There are more and more older people in today’s societies. Elderly people suffer from cognitive decline. It is beneficial for governments and businesses to prevent this, because cognitive decline will cause costs and risks. Brain plasticity and the role it plays in brain adaptation to ageing is influenced by comorbidities, environmental factors, personality traits, and genetic and epigenetic factors. Here will be reviewed the ways that age-related cognitive decline can be prevented.

Introduction

The brain of older people still adapts to physical, cognitive and social environments, while at the same time they are dealing with a decline in sensory-motor and cognitive abilities. Neuroplasticity is the brain response to decreasing physical and cognitive abilities in ageing. It refers to the ability of the brain to adapt to an environmental change by modifying neural connectivity and brain function in response to changing environments. Neuroplasticity does not refer to any improvements, but to preservation of a reduction in the rate of decline.

Theories of ageing on neuroplasticity

Ageing should not be seen as a declining process that eventually leads to cognitive deficits. Instead, it should be seen as a dynamic set of gains and losses. The brain has a certain plasticity and adapts to the losses and makes up for it with certain gains.

Scaffolding theory

The scaffolding theory of ageing and cognition states that the increased frontal activity with age is an indicator of brain adaptation. It is a reaction of the brain to some of the declines that are happening. Through training, ‘scaffolding’ can be strengthened. There is also a STAC-revisited theory, which incorporates lifestyle factors. It introduces two new constructs. Neural resource enrichment takes into account the influences that improve brain structure or functioning (e.g. intellectual and social activities). Neural resource depletion refers to negative influences on the brain structure or functioning (e.g. smoking, diabetes).

Cognitive reserve theory

The cognitive reserve hypothesis explains why individuals engaged in higher levels of mental and physical activity are at a lower risk for developing dementia. Cognitive reserve refers to a shift of task processing. The brain starts using a different part of the brain which is normally not used for that task.

Social engagement theory

Social engagement refers to participation in social activities that maintain and create social ties in real life activities and reinforce meaningful social roles. It is about the person making social and emotional connections. The model will include ‘upstream factors’, which are culture, socioeconomic and political factors, and the structure of the social network ties, their density and direction. It will also include ‘downstream factors’, which are social support, access to resources, social influence, health behaviors, and psychological and physiological pathways.

A lot of research shows that how important social networking and ‘belonging’ are for brain development. Wanting to belong gives rise to a set of neuronal networks that are genetically transmitted as a specific phenotype of social cognition. Social cognition is very important for social functioning and communication.

How to improve cognition

Research shows that training that is aimed at physical activity, cognitive training, and social engagement in older adults are effective when it comes to improving performance in the trained task. This is however only immediately after the training. More research needs to be done to see if the improvements are transferable to untrained tasks, and if the improvements last over time.

Important results

Looking at the different kinds of interventions, the following can be considered to be important results:

• With regards to exercise training, such as aerobics, the results indicate improvements in cognitive functioning, the ageing brains’ functional efficiency in cognitive networks, memory processing, executive control, controlled processing and processing speed.

• With regards to complex activities in which physical activity is one of them, such as dancing, the results show improvements in cognitive performance, posture, balance parameters, reaction time, working memory. Also this kind of training can help preserve cognitive, motor and perceptual abilities.

• With regards to physical activity in a sportive environment, such as martial arts, the results indicate improvements in physical function, postural control, visual-spatial attention, dynamic visual acuity, working memory and information processing speed. They also indicate a reduced risk of falls, depression and anxiety.

• With regards to computerized brain training the results are mixed. There is evidence showing transfer, and evidence showing a lack of transfer. Memory-training interventions can improve long-term episodic memory in healthy older people, but more research is necessary to investigate transfer of learnt skills.

• With regards to videogame training the results are mixed. There seem to be small improvements in some cognitive domains, but no changes in executive functions. More research needs to be done to investigate transfer and maintainability.