RT Journal Article
SR Electronic
T1 Microsaccades Are Coupled to Heartbeat
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 1237
OP 1241
DO 10.1523/JNEUROSCI.2211-15.2016
VO 36
IS 4
A1 Ohl, Sven
A1 Wohltat, Christian
A1 Kliegl, Reinhold
A1 Pollatos, Olga
A1 Engbert, Ralf
YR 2016
UL http://www.jneurosci.org/content/36/4/1237.abstract
AB During visual fixation, the eye generates microsaccades and slower components of fixational eye movements that are part of the visual processing strategy in humans. Here, we show that ongoing heartbeat is coupled to temporal rate variations in the generation of microsaccades. Using coregistration of eye recording and ECG in humans, we tested the hypothesis that microsaccade onsets are coupled to the relative phase of the R-R intervals in heartbeats. We observed significantly more microsaccades during the early phase after the R peak in the ECG. This form of coupling between heartbeat and eye movements was substantiated by the additional finding of a coupling between heart phase and motion activity in slow fixational eye movements; i.e., retinal image slip caused by physiological drift. Our findings therefore demonstrate a coupling of the oculomotor system and ongoing heartbeat, which provides further evidence for bodily influences on visuomotor functioning.SIGNIFICANCE STATEMENT In the present study, we show that microsaccades are coupled to heartbeat. Moreover, we revealed a strong modulation of slow eye movements around the R peak in the ECG. These results suggest that heartbeat as a basic physiological signal is related to statistical modulations of fixational eye movements, in particular, the generation of microsaccades. Therefore, our findings add a new perspective on the principles underlying the generation of fixational eye movements. Importantly, our study highlights the need to record eye movements when studying the influence of heartbeat in neuroscience to avoid misinterpretation of eye-movement-related artifacts as heart-evoked modulations of neural processing.