By Neuroscience News
From the cosmic dance of stars to our heartbeat's rhythmic pulse, time is integral to existence. Its elusive nature has sparked curiosity among scientists and philosophers for centuries. Despite being a fundamental part of our daily experience, the perception of time remains a puzzle. This journey delves into our brains to explore a neural timepiece. A clock that shapes our perception of seconds and minutes.
The theory of relativity rocked the scientific world with a new perspective on time. Time could warp, stretch, and contract under different conditions, an idea known as time dilation. Just as the cosmos bends time, our brains can also warp our subjective experience of it. The seconds can drag in anticipation or fly in joy, painting unique temporal landscapes of our life.
A team of researchers at Champalimaud Research’s Learning Lab have been investigating the neural underpinnings of time perception. They propose a decentralized and flexible sense of time in our brains. Our brains rely on groups of neurons firing in consistent patterns, a concept they call the "population clock". It's similar to observing the predictable ripples created by a stone hitting water.
These researchers focused their studies on the striatum, a deep-seated brain region. The striatum displayed predictable patterns of neural activity that evolved at different speeds. This variability in speed was observed to correlate with the animals' judgement of time. A faster evolution of patterns was associated with a perception of longer time intervals.
To ascertain whether the striatum was just correlating or directly influencing time perception, they applied an ingenious technique. Using a custom thermoelectric device, they warmed or cooled the striatum of rats. Cooling slowed the neural activity, making rats perceive a given time interval as shorter. Warming sped up activity, and rats perceived the interval as longer.
Interestingly, manipulating the striatum's neural activity did not alter the animals' movements in the task. This suggested that the striatum might not be involved in continuous motor control but more in determining 'what' to do and 'when'. The precise execution of the action was hypothesized to be controlled by other brain structures.
These findings can provide significant insights into neurological disorders like Parkinson's and cerebellar ataxia. Parkinson's patients, who often have a compromised striatum, struggle with initiating motor plans. On the other hand, patients with cerebellar damage can initiate movements but struggle with their execution.
By dissecting the causal relationship between neural activity and timing function, this research opens new avenues for therapeutic interventions. Diseases involving time-related symptoms and a compromised striatum, such as Parkinson's and Huntington's, could benefit from these findings. As we continue to explore the mysteries of time, one thing is certain - our brains are intricate, fascinating, and full of surprises.