The effects of left and right monocular viewing on hemispheric activation

ABSTRACT

Background/Objectives: Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing.

Method: High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes.

Results: There was a significantly less alpha power over the right hemisphere’s parietal-occipital area with left and binocular viewing than with right-eye monocular viewing.

Conclusions: The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

KEYWORDS:

• Alpha activity
• electroencephalography
• hemispheric arousal
• monocular viewing
• parasympathetic autonomic nervous system
• sympathetic autonomic nervous system

Acknowledgments

K.H., D.B., J.W., and M.D. conceived the experiment, C.W., J.M., and D.B. conducted the experiment, C.W. analyzed the results, and C.W. and K.H. drafted the manuscript. All authors reviewed the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by the State of Florida Memory Disorders Clinics; the US Department of Veterans Affairs Office of Research and Development; and the National Science Foundation (NSF) [grant number BCS-1439188].