Mental Stimulation, Neural Plasticity, and Aging: Directions for Nursing Research and Practice

David E. Vance, Nicole M. Webb, Janice C. Marceaux, Sarah M. Viamonte, Anne W. Foote, Karlene K. Ball

Disclosures

J Neurosci Nurs. 2008;40(4):241-249. 

In This Article

Successful Aging Through Cognitive Strategies

Figure 1 illustrates that successful aging requires sufficient cognitive ability to negotiate and enjoy one's environment. With age-related cognitive declines, however, the ability to successfully age may be compromised, and mental stimulation and cognitive strategies are needed to maintain or compensate for such losses. In Figure 1, mental stimulation refers to methods that promote brain health through learning. Cognitive strategies are specific techniques that help people remember information; these techniques are useful when one is experiencing cognitive impairment. These mental stimulation and cognitive strategies can improve cognitive reserve, which supports cognition or can help compensate for loss of cognitive reserve. In Figure 1, cognitive reserve is represented as a dotted line to signify that it is somewhat malleable.

Figure 1.

Model of Mentally Stimulating Strategies and Cognitive Reserve.

Baltes and Baltes (1990) proposed a model of successful aging developed from a theory of adaptive development and effective life management through selective optimization with compensation (SOC; Baltes & Carstensen, 2003; Baltes & Smith, 2003). The theory describes the life course as having changes in both resources and goals. As humans, our course begins with a focus on personal gain and growth early in adulthood, and, as we age, the focus shifts toward minimizing declines. The three components of SOC are selection, optimization, and compensation.

Selection is described as voluntary and loss-based; it involves selecting or narrowing the range of domains (e.g., relationships, health, or personal identity) and specific goals (e.g., spending time with family, exercising regularly, or participating in cultural activities) to what is within our reach while sacrificing goals beyond our reach. For example, later in life when attention and memory may not be as keen as in young adulthood, the selection of cognitive tasks may be limited to daily living tasks such as self-care and managing a home instead of more esoteric goals such as pursuing a degree or learning a foreign language. Daily living tasks may be chosen because maintaining independence often is of primary importance for many older people (Marsiske, Lang, Baltes, & Baltes, 1995).

Optimization refers to the resources that can be used to achieve goals to attain a higher level of functioning. For example, an older adult may use mnemonic strategies to learn and retain information so he or she can pursue meaningful activities that require memory demands, such as coursework. In this sense, the older adult is optimizing his or her existing memory ability to retain its best-possible functioning.

Compensation refers to establishing or attaining new resources to counteract declines that threaten current levels of functioning. Older adults must optimize their independence or abilities by compensating in areas in which ability is lacking. An older adult with mild memory problems, for example, may devote memory resources to performing certain tasks, such as remembering to take medications. The adult may use mnemonic strategies such as pill dispensers and a watch alarm to facilitate medication adherence; these aids compensate for declining memory ability so he or she can reallocate attention to more worthwhile pursuits and interests. Such compensation strategies emphasize the role of adaptation in the process of successful aging, especially successful cognitive aging.

SOC is a developmental construct that explains the variety of common behaviors that serve as situation-specific processes used to obtain the most advantageous result through adaptation. This model helps to identify the behavioral, motivational, and cognitive processes involved in successful aging. As cognitive abilities become less efficient, adaptation strategies suggested through SOC to maintain and adjust to limitations are necessary for successful aging. Although minimizing physical disabilities and maintaining social networks are important components of successful aging (Rowe & Kahn, 1997), intact cognitive functioning also is a critical component of successful aging that may work to maintain capacity in other areas important for overall successful aging (Vance, Ball, Moore, & Benz, 2007).

Using successful aging and cognitive reserve as a guide to increase cognitive quality of life, Table 1 and Figure 1 represent a general taxonomy through which maintaining or compensating for cognitive loss can facilitate successful aging. Although these strategies are by no means exhaustive, they demonstrate how mental stimulation may be used to expand cognitive reserve or compensate when cognitive reserve declines.

Maintaining or Improving Cognitive Abilities

Successful cognitive aging entails either improving or maintaining cognitive reserve to support overall cognition. Vance and Crowe (2006) proposed a model of neural plasticity and cognitive reserve in older adults that posited several steps to maintain or limit age-related loss, including a healthy lifestyle and engaging in mentally stimulating activities such as educational pursuits, novel experiences, and participating in cognitive remediation.

A healthy lifestyle likely provides the physiological foundation upon which neuronal health is supported, which in turn helps maintain or improve cognitive functioning. Avoiding conditions such as hypertension, pulmonary diseases, and diabetes has protective effects against subtle cognitive decline (Anstey & Low, 2004; Emery, Schein, Hauck, & MacIntyre, 1998). Also, higher levels of antioxidants have been associated with better cognitive functioning in older adults (Solfrizzi, Panza, & Capurso, 2003). Furthermore, several studies have shown the positive benefits of physical exercise on cognitive ability in older adults (Kramer, Hahn, & McAuley, 2000; Vance, Wadley, Ball, Roenker, & Rizzo, 2005).

Beyond maintaining a healthy lifestyle, mental stimulation also has been shown to help maintain or improve cognitive functioning either through education, a lifestyle of novel experiences, or cognitive remediation. Education remains one of the most salient predictors of cognitive functioning in later life. Several studies indicate that those who acquire more formal education experience a lower rate of developing cognitive impairments and dementia in later life (Milan et al., 2004; Whalley et al., 2004). Based upon neurological principles, these findings suggest that as more neural connections are made while learning, cognitive reserve and resistance to age-related changes increase. Likewise, those who pursue educational goals may be the same people who develop lifestyles of engaging novel experiences.

Emerging evidence demonstrates that individuals who engage in mentally stimulating activities across the life span have cognitive advantages over those who do not. In a national birth cohort, Richards, Hardy, and Wadsworth (2003) examined the association between cognitive ability and engaging in an active leisure life (e.g., playing musical instruments, bridge, chess). Controlling for education, gender, intellectual quotient at adolescence, recurrent illnesses, mental illness, and occupational social class, these researchers found that those who engaged in more physical activity and spare-time activities at 36 years of age had better memory performance at 43 years of age. Likewise, Grant and Brody (2004) discovered that older adults who had experience as a current or former orchestra member were less likely to develop or had delayed onset of Alzheimer disease. Similar to Diamond's (1993) experiments on an enriched environment for rats, these findings suggest that enriched participation helps to generate cognitive reserve to insulate people against age-related and pathological neurological decline.

Cognitive remediation therapy is another strategy through which cognitive ability within a certain domain of functioning (e.g., reasoning) can be maintained or improved. Cognitive remediation therapy typically incorporates carefully selected cognitive exercises designed to gradually improve cognitive ability. In the literature, cognitive remediation therapy has focused primarily on improving reasoning, memory, and speed-of-processing training (Vance, 2006; Vance, Ball, et al., 2007).

In the ACTIVE study, participants were randomly assigned to one of three cognitive remediation therapies: reasoning, memory, or speed-of-processing training. Training for the three therapies consisted of 10 1-hour sessions in which participants engaged in activities that required the use of a specific cognitive ability while being provided feedback. For the reasoning training, 620 community-dwelling older adults were taught to identify patterns in a logical serial pattern and translate this skill into everyday functioning. For the memory training, 627 community-dwelling older adults were provided training techniques and then practiced learning details using narratives, lists of words, and text materials. For the speed-of-processing training, 637 community-dwelling older adults worked to identify objects on a computer screen at increasingly faster presentation speeds; this therapy was designed to improve visual information processing speed. Results from this training showed that 74%, 26%, and 87% of the reasoning, memory, and speed-of-processing participants, respectively, exhibited reliable cognitive improvement in the domain for which they were trained (Ball et al., 2002).

Other studies investigating these training techniques also have found marked improvement in cognitive functioning after training (Floyd & Scogin, 1997; Vance, Dawson, et al., 2007). In fact, using magnetic resonance spectroscopy, one study found changes in hippocampal neurochemistry (i.e., increased creatine and choline signaling) after older adults participated in 5 weeks of focused memory training (Valenzuela et al., 2003). The hippocampus is the primary brain structure that encodes information and memories; this structure begins to shrink early in Alzheimer disease (Mace & Rabins, 1991). These studies show that cognitive ability and cognitive reserve are malleable, at least within certain individual parameters, and capable of improvement in older adults.

Compensating for Loss or Limitation of Cognitive Ability

When cognitive reserve decreases, it is necessary to compensate for such losses, as Baltes and Baltes (1990) suggested in the SOC model. A review of the psychological and cognitive aging literature provides a variety of compensation strategies that older adults can use to counter poor cognitive functioning, including declines in memory functioning. Table 1 and Figure 1 feature some of the better known strategies that are easy to apply, including method of loci, spaced retrieval, chunking, levels of processing, and external cues.

Method of loci is a paired associative strategy through which the learner links highly familiar places with information to be remembered. If an older adult wants to remember something like a phone number, for example, he or she can pair each number in sequence with a place with which he or she is familiar, such as a house, a neighborhood, or a walking trail (Figure 2). At the beginning of a walking trail, for example, an older adult could imagine a large number 9 standing on the path. Then, at a baseball field a few yards down the trail, he or she could envision a large number 3 standing on the grass. Further down the trail at the corner with the big tree, the person could imagine a large number 4, and so forth. This technique is effective because it draws upon well-rehearsed visual information from one's personal history. The place or location must be highly salient for meaningful, associative learning to occur. Also, older adults must be capable of visualizing the environment in which items are to be paired in a sequence. This strategy remains a unique and, in some cases, an enjoyable strategy for learning new information (Solso, 1991).

Figure 2.

Example: Method of Loci.

Spaced retrieval is an easy-to-use technique through which an adult with a memory problem recalls a specific piece of information over progressively longer periods of time until it is firmly consolidated into his or her long-term memory. Typically, the person starts out by first memorizing a piece of information, such as a phone number, and then recalling it immediately. The person is then instructed to recall the number after 30 seconds, 1 minute, 2 minutes, 4 minutes, 8 minutes, and 16 minutes (16 minutes is considered the amount of time needed for long-term memory consolidation). If the older adult is unable to correctly recall the information at any point, it is reviewed once more, and then he or she is required to recall the information at the previous time duration at which the information was correctly recalled (Morrow & Fridriksson, 2006). Spaced retrieval has been shown to produce startling results in cognitively intact older adults as well as in adults aging with HIV, stroke, and dementia. Vance and Farr (2007) offer a worksheet and more details about this cognitive strategy.

Chunking is a simple technique whereby information is broken down into smaller and easier-to-remember parts or chunks. Again using the example of remembering a phone number, a local phone number is broken into two sections: the first three numbers and the last four numbers. It is easier to remember these two sections of the phone number separately and then put them together instead of trying to remember the entire seven-number sequence. This strategy works effectively because it generally is easier to recall fewer items than many items (Gleitman, 1995). As a result, this strategy is useful when working memory is compromised by advanced age, disease, or both.

Levels of processing is a strategy through which information is remembered by thinking about it at a deeper level. More effort and energy are expended in thinking about information at this level, so neural connections are considered stronger, which helps a person retain information (Craik & Lockhart, 1972; Wood, 1983). Often this method works when the person pairs the information with bits of information already known so that new connections can be formed. A person can learn the phone number 325-1787, for example, by processing the numbers at a deeper level. First, 325 (March 25) can be a friend's birthday, or history enthusiasts may know that 1787 was the year in which Western civilization switched to the Gregorian calendar. The phone number then becomes a combination of a birth date and the start of the Gregorian calendar. Tulving and Madigan (1970) refer to this as "elaboration coding."

Use of external cues probably is the simplest and most straightforward strategy for retaining information. Calendars, desk organizers, notebooks, watches, cell phones, and a variety of other external aids are available. External cues work only if the person remembers to use them consistently, however. And some aids may be difficult to use, especially if they require knowledge of technology. The cognitive strategies discussed earlier, however, may prove most beneficial because information can be recalled if external cues are absent.

Combining cognitive strategies also is helpful. In a group of older adults with HIV and memory problems, Neundorfer and colleagues (2004) used both external cues and spaced retrieval strategies to help subjects perform certain goals such as remembering to go to doctors' appointments and taking medications. Researchers found that 90% of participants mastered their goals after four or five sessions. Likewise, Lekeu, Wojtasik, Van der Linden, and Salmon (2002) taught adults with early-stage Alzheimer disease to use a mobile phone. Simple, easy-to-read instructions were printed on the back of the phones; the researchers successfully used spaced retrieval to help subjects remember to use the instructions.

Spaced retrieval also can be paired with chunking. For example, in remembering a phone number, spaced retrieval can be used to learn the first three numbers (i.e., the first chunk of the phone number), then to learn the last four numbers (i.e., the last chunk of the phone number), and then to learn to put both chunks together. Cognitive strategies can be combined in endless ways to work for adults compensating for memory problems.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....