function result = facilitation(matrix, facilterm, sigma, beta, f1, f2, orientation, power) % VERSION 21/03/04 % CREATED BY: M.B. Wieling and N. Petkov, Groningen University, % Department of Computer Science, Intelligent Systems % % FACILITATION: applies surround facilitation to the MATRIX according to the other % parameters. % FACILITATION(MATRIX, FACILTERM, SIGMA, BETA, F1, F2, ORIENTATION, POWER) with the following parameters % MATRIX - the matrix to which surround facilitation should be applied % FACILTERM - the matrix which is the facilitation term % SIGMA - the standard deviation for the Gaussian function % BETA - defines the factor of the facilitation % F1 - defines the factor for the negative gaussian (second) % F2 - defines the factor for the positive gaussian (first) % ORIENTATION - the orientation for this matrix (specified in radians) % POWER - defines the width of the kernel (the larger this number, the % smaller the kernel becomes) if (beta == 0) b = matrix; % no inhibition else w = facilitationkernel2D(sigma, f1, f2, orientation, power); % calculate the facilitationkernel t = convolution(facilterm, w); % calculate the facilitationterm b = matrix + beta*t; % apply the surround facilitation according to the facilitation factor BETA (+ instead of - (with inhibition)) end result = (b.*(b>0)); % set every negative value to 0 (H-function)