You might not be the only one who getting tongue-tied around other people. According to a new study, adults who typically stutter actually speak perfectly when they’re alone.
How do you figure out what someone does when they’re alone?
It’s not easy, because the second you bring someone into the lab to study them, they are, by definition, not alone. Because of this, past experiments have struggled to assess how individuals who stutter speak when they think nobody is listening. Thankfully, scientist have a super sophisticated technique they can use in situations like these. It’s called lying.
The experiment: Individuals who stutter were recruited to participate in an experiment. After making some polite conversation, the scientists asked the participant to solve a computer programming task. As the researchers got up to exit the room, they mentioned the fact that working through the task out loud can make it easier to solve. Then, they left and let the participant think they were all alone.
What happened next?
The scientists continued to observe the participants through cameras placed around the room. Several of the participants opted to talk out loud as they tried to solve the task in front of them. Amazingly, almost none of the participants stuttered at all while talking to themselves.
That’s cool, but lying still seems wrong.
Don’t worry – the scientists came clean once the study was over and gave the participants a chance to destroy the data if they didn’t appreciate the lies (turns out they were all super cool about it). On the plus side, now we know something pretty interesting about how stutters might emerge.
The Leak: When adults who typically stutter are left alone to speak to themselves, their stutter disappears. This suggests that stuttering might not be a limitation of one’s ability to produce speech, but rather the result of social pressure. So be patient with one another – we’re all friends here.
If you’re like us, you can sleep through your morning alarm, but not a crying baby on a flight. Why are we so easily woken by some stimuli but not others? To answer this question, a group of scientists carried out an experiment showing that like people, flies wake up more easily when exposed to specific stimuli.
How do you wake up a sleeping fly?
The researchers built an air puff robot to blow scents onto flies as they slept. It sounds ridiculous, but this contraption allowed them to systematically wake up the flies using finely controlled odor puffs. They then set up a few different conditions to see when the flies would wake.
The experiment: Once the flies were asleep, the scientists puffed them with a vapor of acetic acid (the main ingredient of vinegar). Being certified vinegar lovers, the flies were easily awakened by the acetic acid puffs. Next, the scientists got the flies drunk on ethanol, and then tried waking them once again. This time, they slept right through the entire experiment (who knew flies were so relatable??) Lastly, the scientists took away the flies’ food so that they got hungry, and then tried waking them up with a variety of different food-related and non-food-related odor puffs. These starved flies were more likely to be woken up by the food-related odors compared to non-food-related ones. It was as if their hunger made the food smells much more salient, even while they slept.
How does this work in the brain?
The scientists were able to pinpoint specific neurons in the fly brain that influenced when the flies would wake up. If you’re curious about the finer details, you can check out the full paper here.
The Leak: You aren’t the only one who wakes up for some disturbances but not others – flies are the same way. This paper suggests that internal states (like being hungry or drunk) appear to heavily impact this phenomenon. All this brings us one step closer to understanding the neural bases for why only some stimuli break through as we enjoy our Zzz’s.
Have you ever tried to learn a new sport but keep feeling like a klutz? Worry not – scientists in the field of motor control (think, the study of how we move) are hot on the case, trying to figure out how the brain learns new movement patterns. Why? For things like rehabilitation, but also to understand how we might be able to learn new skills quicker.
Learning quicker? Tell me more…
In this recent paper (free preprint), researchers hypothesized that since correcting for errors takes time and energy, the extent of an error might affect how quickly we learn from it. How did they prove this this? By showing people moving dots (seriously, get ready to read the word “dots” a hundred times in this next paragraph.)
The experiment: The researchers asked human participants to find a small patch of moving dots on a screen. Once they had located the patch and were looking at it, the participants had to figure out which direction the dots were moving in. On some trials, the dots all moved in the same direction, making the decision super easy. On others, the direction of the dots’ movement was rather inconsistent which made it hard to come up with a judgement. This meant that the more time people took to find the dots, the less time they had to take it all in and figure out the direction of the dots’ motion.
So what did they find?
Surprisingly, people became more efficient with their eye movements and arrived at the dot patch quicker on trials where the dots moved incoherently. It was as if the brain realized that the cost of losing time was greater on those trials and adapted to a more efficient pattern of eye movements to compensate.
The Leak: Learning a new movement pattern or skill takes practice, and mistakes can be frustrating. But this paper (preprint) shows that when the cost of a making an error is high, your brain adapts quicker. So maybe falling off your bike a few times while learning might not be so bad in the long run.
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