Memory Loss, Dementia, and Stroke: Implications for Rehabilitation of Older Adults with Age-Related Macular Degeneration

Abstract

As physiatrist Stanley Wainapel (2001, p. 59) observed, people have a bad habit: they do not develop problems in one system alone. They develop problems in many systems. Older adults with age-related macular degeneration (AMD) are not immune to the other diseases of aging. Although AMD is the leading cause of low vision in older Americans, stroke is the leading cause of disability (Rosamond et al., 2007), and dementias affect another 2.5 million older Americans (Plassman et al., 2007). Each condition alone can significantly impair a person's ability to participate fully in daily life, and these conditions often occur together (Crews, Jones, & Kim, 2006). This article describes impairment from memory loss, dementia, and stroke to provide insights into how these conditions may affect the visual rehabilitation of clients with AMD. MEMORY LOSS Memory is a complex cognitive process with many components, of which some are more susceptible to aging than others (Gazzaley, Sheridan, Cooney, & D'Esposito, 2007; Levy, 2001). The information-processing model (Atkinson & Shiffrin, 1968) is widely used to conceptualize the components of memory. According to the model, memory processing involves three sequential storage systems: sensory-perceptual, short term, and long term. Sensory-perceptual memory represents the first stage of processing. During this stage, sensory input from the environment (visual, auditory, and so forth) is captured and briefly replicated. If attended to, the input is encoded and transferred to short-term memory; if not, it is discarded. The second stage, short-term memory, is comprised of the information being consciously attended to at a specific moment. It involves an active interpretive process, called working memory, by which long-term memories are used to analyze the new information from sensory-perceptual memory for its meaning and application to the task at hand. Working memory enables one to focus attention, understand what is happening, reason, and make a decision. The final stage, long-term memory, has the largest storage capacity. It is comprised of three storage systems: episodic memory (facts or events), semantic memory (knowledge or beliefs about facts and events--wisdom), and procedural memory (sequences or patterns of behavior). Long-term memory is retrieved through two processes: recall and recognition. Recall is the ability to search memory to retrieve a specific piece of information (such as a date). Recognition retrieves memory by associating new input (like a name) with relevant events or cues (for example, the same name as a good friend). Memory loss is one of the symptoms that is most often associated with aging (Teri, McCurry, & Logsdon, 1997). While long-term episodic, procedural, and semantic memory remain mostly stable, age can reduce the short-term episodic memory involved in recalling day-to-day details (Levy, 2001). Difficulty recalling information begins after age 50, creating the why did I come into this room? scenario that is familiar to middle-aged and older adults. However, older adults generally demonstrate good recall of information when provided with cues (for instance, the sight of a telephone prompts a reminder to call one's son). Older adults with visual impairments may experience limitations in memory because they do not see visual details well enough to activate sensory-perceptual processing and establish visual memories. Modifying the environment to enhance the visibility of tasks is critical to enabling adults with low vision to establish memory. ha addition, Levy (2001) suggested several strategies to enhance memory processing when teaching new skills to a client: (1) allow time for the repetition and review of new information; (2) present information slowly, allowing for rehearsal and thinking out loud to facilitate concentration; (3) eliminate background noise and other distracters; (4) teach one concept at a time, logically grouping information to assist the client to identify relationships; (5) point out similarities between the new task and a familiar one; and (6) ensure that the skills being taught are relevant and important to daily living. …