Imagine yourself deep in a conversation in a quaint cafe, just about to make your most crucial and powerful point, and then “CRASH!” a waiter across the room drops a glass, it’s shards flying in every direction. Once the disruption has cleared, you turn back to your friend, take a deep breath, and then nothing…. What were you even talking about? Can you even remember the topic at all, much less your award-winning argument? Unfortunately you have just fallen victim to the classic “I just lost my train of thought.” What causes that total mind erasure though? A recent article published in Neuroscience News brings the findings of Jan Wessel, a post doctorate at University of California San Diego, about this bizarre phenomenon to light (Lost Your Train of Thought? Brain’s ‘Stopping’ System May Be to Blame, 2016).

There is an intrinsic system in humans that halts movement to avoid potential threats (Wessel et al., 2016). Imagine you’re about to cross the street after looking both ways, but just before stepping onto the pavement a car speeds around the corner. Your entire body freezes in response until the car passes and the street is once again clear. It has previously been shown that the sub thalamic nucleus (STN) is heavily involved in this process, and so this study by Wessel aimed to link activity in this region to cognitive disruption (Wessel et al., 2016). Volunteers’ capability to remember and recall a string of letters was tested while listening to a single frequency tone. On a few random trials, the tone was replaced with a bird chirping, which although it wasn’t a startling sound, it was still unexpected (Lost Your Train of Thought?, 2016). The results showed brain activation within the STN during these few trials and also interestingly enough, the greater the activation in this region, the greater the impairment in the subjects’ ability to recall the letters (Wessel et al., 2016).

What implications does this linkage have and why might further investigation be worthwhile? It is possible that the relationship might provide insight into distractibility in disorders like ADHD, or if the system could be manipulated to provide therapy for the unwanted thoughts of those that suffer from PTSD (Wessel et al., 2016). Another interesting relationship is that the STN is the part of brain that receives stimulation in Parkinson’s patients as a form of therapy (Lost Your Train of Thought?, 2016). People who suffer from Parkinson’s are sometimes described as hard to distract, or overly focused on what they are saying (Lost Your Train of Thought?, 2016). If it is true that cognition control is linked to movement control by the STN, other therapies for Parkinson’s patients could be developed. A correlation between these two different brain systems seems apparent but further research is definitely necessary to support a definitive linkage.

References

Lost Your Train of Thought? Brain’s ‘Stopping’ System May Be to Blame. (2016, April 18). Retrieved April 20, 2016, from http://neurosciencenews.com/stn-neuroscience-psychology-4075/

Wessel, J. R., Jenkinson, N., Brittain, J., Voets, S. H., Aziz, T. Z., & Aron, A. R. (2016). Surprise disrupts cognition via a fronto-basal ganglia suppressive mechanism. Nature Communications Nat Comms, 7, 11195. doi:10.1038/ncomms11195