It seems like everyone is always multi-tasking these days, even in the midst of conversation with loved ones. For example, how often have you seen people eating dinner with family and friends while checking their email or the latest football scores on their smartphones? I see it too often. Well, other than not paying attention to your loved ones, you may be hindering communication in another way. A study recently published in the Journal of Experimental Psychology: General (here), shows that when you occupy the part of your brain that enacts gestures (the motor cortex associated with the hands and arms), you also inhibit the understanding of someone else’s gestures.
In a two-part study, Raedy M. Ping, Susan Goldin-Meadow, and Sian L. Beilock first verified that people use a speaker’s gestures to understand what the speaker is saying. Importantly, in the second part, they found that keeping people’s hands busy makes them less able to use a speaker’s gestures to understand what the speaker is saying.
To begin with, people saw video clips of a speaker uttering sentences. After each sentence, a picture was shown. The participants had to answer ‘yes’ or ‘no’ after each sentence depending on whether or not the item in the picture was mentioned in the sentence that was just said. Sometimes the speaker in the video gestured in a way that was congruent with the picture and sometimes they gestured in a way that was incongruent with the picture. For example, a participant could have been shown a video of a person saying “The man wrote down my phone number with a pencil,” while gesturing that they were writing on a wall. If the participant saw a picture of a pencil, but it was pointing down (as if someone was writing on a table), then the gesture would be incongruent with the picture even though the participant should still respond ‘yes’, because they were told to respond regardless of how the item was presented. (There were also times when the picture did not match the item mentioned in the sentence, but those weren’t analyzed).
The researchers found that it took people longer to correctly identify an item, like a pencil, as being in a sentence, when the gesture was incongruent with the picture they were seeing than when it was congruent. What does this mean? This means that people are taking in the information from the gesture to understand what the speaker is saying and when the gesture (and what they understand) matches how the item is presented, they are able to understand the message faster than when it doesn’t match.
Now for the more interesting part. Ping, Goldin-Meadow, and Beilock wanted to know if this ‘advantage’ of using gestures to understand would go away when someone’s hands were occupied. They repeated a similar task, except for the second part of the study participants had to simultaneously listen to sentences with gestures and perform a motor task. You might think, “Well, your attention is split, so of course your comprehension will suffer.” Well, they had half of the participants perform a motor task with their hands and half of the participants had to perform a motor task with their feet, both task involving additional attention. If a listener’s motor cortex is involved in understanding someone’s gestures, and therefore, their message, this should only apply to the part of the motor cortex dedicated to hands and arms where gesturing is done.
When people had to make motor movements with their feet, they still were able to answer faster when a sentence and a picture were congruent, meaning their motor cortices associated with gestures were still helping them comprehend. When people had to make motor movements with their hands, on the other hand, there was no longer an advantage to seeing congruent gestures and pictures.
What does this all mean? When the part of a person’s motor cortex associated with gesturing is being used for something else, like playing games on his or her phone, that part of the cortex is not as able to help one understand someone else's gestures, which are important to communication.
Conclusions: get off your phones! Your relationships will thank you.