Affiliations: School of Psychology, Bangor University, Bangor,
UK | Center for Mind/Brain Sciences (CIMeC), University of
Trento, Rovereto, Italy
Note: [] Corresponding author: Martijn van Koningsbruggen, School of
Psychology, Bangor University, Bangor, LL57 2 AS, UK. Tel.: +44 (0) 1248
358554; E-mail: pss801@bangor.ac.uk
Abstract: The current paper describes a rare case of a patient who suffered
from unilateral apraxia of eye closure as a result of a bilateral stroke.
Interestingly, the patient's ability to voluntarily close both eyelids (i.e.
blinking) was not affected, indicating that different neural mechanisms control
each type of eye closure. The stroke caused damage to a large part of the right
frontal cortex, including the motor cortex, pre-motor cortex and the frontal
eye field (FEF). The lesion in the left hemisphere was restricted to the FEF.
In order to further study the neural mechanisms of eye closure, we conducted an
fMRI study in a group of neurological healthy subjects. We found that all areas
of the oculomotor cortex were activated by both left and right winking,
including the FEF, supplementary eye field (SEF), and posterior parietal cortex
(PPC). Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were
significantly more active during winking than blinking. Together, these results
provide evidence for a critical role of the FEF in voluntary unilateral eye
closure.
