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.
Articles
Brain tissue is divided into two types: gray matter and white matter. These names derive very simply from their appearance to the naked eye. Gray matter is made up of the cell bodies of nerve cells. White matter is made up of the long filaments that extend from the cell bodies - the "telephone wires" of the neuronal network, transmitting the electrical signals that carry the messages between neurons.
The volume of gray matter tissue - a measure you will see cited in various reports - is a measure of the density of brain cells in a particular region.
Retrieval practice, as its name suggests, is a simple strategy that involves retrieving the target information one or more times prior to testing. It is not the same as repetition or rehearsal! The idea is not to simply repeat the correct information, but to try and retrieve it. Feedback as to the correct answer may or may not follow.
Do experts simply know "more" than others, or is there something qualitatively different about an expert's knowledge compared to the knowledge of a non-expert?
While most of us are not aiming for an expert's knowledge in many of the subjects we study or learn about, it is worthwhile considering the ways in which expert knowledge is different, because it shows us how to learn, and teach, more effectively.
I recently reported on a finding that older adults whose life-space narrowed to their immediate home were significantly more likely to have a faster rate of global cognitive decline or develop mild cognitive impairment or Alzheimer’s.
Prevalence
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.
Alzheimer's disease currently affects one in 10 people over age 65 and nearly half of those over age 85.
More than 19 million Americans say they have a family member with the disease, and 37 million say they know somebody affected with Alzheimer's.
In the United States, the average lifetime cost per Alzheimer patient is US$174,000. (These figures are from the U.S. Alzheimer's Association).
Vocabulary is a sticking point for many language learners. That’s because words have a certain arbitrary quality that makes them hard to memorize. There are two strategies which are very effective with this task: the keyword mnemonic, and retrieval practice. I have written about these extensively in my books Mnemonics for Study, and How to revise & practice.
In October I reported on a study that found older adults did better than younger adults on a decision-making task that reflected real-world situations more closely than most tasks used in such studies. It was concluded that, while (as previous research has shown) younger adults may do better on simple decision-making tasks, older adults have the edge when it comes to more complex scenarios. Unsurprisingly, this is where experience tells.
The limitations of working memory have implications for all of us. The challenges that come from having a low working memory capacity are not only relevant for particular individuals, but also for almost all of us at some points of our lives. Because working memory capacity has a natural cycle — in childhood it grows with age; in old age it begins to shrink. So the problems that come with a low working memory capacity, and strategies for dealing with it, are ones that all of us need to be aware of.