Tag Archives: cognition

Gradual Sleep Deprivation, Obesity and Cognitive Impairment

By getting less than our required amount of sleep over an extended period of time (two weeks, for example) we are increasing our risk of obesity and impairing our cognitive abilities without even being aware of it.

That’s the conclusion from a short article summarising the surprising effects of gradual sleep deprivation:

Researchers […] restricted volunteers to less than six hours in bed per night for two weeks. The volunteers perceived only a small increase in sleepiness and thought they were functioning relatively normally. However, formal testing showed that their cognitive abilities and reaction times progressively declined [until] they were as impaired as subjects who had been awake continuously for 48 hours.

Moreover, […] too little sleep changes the body’s secretion of some hormones. The changes promote appetite, reduce the sensation of feeling full after a meal, and alter the body’s response to sugar intake—changes that can promote weight gain and increase the risk of developing diabetes. […]

A recent review […] of the large studies that followed people over time agreed that short sleep duration was associated with future weight gain. […] For example, [one study] showed an inverse correlation between sleep duration and obesity in high-school-age students. The shorter the sleep, the higher the likelihood of being overweight, with those getting six to seven hours of sleep more than two and a half times as likely to be overweight as those getting more than eight hours. […]

The good news is that these effects can be reversed by getting an adequate amount of sleep. […] Allowing the study subjects to sleep 10 hours for two consecutive nights returned the hormones to normal levels and lowered hunger and appetite ratings by almost 25 percent.

via @finiteattention

Scaling Success and Bright-Spot Analysis

When there is a large-scale and wide-ranging problem that needs a solution, we shouldn’t attempt to solve it with an equally large solution but instead attempt to break the issue down and find outlying successes to replicate.

That’s the wisdom of Dan and Chip Heath–authors of Made to Stick and Switch–saying that to solve complex problems we should change our way of thinking to ‘bright-spot’ analysis and attempt to scale small successes.

That’s the first step to fixing everything from addiction to corporate malaise to malnutrition. A problem may look hopelessly complex. But there’s a game plan that can yield movement on even the toughest issues. And it starts with locating a bright spot — a ray of hope. […]

Our rational brain has a problem focus when it needs a solution focus. If you are a manager, ask yourself, What is the ratio of the time you spend solving problems versus scaling successes?

We need to switch from archaeological problem solving to bright-spot evangelizing. […] Even in failure there is success. […]

These flashes of success, these bright spots, can provide our road map for action — and the hope that change is possible.

via @Ando_F

Cryptic Crosswords and Face Identification

A study comparing the effects of various leisure activities on the recognition and identification of faces has concluded that eyewitnesses should not be permitted to do cryptic crossword puzzles prior to an identity parade.

The study, conducted by Cardiff University’s Michael Lewis, compared logic puzzles (sudoku), crossword puzzles (both cryptic and standard) and mystery novels (Dan Brown’s The Da Vinci Code) and found that performing cryptic crosswords reduced the reliability of recognising and identifying faces.

“The identification of an offender by a witness to a crime often forms an important element of a prosecution’s case. While considerable importance is placed by jurors on the identification of the offender by a witness (such as a suspect being picked out from an identity parade), research tells us that these identifications can often be wrong and sometimes lead to wrongful convictions.”

“It would be undesirable,” he writes, “to have witnesses doing something before an identity parade that would make them worse at picking out the offender … Consider what witnesses may do before an identity parade. It is possible that they might be doing something to pass the time (eg read or do a puzzle). It is possible that some of these potential activities may lead to a detriment in face processing.”

via @noahWG

More on the Cognitive Benefits of Moderate Exercise

“There is overwhelming evidence that exercise produces large cognitive gains and helps fight dementia”, says the Harvard University psychologist John Ratey, author of the 2008 book on the subject, Spark.

While Ratey propounds the “very clear” link between exercise and mental acuity, saying that even moderate exercise pushes back cognitive decline by “anywhere from 10 to 15 years”, the National Institutes of Health are more cautious:

Looking at reducing the risk of “cognitive decline in older adults,” [the NIH] wrote: “Preliminary evidence suggests a beneficial association of physical activity and a range of leisure activities (e.g., club membership, religious services, painting, gardening) with the preservation of cognitive function.” A few small studies showed that “increased physical activity may help maintain or improve cognitive function in normal adults”.

I’ve written before about the extensive cognitive benefits of exercise, but as Noah Gray (via) says, “it never hurts to reinforce the message”.

Price Reductions and Cognitive Fluency

If the mental calculation required to determine the discount given on a product is difficult then we often misjudge the magnitude of the reduction.

This “ease-of-computation” effect for judging price reductions is obviously related to other recent studies looking at ‘cognitive fluency‘ and is another way to manipulate and be manipulated through product pricing.

Consumers’ judgements of the magnitude of numerical differences are influenced by the ease of mental computations. The results from a set of experiments show that ease of computation can affect judgments of the magnitude of price differences, discount magnitudes, and brand choices. […] For example, when presented with two pairs of numbers, participants incorrectly judged the magnitude of the difference to be smaller for pairs with difficult computations (e.g., 4.97 – 3.96, an arithmetic difference of 1.01) than for pairs with easy computations (e.g., 5.00 – 4.00, an arithmetic difference of 1.00).

via Barking Up the Wrong Tree