When the typical computer user clicks an average of 7,400 mouse clicks per week, it’s safe to say that this ubiquitous gadget has shaped our lifestyle quite a bit. But researchers have discovered that this repetitive, manual interaction with a computer also alters how our brains represent movement.

"Computers produce this problem that screens are of different sizes and mice have different [degrees of sensitivity]," study leader, Konrad Kording, explained in a statement. "We want to quickly learn about these so that we do not need to relearn all possible movements once we switch to a new computer. If you have broad generalization, then you need to move the mouse just once, and there you are calibrated."

The Current Biology study, which was a collaboration between Northwestern University and Peking University, compared Chinese migrant workers, who were familiar with using computers, to other migrant workers, who were of the same age and education but never used a computer before. Both groups quickly learned how to properly move a cursor on a screen in one specific direction simply by moving their hand, which they couldn’t see, across a tabletop — the hand itself was the mouse in this case.

While both groups performed equally well in learning how to move the cursor in one direction, a notable difference became apparent when the participants had to move the cursor towards various targets. Those with computer experience were more adept at applying what they learned previously towards the more complicated task, a feat known as “generalizing.”

When we learn certain visually guided movements, the authors explain in the study, we have to create a representation in our heads, which is akin to a kind of internal model. This representation strengthens as we get better at translating a visual cue to a corresponding movement, which also allows us to be quicker at learning other tasks that are similar in nature i.e., generalize.

But the researchers showed that the disadvantage of being completely naïve to a motor task was by no means a drawback that was carved in stone. They had a new set of people who had never used a computer play computer games that required intense use of a mouse two hours every day for two weeks. After this time period, these formerly naïve computer users generalized just as well as experienced users at the cursor-hand movement task.

"Our data revealed that generalization has to be learned, and we should not expect it to happen automatically," observed lead author, Kunlin Wei. "The big question in the clinic[al] setting is whether supervised rehabilitation can lead to functional improvement at home. Thus, the natural [next] step for us is to experiment on how to make this generalization from clinics to home happen more effectively." Kording added that future inpatients could benefit from robotic training that allowed them to generalize perfectly when taking on typical everyday tasks at home.

The observed impact that mouse clicking has on our ability to learn new motor tasks is comparable to a study that looked at the cognitive impact of the internet when it makes information a click away. People who don’t know an answer to a question nowadays can look it up on their phone, which primes them to think about ways to access information from an external source and lowers recall from memory.

Source: Wei K, Yan X, Kong G, et al. Computer Use Changes Generalization of Movement Learning. Current Biology. 2013.