to habituate = to accustom, to make used to

http://www.thefreedictionary.com/habituating

However. it is glabellar reflex and NOT 'gabellar reflex'

The glabellar reflex is elicited by repeatedly tapping the patient between the eyebrows (the glabella area), causing them to blink. Normally, the adult patient habituates to the stimulus, and ceases blinking after a few taps. If blinking persists, it is abnormal in adults.
http://link.springer.com/referenceworkentry/10.1007/978-0-38...

The glabellar tap reflex has been studied in 88 adults with mental retardation and 20 normal controls. None of the 20 controls had abnormal response to glabellar tap. All the subjects with mental retardation had abnormal response to glabellar tap, 80 subjects had 'no habituation' and eight subjects had 'poor habituation' of response to glabellar tap.
http://www.ncbi.nlm.nih.gov/pubmed/7169634

Habituation of the second component causes the glabella tap response to disappear ... and the second component fails to habituate (persistent glabella reflex”)
https://www.google.com/search?as_q=Gabella reflex habituatin... (page 165)