revealed by reliable informants.
  • Subjective complaints from one or more cognitive areas, preferably revealed by reliable informants.
  • Cognitive impairment in memory or some other cognitive domain.
  • Activities of daily living preserved.
  • Absence of dementia.

Thus, it seems clear that, with age, cognitive functions decline. The population of elderly people is increasing and that is why mechanisms have to be put in place to improve their quality of life. The world must be prepared to deal effectively and comprehensively with the problems that may arise related to the progressive aging of the population.