Enhanced sensitivity for peripherally-presented collinearly-aligned stimulus elements: contour detection or spatial summation?
Chris Tailby, Olga Cubells, Andrew Metha
Clinical and Experimental Optometry | Published : 2001
BACKGROUND: It has been shown that the detection threshold for a foveally presented Gabor stimulus (Gaussian-windowed sinusoidal grating) is reduced in the presence of two suprathreshold flanking Gabors and that such facilitation is orientation and configuration dependent, with maximal threshold reductions occurring with collinear flanking elements. METHODS: We assessed the effect of varying relative orientation on detection thresholds for chains of three Gabors, with 0.96(o) centre-to-centre spacing, presented at 4.8(o) in the periphery. The central Gabor element in each chain was either collinear with its flanking elements or oriented orthogonally to them. RESULTS: Thresholds for the confi..View full abstract