Category: Cognition (page 2 of 3)

sleeping enhances memory more in children than adults

Sleeping child

Sleeping seems to enhance memory moreso for kids than adults. In a study children were able to turn implicit knowledge in to explicit knowledge at a higher rate than adults after 10-12 hours of sleep.

Popular Science offers this blurb on a study from Nature Neuroscience:

As a child, you sleep more deeply than an adult, and experience three times more slow-wave sleep and higher electrical activity in the brain during that sleep. This may help turn the large amount of information you accumulate during the day into knowledge you can recall intentionally.

The study, published in Nature Neuroscience this week, looked at 35 children between 8 and 11 years old, as well as 37 adults between 18 and 35. They were each asked to quickly press a sequence of buttons after they lit up. Half of them performed the activity before sleep, and half after. They were then asked to recall the sequence of the eight lights 10 to 12 hours later.

After sleeping, almost all of the children turned the implicit knowledge into explicitly and could remember the sequence they had pressed perfectly, while adults experienced smaller gains. Both groups remembered the sequence better after sleep than those who were asked to recall it right after their training.

rat brain telepathy

One rat brain can control the decisions of another using a brain-to-brain interface. The brain activity of one rat is encoded and then transmitted to the matching area of another. The rat receiving the signal will usually perform in the same manner. Ed Yong describes the intercontinental telepathy in Nature News:

The brains of two rats on different continents have been made to act in tandem. When the first, in Brazil, uses its whiskers to choose between two stimuli, an implant records its brain activity and signals to a similar device in the brain of a rat in the United States. The US rat then usually makes the same choice on the same task.

Miguel Nicolelis, a neuroscientist at Duke University in Durham, North Carolina, says that this system allows one rat to use the senses of another, incorporating information from its far-away partner into its own representation of the world. “It’s not telepathy. It’s not the Borg,” he says. “But we created a new central nervous system made of two brains.”

The original research is reported in Scientific Reports.

thinking is harder in the heat

SciAm profiles a series of studies on temperature and cognition. Researchers at the University of Virginia and the University of Houston tested and compared decision making skills at warm and cooler temperatures. They found significant performance drop-offs when participants were kept at warmer temperatures. Excerpt:

The researchers decided to test this apparent link between weather and complex decision-making in the lab by performing a series of experiments comparing participants’ cognitive performance at two seemingly unremarkable temperatures: 67° and 77° Fahrenheit. People tend to be most comfortable at around 72° Fahrenheit, so each temperature represented just a 5° deviation from maximum comfort.

Despite this minimal deviation in temperature, the researchers found remarkable differences in cognitive functioning. In one lab study, participants were asked to proofread an article while they were in either a warm (77°) or a cool (67°) room. Participants in warm rooms performed significantly worse than those in cool rooms, failing to identify almost half of the spelling and grammatical errors (those in cool rooms, on the hand, only missed a quarter of the mistakes). These results suggest that even simple cognitive tasks can be adversely affected by excessive ambient warmth.

In a second study, the researchers showed similar effects for more complex cognitive calculations. In this study, another group of participants were asked to choose between two cell phone plans, again in either a warm or a cool room. One plan looked more attractive on the surface, but was actually more expensive; simple patterns of decision-making would therefore lead participants to choose the more expensive plan, whereas more complex analyses would lead participants to correctly choose the more cost-effective plan. Participants in the cool room made the correct choice over half the time; those in the warm room, on the other hand, made the correct choice only a quarter of the time. Warmer temperatures seemed to make participants more likely to rely on simplistic patterns of decision-making, which in turn led to inferior choices. These results suggest that complex decision-making, like simple cognitive tasks, is adversely affected by warm temperatures.

More at the link, including summary of a third study.