Several genes have been implicated in Alzheimer's, but the big one is the e4 allele of the ApoE gene (on chromosome 19). This variant is found in about a quarter of the population.
Having it doesn't mean you are foreordained to develop Alzheimer's, but it certainly increases the risk substantially. The risk goes up considerably more if both of your genes are the e4 variant (remember you inherit two: one from each parent).
Impaired vision is common in old age and even more so in Alzheimer’s disease, and this results not only from damage in the association areas of the brain but also from problems in lower-level areas. A major factor in whether visual impairment impacts everyday function is contrast sensitivity.
We're all familiar, I'm sure, with the use of worked-out examples in mathematics teaching. Worked-out examples are often used to demonstrate problem-solving processes. They generally specify the steps needed to solve a problem in some detail. After working through such examples, students are usually given the same kind of problems to work through on their own. The strategy is generally helpful in teaching students to solve problems that are the same as the examples.
Frontotemporal dementia is a disorder of the frontal lobes and includes what was known as primary progressive aphasia. Although it occurs far less often than Alzheimer's disease, among dementia sufferers younger than 65 it is estimated to occur at about the same rate. In other words, frontotemporal dementia is, unlike the most common dementias, not a disorder of age. Most sufferers become symptomatic in their 50s and 60s.
In a recent news report, I talked about how walking through doorways creates event boundaries, requiring us to update our awareness of current events and making information about the previous location less available. I commented that we should be aware of the consequences of event boundaries for our memory, and how these contextual factors are important elements of our filing system. I want to talk a bit more about that.
I recently reported on a finding that memories are stronger when the pattern of brain activity is more closely matched on each repetition, a finding that might appear to challenge the long-standing belief that it’s better to learn in different contexts. Because these two theories are very important for effective learning and remembering, I want to talk more about this question of encoding variability, and how both theories can be true.
First-letter mnemonics are, as their name suggests, memory strategies that use the initial letters of words as aids to remembering. This can be an effective technique because initial letters are helpful retrieval cues, as anyone who has endeavored to remember something by mentally running through the letters of the alphabet can attest to.
There are two types of first-letter mnemonic:
The evidence that diet, physical exercise, and mental stimulation all help prevent age-related cognitive decline and reduce the risk of mild cognitive impairment and Alzheimer’s, is now very convincing.
Studies of mice and (rather intriguingly) beagles, have provided evidence that ‘enriched’ environments — ones that provide opportunities for regular exercise and mental stimulation — reduce or prevent age-related cognitive decline, and reduce the risk of Alzheimer’s.
Vascular dementia, as its name suggests, is caused by poor blood flow, produced by a single, localized stroke, or series of strokes.
It is the second most common dementia, accounting for perhaps 17% of dementias. It also co-occurs with Alzheimer's in 25-45% of cases. Although there are other types of dementia that also co-occur with Alzheimer's, mixed dementia generally refers to the co-occurrence of Alzheimer's and vascular dementia.
In a recent news report, I talked about a study of older adults that found that their sense of control over their lives fluctuates significantly over the course of a day, and that this impacts on their cognitive abilities, including reasoning and memory.