Memory Across the Lifespan
7.7 Memory Across the Lifespan In a classic demonstration of learning and memory, Rovee-Collier (1999) placed mobiles over the cribs of 2-month-old infants, and then attached a ribbon that connected the mobile to their feet. It took only a few minutes for most infants to learn that by vigorously kicking they could make the mobile move, demonstrating a physical memory trace that had previ- ously been thought to be restricted to older infants. Her research prompted researchers to reconsider previous notions of infantile amnesia (also known as childhood amnesia), or an adult’s absence of lasting memories from infancy and early childhood. It had been thought that children could not remember in the same way that adults do until language acquisition allowed them to encode and rehearse information (Nelson, 1990).
Even though infants and young children demonstrate implicit memories for prior experi- ences, early memories begin to fade with age and become increasingly unreliable (e.g., Bauer & Larkina, 2014; Peterson, 2013). One sequential study asked children aged 4 to 13 to recall three of their “first memories.” At 2-year follow-ups, younger children were unable to recall their previous first memories. Even after cues were given from the initial interview, the mem- ories were still not recalled. First memories had essentially changed. It was not until the chil- dren were 10 years old that they began to consistently recall the same “earliest” memories (Peterson, Warren, & Short, 2011). So although we do have memories beginning at an early age, it is not clear which memories become part of the permanent memory trace. In addi- tion, adults do not always remember events from 2, 4, or 6 years ago either, if they are not reviewed. Lack of memory durability during childhood may not be an age-related phenom- enon at all, but instead may be a reflection of how a particular experience has been remem- bered over time.
Episodic Memory We understand the development of episodic memory a bit better. It grows rapidly in child- hood and then declines slightly in middle adulthood and more profoundly in late adulthood (Shing et al., 2010). Newer episodic memories, like remembering where we placed a package or the musical program of a recent concert, tend to be compromised with age. The physical deterioration of brain structures devoted to encoding is the likely cause of this change, but it does not necessarily indicate any particular problem, like dementia. Further, it is not as pronounced as many believe. When older people misplace keys, people often jokingly charac- terize this as a “senior moment”; when it happens to younger people, they simply “misplace their keys.” Regardless, early episodic memories remain relatively strong (Eakin, Hertzog, & Harris, 2014; Ward, Berry, & Shanks, 2013). Even adults with moderate dementia are able to describe the events surrounding the births of their children, their first home, and former jobs.
Section Review Identify and explain the three stages of memory.
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Section 7.7 Memory Across the Lifespan
Working Memory Working memory is often hypothe- sized to form the basis for overall tra- jectory of cognitive efficiency (Gilsky, 2007). However, separating specific memory processes from overall under- standing of cognitive development is complicated. Because working mem- ory includes the ability to mentally manipulate information, it is tied to executive control. Further, since areas in the frontal lobe that are associated with executive functions do not mature until early adulthood, it follows that these memory processes follow a simi- lar course that cannot be accounted for solely by increased knowledge (Cowan et al., 2015). There are paral- lel increases in processing speed and attentional resources as well.
There is evidence that although overall cognition remains strong during early adulthood and most of middle adulthood, working memory begins to decline shortly after it peaks (Jones, Stephens, Alam, Bikson, & Berryhill, 2015; Schaie, 2013). Declines in working memory are likely to become noticeable when there is a failure to use effective strategies for storage, which is only partly determined by experience; there is measureable volume loss in associated brain regions. These measurable physiological changes, including in neural circuitry and specific cortical regions of the brain, accelerate in middle to late adulthood (Macpherson et al., 2014; Wang et al., 2011). However, neural plasticity also explains why memory remains strong throughout middle adulthood, even in the face of physiological decline (Steffener, Brickman, Rakitin, Gazes, & Stern, 2009). It is worth reiterating that overall cognition, as measured in part by tasks of working memory, benefits from cognitive training, increased exercise, social- ization, and adopting a Mediterranean, DASH, or MIND diet (discussed in Chapter 6). Taken together, these findings indicate that we are inching closer to discovering ways to stabilize or reverse working memory decline in our aging population.
Semantic Memory Though we often associate aging with semantic memory loss, more often middle-aged adults have cognitive advantages over those who are younger, probably because life experiences assist in understanding concepts and encoding new information (Schaie, 2013). Among adults without dementia, semantic memory seems to remain strong throughout the lifespan, and newer information remains accessible. Older adults continue to gain semantic memory (Eakin et al., 2014; Ronnlund, Nyberg, Backman, & Nilsson, 2005). On the other hand, from time to time everyone has the experience of being unable to recall a word until it is jogged loose by a cue. This is known as the “tip of the tongue” phenomenon. In general, the frus- tration of not being able to recall the right words, a name, or a movie title becomes more
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A declining working memory becomes noticeable when strategies for memory storage become less effective, but it is possible to stabilize or reverse this decline.
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Summary & Resources
noticeable beginning in middle adulthood. Although this can be momentarily frustrating, there is no evidence that this phenomenon is associated with serious cognitive deficits (Fleis- chman & Gabrieli, 1998; Shafto, Burke, Stamatakis, Tam, & Tyler, 2007).
Section Review How does memory change across the lifespan?
Summary & Resources
Chapter Summary Both Piaget and Vygotsky believed that children actively construct their understanding of the world. Both theorists postulate that children build knowledge out of experience. Piaget felt that children maintain an independent, natural pursuit of knowledge by acting on the environment. By contrast, Vygotsky argued that development is largely the result of the social construct, including language, social resources, and immediate culture. While Piaget and Vygotsky were largely silent on how thought changes after childhood, others recognize that adults are better able to consider multiple points of view, pragmatism, moral judgment, and emotion. These developments replace some rules of logic and add more nuances to thinking processes.
According to information-processing views, cognitive development occurs within a feedback loop. We attend to information, and then it is processed in a way that it can be stored. Infor- mation is then compared with other memories and processed for output. Therefore, rather than the stage-like changes described by others, information processing is clearly concerned with incremental changes in thinking ability. Advancements in memory for language and numbers are examples of these small changes. Greater success in cognitive tasks, like formal schooling, is reflected in the gradual sophistication of perception, memory, and process- ing of stored information, overseen by an executive function. Neurocognitive evidence for this perspective exists as we see physiological development that coincides with behavioral changes. Another example of this juxtaposition of neurocognitive process and behavior occurs within the study of language development, a topic we will explore next.
Summary of Key Concepts Introduction to Piaget’s Cognitive Development Theory
• Piaget theorized that advancement in thinking is organized around increasingly sophisticated cognitive structures called schemas.
• Children adapt to demands of the environment through the processes of assimilation and accommodation.
• Children try to maintain a balance between assimilation and accommodation, a pro- cess Piaget called cognitive equilibration.
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