|Dan-Anders Jirenhed and Anders Rasmussen.|
It has long been known that both animals and humans, through a type of learning known as eyeblink conditioning, can learn to blink in response to a tone with a precision of some tens of milliseconds. Previous studies have shown that eyeblink conditioning is dependent on the cerebellum and, so far, it has been assumed that the precise timing is completely automatic.
When researchers Anders Rasmussen and Dan-Anders Jirenhed performed laboratory studies as part of their teaching at the medical programme at Lund University, they discovered that the theory was incorrect in practice.
Rasmussen and Jirenhed tested 21 medical students at Lund University and could see that the students were able to control the exact timing of their blinking with unexpected accuracy. The researchers' results, now published in Scientific Reports, question whether previous studies on human eyeblink conditioning have, in fact, studied purely automated learning or if the test subjects also voluntarily controlled their their blinking.
"Our results are an important step in understanding how the human brain can control the timing of our movements -- and to what extent we can influence them at will," says Anders Rasmussen.
The fact that the movements can be controlled at will also shows that the cerebral cortex, perhaps through cooperation with the cerebellum, can play an important role in terms of timing.
Read more at Science Daily