New ideas emerge from the collaboration between the cortex and the hippocampus

May 15, 2007 11:13 GMT  ·  By

Could our dreams be useful in getting new ideas?

Researchers at Harvard Medical School believe that sleeping is the way the brain processes the amount of daily information? so the idea above makes sense.

It is known that sleep strengthens learning and memory.

A previous research at Harvard led by Matthew Walker discovered that a good night's sleep can improve movement skills, playing a piece of music, riding a bike, or throwing a ball to the basket. "The key to solving problems and generating new ideas involves how those facts are put together into a bigger picture, one we've not seen before", said Walker, from the Harvard-affiliated Beth Israel Deaconess Medical Center.

56 male and female volunteers, aged 18 to 30, were asked to watch not familiar oval images of colorful abstract patterns, in combinations of five pairs of eggs. The shapes were marked and the subjects had to learn which shape matched over another shape.

For example, shape A over B, B over C, C over D etc.

In fact, there was a hidden link amongst all five pairs together: they matched together a specific pattern on an imaginary chain. The subjects were tested in 3 groups: one after 20 minutes, the second after 12 hours, and the third had 24 hours. 50 % of those in the 12-hour group slept before the test, 50 % did not. Subjects with a good night's sleep scored best, those in the 20-minute group were the worst.

The 20-minute group did not understand the idea (of A over B, B over C, C over D etc.). "Those who processed the information offline [while sleeping] were able to make leaps of inferential judgment just by letting their brain have time to unconsciously mull things over," Walker says. "Our results strongly imply that sleep is actively engaged in the cognitive processing of our memories. Knowledge appears to expand both over time and with sleep", added co-author Jeffrey Ellenbogen, a sleep neurologist at Brigham.

Thus, students should rather sleep than cram all-night long when preparing for a final exam if they want to acquire the critical information. But what exactly happens in the brain when it mixes facts together in new ideas?

It seems that here the hippocampus nucleus is involved, which during sleep carries on a "conversation" with the thinking part of the brain, the cortex. "The new information ripples through the old, swims in the sea of our past life experiences. This process builds new links, new networks of connections that lead to new ideas, new big pictures we've never seen before", explained Walker.

Another question is: how many fact "eggs" can you put into the brain in one night and still come up with new thoughts? Interesting issues would be how do memories fade with age or how many get erased in case of Alzheimer's disease and how much dreaming is involved in this?

Studies have shown that memories are strengthened both during dreamless sleep (at the beginning of the night) and during dreaming (later in the sleep). New memories could shift from the hippocampus into the cortex during dreamless sleep. The mix of new and old memories could result in bizarre and novel pattern named dreams. "Is this the basis of creativity, the cauldron from which those lights-on-in-your-head happenings trigger big, new ideas?", Walker asks.