Brain Clocks: The Neuroscience of Time
Time is something we want more of, and want to do more with. Whether we like it or not, our brains are running multiple clocks that pace aging, wake us up, and control how quickly our muscles fire at the gym.
Time in the brain is most certainly unlike the time you remember from physics class. Brain Clocks explores the neuroscience of time using studies of high performance, as well as examining the bizarre and crippling effects that broken clocks have on the mind.
Left: A History of the Hemispheres
In the late nineteenth century a mild-mannered surgeon from Paris fostered a discovery that spurred a revolution. It spat in the face of the Church, upturned decades of intuitions, and was a turning point in the history of brain science. The two sides of our brains are different.
Left journeys through history to meet our tool-making ancestors, the first-ever serial killers, and modern-day scientists who have all partaken in the story of our asymmetric brains.
In 2016, we published a study on the role of ketamine in disrupting cortical information transfer. It continues to be critical for anesthesia, but is also gaining traction as a useful therapeutic for depression, and has historically been used to model schizophrenia. It’s a fascinating drug and nice to see positive, science-based applications.
All roads lead to mitochondria (it seems)—the “power house” of our cells. This paper suggests that DBS has a positive affect on mitochondrial volume in the brain region that houses dopamine cells. We know that DBS alters a number of physiologic parameters, and while it’s likely that changes in mitochondria are temporally downstream of the immediate therapeutic effects, it remains an interesting finding because of other theories regarding mitochondrial dysfunction and Parkinson’s disease.
Reinforcement learning (RL) suffers when tasks change. For example, RL does not have a built-in mechanism to switch between modes of exploitation and exploration, which is critical to mapping optimal rewards in a variable environment. Here, Dudman and Li show that mice—like humans—model rewards on highly flexible probability distributions.
Why are there errors in our decisions? Is it that noise gets into a perfect signal, or that decision machinery is inherently probabilistic? This paper argues the latter. From the perspective of optimal coding—where optimal means metabolically efficient—it offers a useful lens through which we can view modern findings in neuroscience and behavior research.
Mello et al. find that the majority of neurons encoding time in the striatum, a central basal ganglia structure, contract and dilate their firing based on the task interval. These results highlight how neural activity is translated into optimally timed motor actions.
Whether there is an underlying neural code that can explain information transfer in the brain has yet to be determined. This paper explores the idea that more neurons than we currently appreciate may live near dormancy and how those quasi-quiescent states contribute to computation in the brain.
Student Spotlight Interviews
Sharena Rice is fantastic. She is a punster-calligrapher-scientist. Her positively contagious personality and perspective on life might just make your day.
She’s a young woman whose story will make your heart beat just a little bit louder. Elizabeth Rodriguez is the rare amalgamation of motherly wisdom and youthful flare that is chicken soup for our souls.
Rafi Kohen is a Turkish delight, an infectious concoction of talent and personality. From tackling problems of synaptic plasticity during the day, to unleashing his tango at night, he’s a man you could enjoy tea and laughs with for days on end.
Kate is Midwest modesty and big city drive, all wrapped into one. Although she isn’t one to brag, she’s a classically trained musician—Vivaldi on the violin—not to mention Picasso with a pencil! This will be the last time you think of corn fields when you hear the word “Nebraska” because, if Kate’s smile hasn’t already won you over, her story will.
She is a tea-drinking, guitar-playing runner who believes that education is a right, not a privilege. She studies from a three-inch heap of notecards, daydreams about time travel, and, in high school, thought she would eventually become a quantum physicist. Ladies and gentlemen, Christina May is a huge force in a petite package, and she is impossible to forget!