Afraid of the dark? Airplanes make your palms sweat? Forget about anxiety-reducing drugs. Relief from fear is at your fingertips—tickling. According to a new study published in the journal Neuroscience Letters
tickling makes fear go away, in rats at least.
That’s the second surprising thing I learned from this research. Rats are ticklish, apparently. Moreover, rats laugh. You’ve never heard them chuckling because rats laugh at ultrasonic frequencies, but the researchers used sophisticated eaves dropping equipment to catch rats vocalizing with glee when the scientists tickled the rodent’s tummies.
But let’s back up a minute. Reducing fear and anxiety is serious business. Hoards of folks take medicines to dampen their fears. Wouldn’t it be nice to have a way to accomplish the same objective without drugs?
This team of researchers from Japan was struck by evidence from many different studies suggesting that a positive outlook on life can relieve many ills and speed recovery from disease. Their previous research had even shown that tickling rats stimulated the birth of new neurons in the hippocampus, a part of the brain important for learning and memory.
So they tickled rats daily, Monday through Friday (presumably because they were performing other experiments on the weekend) for two weeks. Then they scared the heck out of the critters by putting them in an electrified cage and zapping them with a mild jolt of electricity right after sounding an alarm. The rats quickly learned that the alarm meant that they were about to be shocked, and so they froze in their tracks as soon as they heard it in subsequent tests. This is a well-established model of fear conditioning used to study learning and medical conditions such as post-traumatic stress disorder. But as time goes by, the rats tend to forget the bad experience and when they are returned to the cage a day or two later, the rats are not so quick to freeze when the tone sounds. In essence, with the passage of time they forgot their fear.
What the researchers found was that the group of rats that had been tickled for ten days before the fearful experience, forgot about the fact that the tone meant that they were about to be shocked much faster than rats that had not been tickled. Tickling put the bad experience behind them much faster.
The researchers also took blood samples and found biochemical evidence that the rats that had been tickled were less afraid. The amount of adrenaline in their bloodstream was much lower after fear conditioning than in animals that had not been tickled.
“Tickled animals may be a useful model to elucidate the underlying mechanisms how high expressions of positive emotions increase rates of recovery from acute and chronic disease,” the researchers conclude. This study provides more evidence of the power of positive thinking and possibly illuminates a new practical use for tickling apart from tormenting sibling.
Hori., et al, (2013) Effects of repeated tickling on conditioned fear and hormonal responses in socially isolated rats. Neuroscience Letters, on-line in advance of print.