Occupational Neuroplasticity in the Human Brain

Introduction

One of the characteristics of the human brain is its lifelong reorganization of both structure and function (Pascual-Leone et al., 2005). The term “neuroplasticity” refers to changes in function or structure that occur in the brain to adapt to external and/or internal factors (Zilles, 1992; Kempermann, 2006). The extent of neuroplastic remodeling depends on the relevance of individual changes and may have beneficial or maladaptive behavioral consequences (Pascual-Leone et al., 2005). It has been shown that enriched environments and physical activities can increase the growth rate of new neurons and their maintenance in adults (Kempermann et al., 1997; Gage, 2002). However, it is still not quite understood how human brain plasticity happens throughout the life cycle (Johansen-Berg and Duzel, 2016; Walhovd et al., 2016). For example, aging is related to a gradual loss of function in multiple systems, such as the systems underlying sensation, cognition (Kramer et al., 2004), memory (de Lange et al., 2017), motor control, and emotion (Mahncke et al., 2006). In animal models, research indicates that age limits the ability to adapt to changes (Wagner et al., 2000). In contrast, studies have also suggested that older people can quickly learn new skills through training and use them completely unsupervised most of the time (Mahncke et al., 2006; Boyke et al., 2008). The accumulation of age-related brain plasticity will inevitably lead to a growing mismatch between the functional capabilities of older people and what their environment requires of them, as structural plasticity is thought to occur only when demand exceeds capacity (Lövdén et al., 2010) or when there is a considerable change in environment (de Lange et al., 2017). Moreover, an interesting longitudinal study by Brouwer et al. (2017) estimated the heritability of subcortical and global brain volume changes in five sets of twins from geologically different locations and at different stages of life, revealing genetic variants specific to brain plasticity.

Neuroplasticity responds dynamically to environmental changes, and although it is usually beneficial and adaptive, some brain plasticity can be maladaptive in some situations. This paper focuses on the environmental factor of occupation, which subtly and continuously influences the brain through various other long-term and complex factors (e.g., repetition, skilled training, and social relationship) (Falk and Bassett, 2017). External factors act as modulators or inducers of human behaviors that are based on intrinsic structures and activities of the brain. Moreover, according to research findings on neuroplasticity, occupational neuroplasticity has multiple elements, including education, lifestyle, socioeconomic status, social relationships, sustained professional training, and experience. The role of occupational neuroplasticity in the human brain over the life span is not well-understood. Thus, in the following sections, we will fully explore and conclusively infer the neurological mechanisms related to occupational neuroplasticity through a meta-analysis of many published studies. Additionally, the rationality of the neurological findings, the relationship between occupational neuroplasticity and occupational science, and the limitations and future research will be discussed.