title: Exploring the role of cognitive reserve and emotional modulation: implications for executive functioning in sensory and neuromodulatory interventions in ageing
Creators: name: Frau, L
Publisher: name: Liverpool John Moores University
Year: 2025

description: When age- or disease-related brain changes occur, individual differences in cognitive abilities can influence how efficiently a person can cope with these changes. The concept of cognitive reserve (CR, Stern, 2002, 2009) posits that certain lifetime experiences or stimulating activities (e.g., leisure activities, cognitive stimulation, work attainment) can improve the efficiency and flexibility of cognitive processes and brain networks. It is believed that CR may act as a protective factor in mitigating the detrimental impacts of age-related changes or brain diseases such as Mild Cognitive Impairment (MCI) or dementia. High CR is typically associated with the efficient and flexible use of top-down emotional regulation (Huang et al., 2019) and overall executive abilities (Cabeza &amp; Dennis, 2012; Tucker &amp; Stern, 2011). Executive function (EF) refers to a set of highlevel cognitive abilities, such as working memory, decision-making, and inhibitory control (Diamond, 2013), which are considered essential in supporting compensatory mechanisms of CR against cognitive decline (Cabeza, 2002; Tucker &amp; Stern, 2011). Research indicates that, in particular, individuals with depression, exhibit deficits in both emotional processing and EF due to the diminished functional connectivity within prefrontal-limbic circuits (Price &amp; Duman 2020). This can also lead to impairments in neuroplasticity and susceptibility to brain diseases, such as Mild Cognitive Impairment (MCI) and dementia (Bennet &amp; Thomas, 2014; Price &amp; Duman 2020). As a result, it is crucial for researchers to focus on developing efficient strategies or interventions that foster a positive affective state in order to support cognitive resilience and function. Many studies have employed various emotional techniques to elicit a positive affective state (Siedlecka &amp; Denson, 2019), leading to increased emotional self-regulatory capacity, which is crucial for mitigating the physiological effects of stress and achieving goals (Aldao, Sheppes, &amp; Gross, 2015). This capacity, which is linked to the autonomic nervous system (Thayer &amp; Lane, 2000), involves maintaining focus and emotional control in demanding tasks (Valenti, Garcia, &amp; Galera, 2021). By modulating the affective state, specifically its arousal levels such as heart rate variability, individuals can maintain a positive mindset, exhibit cognitive resilience in the face of adversity, and lately employ adaptive and flexible strategies to address distracting or irrelevant information (Thayer &amp; Lane, 2000). Despite experiencing age-related physiological changes (Jandackova et al., 2016), older adults exhibit improved emotional regulation compared to younger individuals (Carstensen &amp; Mikels, 2005). This means that interventions aimed at further improving emotional modulation might benefit older adults’ cognitive health, thus highlighting the relationship between emotional and cognitive processes (Gray, 2001) in the context of ageing. The current doctoral thesis is structured into ten chapters which serve to introduce the reader to the background and purpose of this research project. Chapter 1 describes the normal and pathological mechanisms of ageing associated with cognitive decline and MCI /dementia as well as the protective role of CR in mitigating cognitive decline and preventing brain pathology in the elderly population. By reviewing the main theoretical models and findings from the literature, Chapter 2 outlines how executive abilities, particularly working memory and inhibitory control capacity, may serve as compensatory mechanisms against age-related cognitive decline. In Chapter 3, we explore the relationship between EF and affective states, highlighting the potential role of emotional modulation in optimising cognitive control in response to high cognitive demand tasks. Next, Chapter 4 delves into the most widely accepted and effective interventions or techniques such as non-invasive brain stimulation used to improve EF in research. After describing the methodology in Chapter 5, the subsequent chapters (Chapters 6-9) provide an in-depth account of the studies that were conducted (for a more comprehensive overview of each study, refer to the sections below). Lastly, Chapter 10 serves as a summary of the results and implications of each study. It also discusses the limitations of the research and offers suggestions for further exploration and development in the field of ageing research.