Respects to all,
According to Maha Periyava, in Deivathin Kural, Pillaiyar is the only God who does not need a temple, He is happy by the street side. He is also Vamana Roopa (small in size) , Maha Kaya (big in size) as in Vakra thunda Maha kaya, the One who has no origin, (He was present -saakshaat ) during the marriage of Siva and Parvati.
Also Pillaiyar has different forms and colors in different yugas, with Dhoomakethu (like air) very soon. Agasthiyar temple in T Nagar Madras has pillars with Pillaiyar's different forms in different yugas.
So the analogy with human brain does not rhyme with Maha Periyava's views.
Vish Iyer MS FRCS