learning – GOLLYGEE!

A study of honeybees has shown that a lack of sleep impairs their ability to recall recent events. From Scientific American:

After characterizing how honeybees find their way home when released in a new location, the scientists captured and then released bees in unfamiliar territory some 600 meters from their hive. In addition to tracking how long the bees needed to return home, the researchers monitored bee sleep. Bees take brief naps throughout the day in addition to longer periods of nocturnal sleep. (Snoozing bees are easy to spot because their antennae droop.) The scientists made their observations both by watching bees in person and by tracking their activity via radio-frequency devices that they glued onto some of the insects.

The researchers verified first that finding a new route home did not alter other foraging behaviors, although it did lead to an increase in sleeping time in the first part of the night. Curious as to whether this change might reflect some learning or memory process, the team decided to see what happens when bee slumber is disturbed by selectively placing the insects in a box that was gently agitated for about eight hours, making it difficult for them to relax and get a good night’s sleep.

The next day the researchers found that sleepless bees and well-rested ones performed no differently when left to find their way home from a novel location. In other words, lack of sleep apparently did not inhibit the bees’ learning processes. “This suggests that there are forms of learning that seem to be totally independent of sleep,” Menzel says.

The scientists observed, however, a significant and obvious difference when bees were brought to the new spot for a second day. This time, bees that had slept well found their way home faster and fewer got lost along the way than on the previous day. That observation indicates that the well-rested bees had learned from their experience the day before. Drowsy bees, however, took about as long to return home on the second day as on the first, and were just as likely to get lost.

The study appears in the Journal of Experimental Biology.

Learning in your sleep.

Apparently we can learn simple responses while we are sleeping. Unfortunately we can’t pick up French from playing the audio recording overnight. From Ed Yong over at The Scientist:

Several groups have tested for advanced forms of learning during sleep, like picking up the links between pairs of words. All such experiments have failed. The only positive results came from studies showing that a very basic form of learning known as classical conditioning can occur in sleeping rats and infants, which begin to associate two stimuli—say, a tone and a puff of air—if they are presented together.

By contrast, Arzi’s experiments used a different technique called “trace conditioning,” where the tone and the smells are separated by more than a second. “This is considered a more advanced type of learning, and unlike classical conditioning, it depends on the hippocampus,” she said. “This is the type of learning associated with more complicated cognitive tasks, and therefore finding it in sleep is potentially important and novel.”

Arzi also took steps to ensure that her subjects were not inadvertently waking up. Throughout her study, a sleep technician monitored the volunteers’ brain activity and halted the experiment whenever they showed signs of rousing. All such trials were left out of the final analysis.

Arzi’s volunteers only learned a very simple response, and it is not clear if we can pick up more complex information while sleeping. “This does not imply that you can place your homework under the pillow and know it in the morning,” she said. “There will be clear limits on what we can learn in sleep, but I speculate that they will be beyond what we have demonstrated.”

GOLLYGEE!

Tag: learning

lack of sleep can effect memory

can you learn in your sleep?