Tool Module: Your “Mental Stopwatch”
But this model, which treats duration estimates as something that the brain calculates independently, then adds to our other mental processes, has now been set aside in favour of other models in which the calculation of duration is intrinsically linked to the basic information coming from our sensory inputs. For example, researchers such as Warren H. Meck, of Duke University in North Carolina, have developed a new theory of the mental stopwatch, based on the detection of coinciding oscillations in neural activity.
Functional magnetic resonance imaging (fMRI) has played a major role in this research, by letting scientists more accurately observe the brain structures involved in estimating intervals and the chronological sequence in which these structures are activated. Through fMRI, it has been shown that when the brain performs an interval-estimation task, it is the basal ganglia that are activated first, and in particular the striatum, which has a population of richly interconnected neurons that receive signals from many other parts of the brain. The dendrites of these neurons are covered with 10 000 to 30 000 dendritic spines, each of which receives information from a different neuron located in another area of the brain. The striatum is one of the very few places in the brain where there is such a convergence of thousands of neurons on single neurons.
Functional magnetic resonance imaging (fMRI) has played a major role in this research, by letting scientists more accurately observe the brain structures involved in estimating intervals and the chronological sequence in which these structures are activated. Through fMRI, it has been shown that when the brain performs an interval-estimation task, it is the basal ganglia that are activated first, and in particular the striatum, which has a population of richly interconnected neurons that receive signals from many other parts of the brain. The dendrites of these neurons are covered with 10 000 to 30 000 dendritic spines, each of which receives information from a different neuron located in another area of the brain. The striatum is one of the very few places in the brain where there is such a convergence of thousands of neurons on single neurons.
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