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.
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How many words do you need to learn?
An analysis of English vocabulary* has found that the first 1000 words account for 84.3% of the words used in conversation, 82.3% of the words encountered in fiction, 75.6% of the words in newspapers, and 73.5% of the words in academic texts. The second 1000 accounts for about another 5% (specifically, 6% of conversation, 5.1% of fiction, 4.7% of newspapers, 4.6% of academic texts).
"Consolidation" is a term that is bandied about a lot in recent memory research. Here's my take on what it means.
Becoming a memory
Initially, information is thought to be encoded as patterns of neural activity — cells "talking" to each other. Later, the information is coded in more persistent molecular or structural formats (e.g., the formation of new synapses). It has been assumed that once this occurs, the memory is "fixed" — a permanent, unchanging, representation.
I want to talk to you this month about an educational project that’s been running for some years here in New Zealand. The Project on Learning spent three years (1998-2000) studying, in excruciating detail, the classroom experiences of 9-11 year olds. The study used miniature videocameras, individually worn microphones, as well as trained observers, to record every detail of the experiences of individual students during the course of particular science, maths, or social studies units.
"I'm terrible at remembering names"
"I'm great with names, but I'm hopeless at remembering what I've read."
"I always remember what people tell me about themselves, but I'm always forgetting birthdays and anniversaries."
There is no such thing as a poor memory!
There will be memory domains that you are less skilled at dealing with.
Information comes in different packages
Think about the different types of information you have stored in your memory:
Reading is a deceptive skill, for it is not a single process, but a number of processes. Thus, while you might be a fluent reader, in that you can swiftly and easily decode the letter-markings, and quickly access the meaning of the words, that doesn't mean you're a skilled reader of informational texts.
Let’s talk about the cognitive benefits of learning and using another language.
In a recent news report, I talked about the finding that intensive learning of a very novel language significantly grew several brain regions, of which two were positively associated with language proficiency. These regions were the right hippocampus and the left superior temporal gyrus. Growth of the first of these probably reflects the learning of a great many new words, and the second may reflect heavy use of the phonological loop (a part of working memory).
Distributed practice more effective than massed practice
It has long been known that spacing practice (reviewing learning or practicing a skill at spaced intervals) is far more effective than massed practice (in one heavy session). An interesting example of this comes from a study that aimed to find the best way of teaching postmen to type (this was at the request of the British Post Office). The researchers put postmen on one of four schedules:
Most cognitive processes decline with age
It does appear that most component processes of cognition decline with advanced age if the difficulty level is sufficiently high. For example, the following processes have all shown age effects:
What is neurogenesis?
Neurogenesis — the creation of new brain cells — occurs of course at a great rate in the very young. For a long time, it was not thought to occur in adult brains — once you were grown, it was thought, all you could do was watch your brain cells die!
Adult neurogenesis (the creation of new brain cells in adult brains) was first discovered in 1965, but only recently has it been accepted as a general phenomenon that occurs in many species, including humans (1998).