Active sampling in visual search is coupled to the cardiac cycle

Abstract

Recent research has demonstrated that perception and reasoning vary according to the phase of internal bodily signals such as heartbeat. This has been shown by locking the presentation of sensory events to distinct phases of the cardiac cycle. However, task-relevant information is not usually encountered in such a phase-locked manner nor passively accessed, but rather actively sampled at one's own pace. Moreover, if the phase of the cardiac cycle is an important modulator of perception and cognition, as previously proposed, then the way in which we actively sample the world should be similarly modulated by the phase of the cardiac cycle. Here we tested this by coregistration of eye movements and heartbeat signals while participants freely compared differences between two visual arrays. Across three different analyses, we found a significant coupling of saccades, subsequent fixations, and blinks with the cardiac cycle. More eye movements were generated during the systolic phase of the cardiac cycle, which has been reported as the period of maximal effect of the baroreceptors' activity upon cognition. Conversely, more fixations were found during the diastole phase (quiescent baroreceptors). Lastly, more blinks were generated in the later period of the cardiac cycle. These results suggest that interoceptive and exteroceptive processing do adjust to each other; in our case, by sampling the outer environment during quiescent periods of the inner organism.

Behavioral and neurophysiological signatures of interoceptive enhancements following vagus nerve stimulation

“…Regardless of the phase and group, participants did press with similar latency to the R-peak (see also Galvez-Pol et al, 2020;Kunzendorf et al, 2019;Ohl et al, 2016). This means that nVNS might not improve interoceptive processing at the precision level, despite influencing overall accuracy.…”

“…Circular statistics were employed to analyze the temporal distribution of the key presses (Galvez-Pol, McConnell, & Kilner, 2020;Kunzendorf et al, 2019;Ohl, Wohltat, Kliegl, Pollatos, & Engbert, 2016). For each motor response within an epoch, we calculated the temporal distance to the preceding R-peak.…”

Respiration aligns perception with neural excitability

“…While the concept of active sensing has thus been well established in animals ( Wachowiak, 2011 ), interoceptive inference in human sensation is still in its infancy. Intriguingly, theoretical modelling work ( Allen et al, 2019a ; Corcoran et al, 2018 ; Owens et al, 2018 ) as well as empirical studies on various interoceptive signals ( Galvez-Pol et al, 2020 ; Mather and Thayer, 2018 ; Rebollo et al, 2018 ) are seeking to widen our understanding of how sampling information from the external world is coordinated with bodily states. Reports on functional body-brain coupling span cyclic signals from infraslow gastric ( Rebollo et al, 2018 ) over respiratory ( Herrero et al, 2018 ; Kluger and Gross, 2021 ) to cardiac rhythms ( Galvez-Pol et al, 2020 ; Mather and Thayer, 2018 ), showing that, across all time scales, sensory information is critically dependent on physiological rhythms.…”

“…Intriguingly, theoretical modelling work ( Allen et al, 2019a ; Corcoran et al, 2018 ; Owens et al, 2018 ) as well as empirical studies on various interoceptive signals ( Galvez-Pol et al, 2020 ; Mather and Thayer, 2018 ; Rebollo et al, 2018 ) are seeking to widen our understanding of how sampling information from the external world is coordinated with bodily states. Reports on functional body-brain coupling span cyclic signals from infraslow gastric ( Rebollo et al, 2018 ) over respiratory ( Herrero et al, 2018 ; Kluger and Gross, 2021 ) to cardiac rhythms ( Galvez-Pol et al, 2020 ; Mather and Thayer, 2018 ), showing that, across all time scales, sensory information is critically dependent on physiological rhythms. From a predictive processing perspective, the link between interoceptive and neural rhythms serves predictive timing , meaning that information sampling itself is temporally aligned with particular bodily states.…”

Relationship between cardiac cycle and the timing of actions during action execution and observation

“…Additionally, it is possible that as agents, we act upon the environment such that relevant signals appear during optimal phases of the cardiac cycle ( Galvez-Pol et al, 2020 ; Kunzendorf et al, 2019 ). It may be that stimuli whose processing would benefit from information on the state of cardiovascular arousal are more acutely perceived at systole, when baroreceptor feedback occurs, while stimuli that would not benefit from such signalling are better processed during diastole.…”