Teller's initial research studies were focused on the spatial and temporal properties of a phenomenon first described by Professor Gerald Westheimer and sometimes referred to as the “Westheimer effect”[6] or the “Westheimer function.”[7] In this phenomenon, which Teller termed “spatial sensitization,” the detectability of a test light is first decreased and then increased by adding light to successively larger surrounding or annular regions. Westheimer proposed that the increase in detectability with surround illumination might represent the manifestation of lateral inhibition within the retina,[8] and this possibility motivated Teller's interest in the phenomenon.