This chapter discusses some of the current trends and promising future directions in the field of cognitive neuroscience of aging. The chapter first discusses recent research investigating the contribution of individual difference factors related to identify, including race, culture, and sex differences. Next, the chapter reviews recent research on neuromodulation, including ways in which noninvasive brain stimulation (e.g., repetitive transcranial magnetic stimulation [rTMS], transcranial direct current stimulation [tDCS], and transcranial alternating current stimulation [tACS]) has been used in an attempt to enhance cognition with age as well as with age-related disorders. This section also considers other approaches to neuromodulation, including deep-brain stimulation and neurofeedback. Finally, discussion of emerging directions considers the importance of investigating aging across the lifespan, studying the intersection of physical health with cognition, exploring the distinction of socioemotional and cognitive domains, and emphasizing the contribution of context with age.

This chapter considers the changes that occur with age-related disorders. For Alzheimer’s disease and amnestic mild cognitive impairment, the chapter reviews structural changes that occur in the brain and then turns to functional changes. These include coverage of changes related to memory and cognition, attention, and self and emotion. Next, neuroimaging research on amyloid and tau are reviewed, and some literature on relevant genes is discussed. The chapter then reviews literature on other age-related neurodegenerative diseases, considering effects on cognitive and social functions. These include Parkinson’s disease, Huntington’s disease, frontotemporal dementias (including progressive nonfluent aphasia, semantic dementia, behavioral variant frontotemporal dementia, and amyotrophic lateral sclerosis).

In the last few chapters we have considered financial and strategic decisions made within companies, and whether they improve the value of the company. In this chapter we continue examining company decisions, and focus on a particular financial decision—the payout decision, which considers whether a company keeps the cash it holds or gives it back to investors. As we will show, this decision is important because firms can potentially increase their value—and benefit their investors—through their choice of whether to pay out cash to investors. Furthermore, as we discussed in the previous chapter, agency problems may arise when companies hold onto large amounts of cash due to managerial conflicts of interest. Thus, payout can serve an important role in corporate governance.

This chapter reviews findings about the effects of aging on memory. Coverage includes working memory, encompassing processes such as refreshing and inhibition, as well as explicit and implicit long-term memory, and prospective memory. Within the topic of explicit long-term memory, specific topics include the levels of processing framework, subsequent memory paradigms, recollection, source memory, associative memory and binding, semantic memory, false memory, autobiographical memory, memory and future thinking, reactivation, controlled processes in long-term memory, event boundaries, and pattern separation.

In previous chapters we explored how to calculate the value of a company, given decisions that it had already made. In subsequent chapters we then focused on decisions that a manager within a company could make, and how they affect company value, such as project investment decisions. In this chapter we continue to examine decisions made by companies, and focus on a particularly important decision—the financing decision. Capital structure is the mix of financing sources that a firm uses to fund its operations, growth, and investment projects. A firm may choose to use internal funding from operations, or use external funding from issuing debt (bonds) or equity (stock), or other financing instruments.

In the previous chapter we discussed what risk is and how managing risk is an essential element of every financial decision. Risk stems from uncertainty about the future. In this chapter, we introduce and explain financial contracts—options—that help resolve uncertainty by allowing an asset to be traded at a fixed price in the future after observing outcomes. More specifically, put options allow the choice to sell or not sell an underlying asset in the future, while call options allow the choice to buy or not buy an underlying asset in the future. The owner does not have to sell (in the case of a put) or buy (in the case of a call) in the future if it is not beneficial to them. Thus, the value of option contracts is that they embed flexibility—the owner makes the decision after the market price of the underlying asset is observed.

In the previous chapter we went over the process by which investors form portfolios, how to measure the risk and return of a given portfolio, and how an optimal portfolio can be chosen from a riskless asset and a set of risky assets. We saw that the optimal portfolio consists of holding some portion of one’s money in the riskless asset and some portion in the tangency portfolio consisting of the optimal combination of risky assets (OCRA). In this chapter we introduce the capital asset pricing model (CAPM), which specifies exactly what the OCRA should be. The CAPM predicts, under a set of assumptions, that the OCRA consists of holding all assets in the market in proportion to their value. Thus, all investors should hold some combination of the market portfolio and the riskless asset because it is most efficient.

In Chapter 13 we saw that the general choice of financing—debt or equity—affected overall firm value only due to frictions such as agency problems or asymmetric information. Debt and equity financing can come from many different sources in the financial system, and the institutional details of these sources can introduce important considerations for the firms seeking financing. In this chapter we explore the different sources of financing that may be available and/or feasible for firms to use at various stages of their lives: from new startup firms to mature and stable publicly traded corporations. Broadly speaking, the global financial system successfully meets the financial needs of the many different types of firms that operate in the economy. However, firms are constantly in flux, and as a result so are their financial needs. While the financial sources we discuss in this chapter continue to be important to the financial system, in response to the evolving nature of firms, new financial innovations and different ways of financing are always being introduced.

This chapter reviews changes to cognition with age. This includes sections on attention, executive function, motor control, and language. After reviewing cognitive aging and these basic cognitive functions, the chapter considers the burgeoning literature on training cognitive ability with age. This section includes review of intervention programs focused on physical activity, mediation and mediation, cognitive activities, working memory training, and long-term memory training.