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Why our memories play tricks on usKEVIN LAMARQUE/Reuters

Collected Wisdom kicks off this week with an absolutely fascinating topic. It's about, er … um …

THE QUESTION: "Sometimes I cannot remember a name or a fact when I am in conversation with someone," writes Jean Weihs of Toronto. "That name or fact will pop up in my head a day or two later." How and why does this happen?

THE ANSWER: "Memory evolves throughout life and our capacity to 'bring up' stored information at a given time is also variable and dependent on multiple factors, many of which are still unknown to us," writes Angeles Garcia, president of the Consortium of Canadian Centres for Clinical Cognitive Research.

For many adults, says Dr. Garcia, the most effective way to remember ideas, names or facts is through association in a given context. However, because of the fluid and fast nature of conversation, we are often pressured and do not have the time to bring up the information we want, so we move on with the discussion.

She points out that "it takes much longer to write a fully informed response, with all the data we want to include, than to make a conversational oral response." It's more than just the difference between speaking and writing the same words, she says, and includes the time it takes to recall specific information. This "recall delay" is accentuated with aging.

However, we know less about why this information "pops up" later on, says Dr. Garcia. "Perhaps the piece of information we were searching for is related in our memory to a different context, or perhaps by releasing the attention control used while searching, we allow other memory resources to surface."

Also, she says, our brains are seldom at rest as networks continue to function after external stimuli have stopped. "Memory depends on the integrated circuitry function that includes several areas of the brain, and is intimately related to other cognitive domains, including attention." The relation among these other domains and memory might determine when and how a specific piece of information pops up.

THE QUESTION: "Why do ink cartridges cost so darned much?" asks Michael Hanlon of Cobourg, Ont. "I bought one the other day that contained a mere 1.35 fluid ounces of ink, about a third the size of a decent martini. The price: $46.58."

THE ANSWER: It's a classic "loss-leader" strategy, says Stuart Hartsook of Victoria. "Manufacturers sell printers at or below cost, knowing that once consumers own the printer they will likely purchase ink cartridges from the same manufacturer (because of brand association or printer incompatibility with other cartridges), thus allowing them to charge a premium on the ink."


  • Bill Somes of Sarnia, Ont., asks: In listing the lineage of a racehorse on a race form, why is there more emphasis on the male side of the breeding? "A racing program will show the sire and the dam as well as the dam's sire (and sometimes the sire's sire) but not sire's dam."
  • Why, on the Fahrenheit scale, does water freeze at 32 degrees and boil at 212? Chuck Mercer of Napanee, Ont., wants to know.

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