Hello Pali friends,
In the article from Rhys-Davids'es dictionary this term is explained as:
Gaṇhati & Gaṇhāti
Meanings: to take, take up; take hold of; grasp, seize; assume; ...http://dsal.uchicago.edu/cgi-bin/philol ... :1074.pali
This spectrum of meanings does not include the meaning of this word in the context of perception.
Monier-Williams dictionary gives such meanings:
grah [RV. in a few passages only AV. &c.] or grabh [RV. rarely AV.], cl. 9. P. gṛbhṇāti gṛhṇā́ti (also Ā. gṛhṇīte, irreg. gṛhṇate MuṇḍUp. 3. pl. gṛbhṇate RV.
• to perceive (with the organs of sense or with mánas), observe, recognise RV. i, 139, 10 and 145, 2 VS. i, 18 ŚBr. xiv MuṇḍUp. ŚvetUp. &c
• to receive into the mind, apprehend, understand, learn Nal. R. Ragh. v, 59 Pañcat. i, 1, 23http://faculty.washington.edu/prem/mw/g.html
And the new Pali-English dictionary by Margaret Cone also gives:
5. receives into the mind, apprehends, learns; accepts (instuction or criticism); ...
gāhi(n), mfn. [S. grāhin], seizing, grasping; holding; taking, receiving; apprehending; ...
In the context of perception, thuis term means 'apprehends', 'becomes conscious of, through the senses', 'perceives'.