Purchase this article with an account.
Bo Cao, Arash Yazdanbakhsh, Ennio Mingolla; Brightness-related responses in V1 and V2, a computational model. Journal of Vision 2011;11(11):364. doi: 10.1167/11.11.364.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Brightness information can be in part encoded in monkey V1 and V2 (Friedman et al., 2003, Journal of Physiology London; Roe et al., 2005, PNAS; Rossi et al., 1996, Science; Rossi & Paradiso, 1999, Journal of Neuroscience). Some V1 neurons show responses that track the temporal profile of luminance change of surrounding areas that are several degrees away from the cells' receptive fields, while the luminance of the area that covers the receptive fields stays constant (Rossi et al., 1996, Science). The response of such neurons in monkeys seems correlated with the perception of simultaneous contrast in humans. However, V1 neurons do not respond to other stimuli that generate induced brightness in humans, such as the Craik-O'brien-Cornsweet effect (COCE). Interestingly, some V2 neurons' activities are modulated by temporal variations in COCE luminance profiles (Roe et al., 2005, PNAS). Our neural model of functional connections in V1 and V2 simulates reported cell responses to both simultaneous contrast and the COCE. Although the model's recurrent connections within V1 and feedback connections from V2 may handle the “simultaneous contrast” response in V1, they cannot support appropriate modulation of activity in V2 corresponding to the center of a COCE-like stimulus without the additional mechanism inspired by the work of Ts'o and Roe (1999, Journal of Physiology) and Ts'o et al. (1986, Journal of Neuroscience). Certain model V1 neurons send information from luminance edges to model V2 neurons whose receptive fields do not overlap those of the projecting V1 neurons. This type of connection enables the V2 neurons to modulate their response according to contextual information from edges and surrounding areas, as occurs in brightness induction (e.g., the COCE). The model provides an alternative to diffusion-like filling-in and may shed light on possible mechanisms underlying spatio-temporal properties of brightness-related response in V1 and V2.
This PDF is available to Subscribers Only