Non-directional transient cells

The code simulates magnocellular cells in Retina and lateral geniculate nucleus.

This software has been realized by Praveen Pilly at the CNS Technology Lab at Boston University (http://techlab.bu.edu/).

Attached is the source article and zipped file that contains a MATLAB-based graphical user interface with additional access to the non-directional transient cell equation, description, and source code.

Reference
Grossberg, S. , Rudd, M.E., Cortical dynamics of visual motion perception: Short-range and long-range apparent motion, Psychological Review , 99 , 78-121 (1992).

Abstract
The microcircuit for non-directional transient cells simulates how magnocellular cells in Retina and lateral geniculate nucleus are activated in response to temporal changes in the visual stimulus. This acts as the first stage of various motion processing models (Chey et al., 1997; Grossberg et al., 2001; Berzhanskaya et al., 2007; Grossberg & Pilly, 2008). Two kinds of these magnocellular cells, ON and OFF, give transient responses to bright stimulus onset and offset or dark stimulus offset and onset, respectively (Baloch et al., 1999; Schiller, 1992). These transient responses are sensitive to the contrast of the moving dots but not to the duration for which stimulus stays on or off beyond a critical duration (see Figure 2 in Grossberg & Pilly, 2008). ON and OFF transient cells code the leading and trailing edges, respectively, of a moving bright object (Schiller, 1992). Modeling the cross talk between ON and OFF cells is important to simulate direction judgments of contrast polarity-reversing or reverse-phi motion stimuli (Anstis, 1970; Anstis & Rogers, 1975; Baloch et al., 1999; Chubb & Sperling, 1989).