Title :
Outputs of paired Gabor filters summed across the background frame of reference predict the direction of movement (vision)
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
A cortical neural network that computes the visibility of shifts in the direction of movement is proposed. The network computes: (1) the magnitude of the position difference between the test and background patterns, (2) localized contrast differences at different spatial scales analyzed by computing temporal gradients of the difference and sum of the outputs of paired even- and odd-symmetric bandpass filters convolved with the input pattern, and (3) using global processes that pool the output from paired even- and odd-symmetric simple and complex cells across the spatial extent of the background frame of reference the direction a test pattern moved relative to a textured background. Evidence that magnocellular pathways are used to discriminate the direction of movement is presented. Since magnocellular pathways are used to discriminate the direction of movement, this task is not affected by small pattern changes such as jitter, short presentations, blurring, and different backgrounds contrasts that result when the veiling illumination in a scene changes.
Keywords :
neural nets; vision; background contrast; background frame of reference; bandpass filters; blurring; complex cells; cortical neural network; jitter; magnocellular pathways; movement direction prediction; paired Gabor filters; short presentation; simple cells; spatial scales; temporal gradients; veiling illumination; Computer networks; Frequency; Gabor filters; Gratings; Image motion analysis; Navigation; Optical filters; Pattern analysis; Space technology; Testing; Artificial Intelligence; Humans; Mathematical Computing; Models, Neurological; Motion Perception; Nerve Net;
Journal_Title :
Biomedical Engineering, IEEE Transactions on