What Driving in a New Place Tells Us About the Brain
Your brain is constantly learning.
When you’re just learning how to drive or you’re trying to navigate a new town, you really need to pay attention. You scan every street sign and make sure to signal your turns well in advance. You have no idea where you are, and you’re just looking for any sort of clue that might match up to half-assed directions. But then you make that drive a couple more times, and it’s almost automatic.
Thank your brain. Research published in the journal PLOS Biology on Tuesday describes exactly how your brain learns about a new place. By conducting brain scans on people who were asked to do a simple visual task twice a day for a month, researchers from University of California, San Diego learned that their participants really only needed to pay active attention to the task for the first two days before it became ingrained.
Once they got the hang of it, they stopped paying attention and other regions of their brain took over, but they still performed just as well as when they were focused.
When it comes to learning about a new place, it’s not that you simply got better at navigating through that area; your brain simply gets efficient in allocating resources.
It seems that instead of focusing on the task at hand, brains are actually working to filter out all of the background noise that might distract them from the task. Researchers used electroencephalography brain scans to record the brain’s electrical activity, the scientists found huge spikes of activity in the parts of the visual cortex that correspond to effortful focus on the task at hand. After about two days of repeating a task, the activity in the parts of the brain responsible for attention dropped off sharply, even though the participant’s ability to complete the experimental task did not.
What that means is that by the time you know how to drive a new route, your brain can basically get you there on autopilot. And the key way it does that is by keeping you from getting distracted by extraneous details along the way. Basically, instead of working to plan your route, your brain is working to keep everything else out.
The team of scientists was surprised by its findings — they expected active attention to play a much longer role throughout the study, and they expected it to be more closely linked to performance. That’s because previous studies like this have been conducted on primates, not people, and animal models often fail to generalize to human relevance. The researchers suspect that the difference between the groups is at least partially related to the fact that it can take months of focused training for a primate to learn a task that a human can figure out in a matter of minutes.
So while it might be unnerving to realize you’ve arrived at a destination and don’t remember how you got there in the first place That sort of automatic, mindless navigation is just fine — it’s just your brain letting you know that it’s got things under control.
Abstract: Selective attention supports the prioritized processing of relevant sensory information to facilitate goal-directed behavior. Studies in human subjects demonstrate that attentional gain of cortical responses can sufficiently account for attention-related improvements in behavior. On the other hand, studies using highly trained nonhuman primates suggest that reductions in neural noise can better explain attentional facilitation of behavior. Given the importance of selective information processing in nearly all domains of cognition, we sought to reconcile these competing accounts by testing the hypothesis that extensive behavioral training alters the neural mechanisms that support selective attention. We tested this hypothesis using electroencephalography (EEG) to measure stimulus-evoked visual responses from human subjects while they performed a selective spatial attention task over the course of ~1 month. Early in training, spatial attention led to an increase in the gain of stimulus evoked visual responses. Gain was apparent within ~100 ms of stimulus onset, and a quantitative model based on signal detection theory (SDT) successfully linked the magnitude of this gain modulation to attention-related improvements in behavior. However, after extensive training, this early attentional gain was eliminated even though there were still substantial attention-related improvements in behavior. Accordingly, the SDT-based model required noise reduction to account for the link between the stimulus-evoked visual responses and attentional modulations of behavior. These findings suggest that training can lead to fundamental changes in the way attention alters the early cortical responses that support selective information processing. Moreover, these data facilitate the translation of results across different species and across experimental procedures that employ different behavioral training regimes.
