Age differences in thalamic low-frequency fluctuations.

The thalamus plays a role in many different types of cognitive processes and is critical for communication between disparate cortical regions. Given its critical role in coordinating cognitive processes, it is important to understand how its function might be affected by aging. In the present study, we examined whether there are age differences in low-frequency fluctuations during rest in the thalamus. Across independent data sets, we found that the amplitude of low-frequency (0.01-0.10 Hz) oscillations was greater in the thalamus among older than younger adults. Breaking this low-frequency range down further revealed that this increase in amplitude with age in the thalamus was most pronounced at the low end of the frequency range (0.010-0.027 Hz), whereas in the higher low-frequency range (0.198-0.250 Hz) younger adults showed greater amplitude than older adults. These shifts in thalamic low-frequency oscillatory activity likely influence the complex dynamics of coordinated brain activity and influence cognitive performance.