Pupil diameter fluctuation throughout the respiratory cycle is autonomically controlled in the resting state, as pupils dilate during inspiration and constrict during expiration. Furthermore, pupil size is differentially modulated by cognitive states between task engagement and disengagement. To determine whether respiratory-dependent fluctuations in pupil size are maintained during a cognitive task, we employed healthy human subjects performing a delayed matching-to-sample task with a short delay and measured their pupil sizes and R wave-to-R wave intervals (RRIs). We detected respiratory fluctuations in pupil size and the RRI during the delay period immediately before the discrimination stage of the task. During the discrimination stage, the cognitive state with the higher task engagement yielded more pupil dilation. However, respiratory fluctuations in pupil size were abolished, whereas those in the RRI were still discernible during the discrimination stage. Our results suggest that an alternative control mechanism involving the cognitive state associated with task engagement overrides the respiratory-related autonomic control of pupil diameter.
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http://dx.doi.org/10.1016/j.resp.2018.07.005 | DOI Listing |
eNeuro
January 2025
Cognitive Psychology Unit, Faculty of Social Sciences, Leiden University, Wassenaarseweg 52 2333 AK, Leiden, Netherlands.
The brain attends to environmental rhythms by aligning the phase of internal oscillations. However, the factors underlying fluctuations in the strength of this phase entrainment remain largely unknown. In the present study we examined whether the strength of low-frequency EEG phase entrainment to rhythmic stimulus sequences varied with pupil size and posterior alpha-band power, thought to reflect arousal level and excitability of posterior cortical brain areas, respectively.
View Article and Find Full Text PDFPsychophysiology
January 2025
Department of Psychology, Hangzhou Normal University, Hangzhou, Zhejiang, China.
The aperiodic exponent of the power spectrum of signals in several neuroimaging modalities has been found to be related to the excitation/inhibition balance of the neural system. Leveraging the rich temporal dynamics of resting-state pupil fluctuations, the present study investigated the association between the aperiodic exponent of pupil fluctuations and the neural excitation/inhibition balance in attentional processing. In separate phases, we recorded participants' pupil size during resting state and assessed their attentional orienting using the Posner cueing tasks with different cue validities (i.
View Article and Find Full Text PDFNature
January 2025
Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA.
Recently acquired memories are reactivated in the hippocampus during sleep, an initial step for their consolidation. This process is concomitant with the hippocampal reactivation of previous memories, posing the problem of how to prevent interference between older and recent, initially labile, memory traces. Theoretical work has suggested that consolidating multiple memories while minimizing interference can be achieved by randomly interleaving their reactivation.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Neurosurgery, Baylor College of Medicine, Houston, USA.
Alteration of responses to salient stimuli occurs in a wide range of brain disorders and may be rooted in pathophysiological brain state dynamics. Specifically, tonic and phasic modes of activity in the reticular activating system (RAS) influence, and are influenced by, salient stimuli, respectively. The RAS influences the spectral characteristics of activity in the neocortex, shifting the balance between low- and high-frequency fluctuations.
View Article and Find Full Text PDFBehav Res Methods
December 2024
Section on Functional Imaging Methods, Laboratory of Brain and Cognition, National Institute of Mental Health (NIMH), National Institutes of Health (NIH), NIHBC 10 - Clinical Center BG RM 1D80, 10 Center Dr., Bethesda, MD, 20892, USA.
Pupillometry is a popular method because pupil size is easily measured and sensitive to central neural activity linked to behavior, cognition, emotion, and perception. Currently, there is no method for online monitoring phases of pupil size fluctuation. We introduce rtPupilPhase-an open-source software that automatically detects trends in pupil size in real time.
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