Memory Loss: What’s Normal, What’s Not
What Changes Are Normal as We Age
In order to identify signs and symptoms that are abnormal as with a cognitive disorder such as dementia or Mild Cognitive Impairment, it is necessary to understand what changes occur normally as we age. The National Institute of Mental Health has defined this gradual decline in memory as Age Associated Memory Impairment (AAMI). This is not a disease or disorder. It is simply a normal part of aging.
What does change as we grow older:
Short-term memory (the ability to learn new information) declines as we age. This is not a significant change, but it may be noticeable and it happens with most of us as we get older. Studies show that our short-term memory starts to decline in our 30s, but we don’t notice it until our 40s or 50s. At that time we begin employing methods that help us to compensate. It is much like needing reading glasses as we get older. As our short-term memory becomes weaker we may do a number of things to compensate such as writing more things down, keeping appointment books or day planners, using Post-It Notes, checklists, or wall calendars. Staying organized also helps. Keeping such items as keys, glasses, or cell phones in the same place at home and in the car saves us from misplacing them. Also, there is a gradual decline in the speed of the memory process itself — the retrieval of information takes longer and is a bit more difficult. However, if we are normal, even into our 80s and 90s we can still learn new information, and for the sake of brain health, we should keep learning new things. It takes a bit longer and it requires more effort, but we can still keep learning!
Our attention span gets weaker as we age. This, in turn, can affect memory because we have to attend to something just long enough to become registered and then stored into memory. We also have more difficulty when we have to divide our attention between two or more things. In other words, we are more easily distracted – it becomes harder to concentrate when too much is happening at once. We can compensate for this change by keeping stimuli to a minimum.
Our speed of information processing slows down. This is why you don’t see old fighter pilots or old pro quarterbacks. This is also why seniors tend to drive slower than younger drivers. Older adults need more time to process what they see and to react to situations and, therefore, compensate by driving slower. Of course, if a person’s driving has become so slow that they cannot keep up with the flow of traffic and get honked at by other drivers this suggests a problem that needs further evaluation.
Executive functioning declines. Executive function is the cognitive ability that is involved in the performance of the most complex activities of daily living such as working, driving, paying bills, managing finances, shopping, managing medications, preparing nutritious meals, and traveling alone. Executive function involves planning, organizing, sequencing, multitasking, paying attention, complex problem-solving, abstract reasoning, and the ability to shift attention back and forth between different stimuli quickly and accurately, such as when driving. It becomes more difficult to do several things at once (multitask), or to execute a smooth transition from one task to another. But once again this only becomes weaker and not impaired if we are normal for our age. We are still able to perform all the complex activities of daily living without much difficulty or any assistance.
What does not change as we grow older if we are normal for our age:
Immediate recall or registration does not decline. The person should be able to repeat back a string of five numbers or a name and address. If it takes the person 3 or 4 trials to repeat it correctly or the person cannot correctly repeat it after multiple trials, this indicates a problem that needs to be further evaluated.
Verbal intellect, the use of words, does not decline as we age, if we are normal. Our language ability does not decline with advancing age and may actually improve. This is due to the fact that we use our language skills constantly as we have our entire lives since a very young age. We watch television, converse with others, write letters or e-mails, read the newspaper or novels, play word games, etc. Our language skills are constantly being reinforced. Therefore, if a patient complains about having significant and ongoing word-finding difficulty or has difficulty understanding what others are saying to him or her, this should be considered clinically meaningful and in need of further evaluation. Also, if a family member reports that the loved one is talking less over time, has trouble expressing himself or herself verbally, becomes blocked in the middle of a conversation while searching for words, uses words incorrectly, or has difficulty naming familiar objects, then further evaluation is indicated.
Long-term memory remains essentially intact as we age. This has to do with the old information such as where we were born and raised, where we went to school, who our childhood friends were growing up, marriage and family experiences, military experiences, the type of work we did, etc. These memories stay intact throughout our lives. Even for individuals who develop dementia their oldest memories, habits, and patterns remain until the dementia is far advanced.
Intelligence does not decline significantly as we age. Not only is this true, but we also, if we are paying attention, learn a tremendous amount from life experiences and mistakes we make. We can also learn from other people’s mistakes. This is called observational learning. The result is we acquire a great deal of wisdom as we age. Jonas Salk said: “Wisdom is the ability to predict the future.” A sixty year old person, when confronted with a complex problem, would likely come up with a very different solution than a twenty year old, who is given the same problem to solve. John F. Kennedy said: “Wisdom comes from experience. Experience comes from making mistakes.”
Our ability to learn new information does not change significantly. It takes us longer to learn new information and it requires more effort, but we are still capable of learning as much as we could when we were younger.
What’s normal and what’s not:
Many patients complain about their difficulty remembering names. This greatly depends on what names they have difficulty remembering and this should always be explored further. Virtually everyone has difficulty remembering the names of new people we meet. This is not clinically meaningful. There are several reasons for this. First, when we meet someone we are often in the middle of a conversation and we do not have time to focus on the person’s name so that it is registered or repeated. Repetition improves learning of new information. Also, names are not descriptive. There usually is nothing about a person that can help with recall of their name unless the person’s name is associated with something about that person. For example, if someone nickname is “Red” and he has red hair this provides a cue that helps with our recall. We may know two people who have the same first name, but have absolutely nothing else in common.
When people cannot recall the names of people they should know then this indicates a problem. Older adults should be able to name their children and grandchildren. They should be able to remember their next door neighbor they have lived next door to for the past 20 years. They should, if they have lived in the U.S., most if not all of their lives, be able to name the current U.S. president, the president before him and the president who was killed in Dallas, Texas. They should be able to recall what event happened on September 11, 2001.
We have all had the experience of walking into a room and not remembering why we went into that room. If this happens every few weeks, there is nothing to worry about. We live busy lives and have many distractions. If it happens 3 or 4 times a week and certainly on a daily basis, this indicates that there is a problem that needs to be further evaluated. Daily problems with memory and thinking could indicate the presence of MCI or early dementia. However, these problems could also be caused by a number of other factors such as poor sleep, depression, stress, nutritional deficiencies, dehydration, medication side effects, endocrine imbalances, low blood sugar, or fatigue, to name just a few.
Common Causes for Normal Forgetfulness and Factors Affecting Memory:
- Not paying enough attention
- Sleep deprivation
- Low blood sugar
- Normal grief
Agronin, Marc E. Alzheimer Disease and Other Dementias (3rd Edition), Lippincott Williams & Wilkins, USA, 2014.
American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders
DSM IV-TR Fourth Edition (Text Revision) American Psychiatric Publishing; 4th Edition, 2000.
Budson, A.E. & Soloman, P.R. Memory Loss: A Practical Guide for Clinicians
Elsevier Health Sciences 2011.
Budson AE, Solomon PR. New criteria for Alzheimer disease and mild cognitive impairment: implications for the practicing clinician. Neurologist. 2012 Nov;18(6):356-63.
Caycedo AM, Miller B, Kramer J, Rascovsky K. Early features in frontotemporal dementia. Curr Alzheimer Res. 2009 Aug;6(4):337-40.
Crum, R.M., Anthony, J.C., Bassett, S. S., & Folstein, M.F. (1993) Population-based norms for the Mini-mental State Examination by age and education level, JAMA 269, 2386-2391.
Cummings JL, Dubois B, Molinuevo JL, Scheltens P. International Work Group criteria for the diagnosis of Alzheimer disease. Med Clin North Am. 2013 May;97(3):363-8.
Dash, P. & Villemarette-Pittman, N. Alzheimer’s Disease. AAN Press 2005.
Dobbs, B.M., Carr, D.B., & Morris, J.C. (2002). Evaluation and management of the driver with dementia. The Neurologist, Vol. 8/No.2
Folstein, M.F., Folstein, S.E. & McHugh, P.R. (1975) Mini-Mental State: A practical method for grading the cognitive state of patients for the clinician. Journ of Psychiatric Research, 12, 189-198.
Freedman, M., et al. Clock Drawing: A Neuropsychological Analysis.
Oxford University Press. 1994.
Gallo, Joseph J., Reichel, William & Anderson, Lillian M. Handbook of Geriatric Assessment, 2nd Edition Aspen Publishers, Inc., Gaithersburg, Maryland 1995.
Grundman, M., et al. Mild cognitive impairment can be distinguished from Alzheimer disease and normal aging for clinical trials. Arch Neurol. 2004 Jan;61(1): 11-27
Kuhn, Daniel Alzheimer’s Early Stages: First Steps for Families, Friends, and Caregivers
2nd Edition, Hunter House Publishers, Alameda, CA 2003.
Loring, D.W. (Editor) INS Dictionary of Neuropsychology and Clinical Neurosciences,
2nd Edition, Oxford University Press, New York 2015.
McKeith IG, Galasko D, Kosaka K et al. Consensus guidelines for the clinical and pathological diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DBL international workshop. Neurology 1996: 47:1113-1124.
Perry, R., McKeith, I., Perry, E. (Editors) Dementia with Lewy Bodies Clinical, Pathological, and Treatment Issues Cambridge University Press, United Kingdom, 1996.
Petersen, Ronald C. (Ed) Mild Cognitive Impairment: Aging to Alzheimer’s Disease
Oxford University Press, USA, 2003.
Petersen RC. Mild cognitive impairment as a diagnostic entity. J Intern Med. 2004-Sep;256(3): 183-94.
Petersen, R.C., Smith, G.E., Waring, S.C., Ivnik, R.J. Tangalos, E.G., Kokmen, E. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol.