Memory and aging
Encyclopedia
One of the key concerns of older adults is the experience of memory loss
, especially as it is one of the hallmark symptoms of Alzheimer's disease
. However, memory loss is qualitatively different in normal aging from the kind of memory loss associated with a diagnosis of Alzheimer's. Occasional lapses in memory are normal in aging adults, and understanding the distinction between normal symptoms and warning signs of Alzheimer’s is critical.
(AD), known as mild cognitive impairment
(MCI). Many people who experience mild cognitive impairment are at a high risk of developing Alzheimer’s disease. Several studies have indicated that MCI individuals are at an increased risk for developing AD, ranging from 1% to 25% per year; 24% of MCI patients progressed to AD in 2 years and 20% more over 3 years, whereas a recent study indicated that the progression of MCI subjects was 55% in 4.5 years.
shows decline in both cross-sectional and longitudinal studies. Studies comparing the effects of aging on episodic memory
, semantic memory
, short-term memory
and priming
find that episodic memory is especially impaired in normal aging; some types of short-term memory are also impaired. The deficits may be related to impairments seen in the ability to refresh recently processed information. Source information is one type of episodic memory that suffers with old age; this kind of knowledge includes where and when the person learned the information. Knowing the source and context of information can be extremely important in daily decision-making, so this is one way in which memory decline can affect the lives of the elderly. Therefore, reliance on political stereotypes is one way to use their knowledge about the sources when making judgments, and the use of metacognitive knowledge gains importance. This deficit may be related to declines in the ability to bind information together in memory during encoding and retrieve those associations at a later time.
In particular, associative learning, which is another type of episodic memory, is vulnerable to the effects of aging, and this has been demonstrated across various study paradigms. This has been explained by the Associative Deficit Hypothesis (ADH), which states that aging it associated with a deficiency in creating and retrieving links between single units of information. This can include knowledge about context, events or items. The ability to bind pieces of information together with their episodic context in a coherent whole has been reduced in the elderly population. Furthermore, the older adults’ performances in free recall involved temporal contiguity to a lesser extent than for younger people, indicating that associations regarding contiguity become weaker with age.
Several reasons have been speculated as to why older adults use less effective encoding and retrieval strategies as they age. The first is the “disuse” view, which states that memory strategies are used less by older adults as they move further away from the educational system. Second is the “diminished attentional capacity” hypothesis, which means that older people engage less in self-initiated encoding due to reduced attentional capacity. The third reason is the “memory self-efficacy,” which indicates that older people do not have confidence in their own memory performances, leading to poor consequences.
A biological explanation for memory deficits in aging includes a postmortem examination of five brains of elderly people with better memory than average. These people are called the "super aged,” and it was found that these individuals had less fiber-like tangles of tau protein than in typical elderly brains. However, a similar amount of amyloid plaque was found.
The Mayo Clinic has suggested seven steps: stay mentally active, socialize regularly, get organized, eat a healthy diet, include physical activity in your daily routine, and manage chronic conditions. Because some of the causes of memory loss include medications, stress, depression, heart disease, alcohol abuse, thyroid problems, vitamin B12 deficiency, not drinking enough water, and not eating nutritiously, fixing those problems could be a simple, effective way to slow down dementia. Some say that exercise is the best way to prevent memory problems, because that would increase blood flow to the brain and perhaps help new brain cells grow. A healthy diet is also critical, partly because it has been demonstrated that healthy eaters are much less likely to develop Alzheimer’s disease.
The treatment will depend on the cause of memory loss, but various drugs to treat Alzheimer’s disease have been suggested in recent years. There are four drugs currently approved by the FDA for the treatment of Alzheimer’s, and they all act on the cholinergic system: Donepezil (Aricept), Galantamine (Reminyl), Rivastigmine (Exelon), and Tacrine (Cognex). Although these medications are not the cure for Alzheimer’s, symptoms can be reduced to mild dementia.
Also, modality is important in determining the strength of the memory. For instance, auditory creates stronger memory abilities than visual. This is shown by the higher recency and primacy effects of an auditory recall test compared to that of a visual test. Research has shown that auditory training, through instrumental musical activity or practice, can help preserve memory abilities as one ages. Specifically, in Hanna-Pladdy and McKay's experiment, they tested and found that the # of years of musical training, all things equal, leads to a better performance in non-verbal memory and increases the life span on cognition abilities in one's advanced years.
Another important aspect that helps memory as one ages is spacing. Spacing improves and facilitates the inductive and repetition learning, while mass learning is not helpful in improving memory (which is contrary to what the participants thought).
, typically shows no decline with age. Other types of short-term memory show little decline, and semantic knowledge (e.g. vocabulary) actually improves with age. In addition, the enhancement seen in memory
for emotional events is also maintained with age.
Recently, experiments that have tested for the significant of under performance of memory for an older adult group as compared to a young adult group, hypothesized that the deficit in associate memory due to age can be linked with a physical deficit. This deficit can be explained by the inefficient processing in the medial-temporal regions. This region is important in episodic memory, which is one of the two long-term human memory, and it contains the hippocampi, which is crucial in creating memorial association between items.
Second, the higher tendency for older people to make outside intrusions during a memory test can be attributed to the inhibition effect. Inhibition caused participants to take longer time in recalling or recognizing an item, and also subjected the participants to make more frequent errors. For instance, in a study using metaphors as the test subject, older participants rejected correct metaphors more often than literally false statements.
when remembering information, which seems to be a result of the increased focus on regulating emotion seen with age. For instance, eye tracking
reveals that older adults showed preferential looking toward happy faces and away from sad faces.
Memory loss
Memory loss can be partial or total and it is normal when it comes with aging. Sudden memory loss is usually a result of brain trauma and it may be permanent or temporary. When it is caused by medical conditions such as Alzheimers, the memory loss is gradual and tends to be permanent.Brain trauma...
, especially as it is one of the hallmark symptoms of Alzheimer's disease
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
. However, memory loss is qualitatively different in normal aging from the kind of memory loss associated with a diagnosis of Alzheimer's. Occasional lapses in memory are normal in aging adults, and understanding the distinction between normal symptoms and warning signs of Alzheimer’s is critical.
Mild cognitive impairment
Recent research has identified a transitional state between the cognitive changes of normal aging and Alzheimer's diseaseAlzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
(AD), known as mild cognitive impairment
Mild cognitive impairment
Mild cognitive impairment is a brain-function syndrome involving the onset and evolution of cognitive impairments beyond those expected based on the age and education of the individual, but which are not significant enough to interfere with their daily activities...
(MCI). Many people who experience mild cognitive impairment are at a high risk of developing Alzheimer’s disease. Several studies have indicated that MCI individuals are at an increased risk for developing AD, ranging from 1% to 25% per year; 24% of MCI patients progressed to AD in 2 years and 20% more over 3 years, whereas a recent study indicated that the progression of MCI subjects was 55% in 4.5 years.
Memory decline in normal aging
Normal aging is associated with a decline in various memory abilities in many cognitive tasks; the phenomenon is known as age-related memory impairment (AMI) or age-associated memory impairment (AAMI). The ability to encode new memories of events or facts and working memoryWorking memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...
shows decline in both cross-sectional and longitudinal studies. Studies comparing the effects of aging on episodic memory
Episodic memory
Episodic memory is the memory of autobiographical events that can be explicitly stated. Semantic and episodic memory together make up the category of declarative memory, which is one of the two major divisions in memory...
, semantic memory
Semantic memory
Semantic memory refers to the memory of meanings, understandings, and other concept-based knowledge unrelated to specific experiences. The conscious recollection of factual information and general knowledge about the world is generally thought to be independent of context and personal relevance...
, short-term memory
Short-term memory
Short-term memory is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory is believed to be in the order of seconds. A commonly cited capacity is 7 ± 2 elements...
and priming
Priming
Priming may refer to:* Priming , a process in which the processing of a target stimulus is aided or altered by the presentation of a previously presented stimulus....
find that episodic memory is especially impaired in normal aging; some types of short-term memory are also impaired. The deficits may be related to impairments seen in the ability to refresh recently processed information. Source information is one type of episodic memory that suffers with old age; this kind of knowledge includes where and when the person learned the information. Knowing the source and context of information can be extremely important in daily decision-making, so this is one way in which memory decline can affect the lives of the elderly. Therefore, reliance on political stereotypes is one way to use their knowledge about the sources when making judgments, and the use of metacognitive knowledge gains importance. This deficit may be related to declines in the ability to bind information together in memory during encoding and retrieve those associations at a later time.
In particular, associative learning, which is another type of episodic memory, is vulnerable to the effects of aging, and this has been demonstrated across various study paradigms. This has been explained by the Associative Deficit Hypothesis (ADH), which states that aging it associated with a deficiency in creating and retrieving links between single units of information. This can include knowledge about context, events or items. The ability to bind pieces of information together with their episodic context in a coherent whole has been reduced in the elderly population. Furthermore, the older adults’ performances in free recall involved temporal contiguity to a lesser extent than for younger people, indicating that associations regarding contiguity become weaker with age.
Several reasons have been speculated as to why older adults use less effective encoding and retrieval strategies as they age. The first is the “disuse” view, which states that memory strategies are used less by older adults as they move further away from the educational system. Second is the “diminished attentional capacity” hypothesis, which means that older people engage less in self-initiated encoding due to reduced attentional capacity. The third reason is the “memory self-efficacy,” which indicates that older people do not have confidence in their own memory performances, leading to poor consequences.
A biological explanation for memory deficits in aging includes a postmortem examination of five brains of elderly people with better memory than average. These people are called the "super aged,” and it was found that these individuals had less fiber-like tangles of tau protein than in typical elderly brains. However, a similar amount of amyloid plaque was found.
Prevention and treatment
Various actions have been suggested to prevent memory loss or even improve memory.The Mayo Clinic has suggested seven steps: stay mentally active, socialize regularly, get organized, eat a healthy diet, include physical activity in your daily routine, and manage chronic conditions. Because some of the causes of memory loss include medications, stress, depression, heart disease, alcohol abuse, thyroid problems, vitamin B12 deficiency, not drinking enough water, and not eating nutritiously, fixing those problems could be a simple, effective way to slow down dementia. Some say that exercise is the best way to prevent memory problems, because that would increase blood flow to the brain and perhaps help new brain cells grow. A healthy diet is also critical, partly because it has been demonstrated that healthy eaters are much less likely to develop Alzheimer’s disease.
The treatment will depend on the cause of memory loss, but various drugs to treat Alzheimer’s disease have been suggested in recent years. There are four drugs currently approved by the FDA for the treatment of Alzheimer’s, and they all act on the cholinergic system: Donepezil (Aricept), Galantamine (Reminyl), Rivastigmine (Exelon), and Tacrine (Cognex). Although these medications are not the cure for Alzheimer’s, symptoms can be reduced to mild dementia.
Also, modality is important in determining the strength of the memory. For instance, auditory creates stronger memory abilities than visual. This is shown by the higher recency and primacy effects of an auditory recall test compared to that of a visual test. Research has shown that auditory training, through instrumental musical activity or practice, can help preserve memory abilities as one ages. Specifically, in Hanna-Pladdy and McKay's experiment, they tested and found that the # of years of musical training, all things equal, leads to a better performance in non-verbal memory and increases the life span on cognition abilities in one's advanced years.
Another important aspect that helps memory as one ages is spacing. Spacing improves and facilitates the inductive and repetition learning, while mass learning is not helpful in improving memory (which is contrary to what the participants thought).
Invertebrate models
There are several model systems for AMI, including nematodes, flies and bees. In the nematode, C. elegans, AMI includes age-related changes in associative learning and memory that are modulated by insulin/IGF-1 signal and serotonin/octomamine signalDomains of memory mostly spared
In contrast, implicit, or procedural memoryProcedural memory
Procedural memory is memory for how to do things. Procedural memory guides the processes we perform and most frequently resides below the level of conscious awareness. When needed, procedural memories are automatically retrieved and utilized for the execution of the integrated procedures involved...
, typically shows no decline with age. Other types of short-term memory show little decline, and semantic knowledge (e.g. vocabulary) actually improves with age. In addition, the enhancement seen in memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
for emotional events is also maintained with age.
Recently, experiments that have tested for the significant of under performance of memory for an older adult group as compared to a young adult group, hypothesized that the deficit in associate memory due to age can be linked with a physical deficit. This deficit can be explained by the inefficient processing in the medial-temporal regions. This region is important in episodic memory, which is one of the two long-term human memory, and it contains the hippocampi, which is crucial in creating memorial association between items.
Theories about memory and aging
First, the tests and data that show that as people age, the contiguity effect weakens. This is supported by the associative deficit theory of memory, which asserts old people's poor memory performance is attributed to their difficulty in creating and retaining cohesive episodes. The supporting research in this test, after controlling for sex, education, and other health-related issues, show that greater age was associated with lower hit and greater false alarm rates, and also a more liberal bias response on recognition tests.Second, the higher tendency for older people to make outside intrusions during a memory test can be attributed to the inhibition effect. Inhibition caused participants to take longer time in recalling or recognizing an item, and also subjected the participants to make more frequent errors. For instance, in a study using metaphors as the test subject, older participants rejected correct metaphors more often than literally false statements.
Qualitative changes
Most research on memory and aging has focused on how older adults perform less well at a particular memory task. However, recently researchers have also discovered that simply saying that older adults are doing the same thing, only less of it, is not always accurate. In some cases, older adults seem to be using different strategies than younger adults. For example, brain imaging studies have revealed that older adults are more likely to use both hemispheres when completing memory tasks than younger adults. In addition, older adults sometimes show a positivity effectPositivity effect
In psychology and cognitive science, the positivity effect is the tendency of people, when evaluating the causes of the behaviors of a person they like or prefer, to attribute the person's inherent disposition as the cause of their positive behaviors and the situations surrounding them as the cause...
when remembering information, which seems to be a result of the increased focus on regulating emotion seen with age. For instance, eye tracking
Eye tracking
Eye tracking is the process of measuring either the point of gaze or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement. Eye trackers are used in research on the visual system, in psychology, in cognitive linguistics and in product...
reveals that older adults showed preferential looking toward happy faces and away from sad faces.
See also
- Aging
- Aging movement controlAging movement controlNormal aging movement control in human is about the changes on the muscles, motor neurons, nerves, sensory functions, gait, fatigue, visual and manual responses, in men and women as they get older but who do not have neurological, muscular or neuromuscular disorder...
- Brain aging
- Childhood amnesiaChildhood amnesiaChildhood amnesia refers to the inability of adults to retrieve episodic memories before the age of 2-4 years, as well as the period before age 10 of which adults remember fewer memories than accounted for by the passage of time...
- Cognitive enhancement
- Life extensionLife extensionLife extension science, also known as anti-aging medicine, experimental gerontology, and biomedical gerontology, is the study of slowing down or reversing the processes of aging to extend both the maximum and average lifespan...
- List of life extension related topics
- MemoryMemoryIn psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
- Testamentary capacityTestamentary capacityIn the common law tradition, testamentary capacity is the legal term of art used to describe a person's legal and mental ability to make or alter a valid will. This concept has also been called sound mind and memory or disposing mind and memory....
External links
- Arnáiz E, Almkvist O - Neuropsychological features of mild cognitive impairment and preclinical Alzheimer's disease
- Budson AE, Price BH - Memory dysfunction
- Cabeza R - Hemispheric asymmetry reduction in older adults: the HAROLD model
- Hedden T, Gabrieli JD - Insights into the ageing mind: a view from cognitive neuroscience
- Isaacowitz DM, Wadlinger HA, Goren D, Wilson HR - Selective preference in visual fixation away from negative images in old age? An eye-tracking study
- Johnson MK, Hashtroudi S, Lindsay DS - Source monitoring
- Mather M, Carstensen LL - Aging and motivated cognition: the positivity effect in attention and memory
- Mitchell KJ, Johnson MK, Raye CL, Mather M, D'Esposito M - Aging and reflective processes of working memory: binding and test load deficits
- National Institutes of Health - Memory related resources
- Nilsson LG - Memory function in normal aging