Collinear Suppression in Texture Segmentation for Temporally Modulated Stimuli
Collinear stimuli facilitate the neural signal in the case of Gabor's stimuli when a low-contrast stimulus inside the receptive field is flanked by higher contrast collinear elements located in surrounding regions of the visual space. Our previous studies pointed to the contextual modulation in the case of the textured stimuli. Collinear suppression was observed in 63% of the responses. In the current research we used Gabor's primitives for building the circular texture objects of vertical and diagonal orientation to be recognized on the horizontally-oriented background in the presence of collinear and orthogonal peripheral stimuli. The two-alternative forced choice (2AFC) psychophysical method with constant stimuli was used to gather the responses of the subjects which choose between left or right position of diagonally-oriented stimuli. The experimental stimuli consisted of two circularly shaped objects presented in visual angle of 2.76 degrees. The expositions of the stimuli varied from 13.3 to 93.3 ms arbitrarily. Visual stimuli were presented with a CRS Visage stimulus generator and shown on a CRT monitor of 75 Hz refresh rate. Our new findings support the concept of suppressing the target stimuli of the same orientation in the presence of a peripheral collinear stimulation.
If the inline PDF is not rendering correctly, you can download the PDF file here.
Scialfa C. T. & Hamaluk E. (2001). Aging Texture Segmentation and Exposure Duration: Evidence for a Deficit is Preattentive Processing. Experimental Aging Research 27 123-135.
Chalupa L. M. & Werner J. S. (2004). The Visual Neurosciences. Vol. 1. Cambridge (MA) London England: A Bradford Book (the MIT Press).
Petrov Y. Carandini M. & McKee S. (2005). Two Distinct Mechanisms of Suppression in Human Vision. J. Neurosci. 25(38) 8704-8707.
Carandini M. (2004). Receptive fields and suppressive fields in the early visual system. The cognitive neurosciences Ed.3 313-326. Cambridge MA: MIT Press.
Norton T. T. Corliss D. A. & Bailey J. E. (2002). The Psychophysical Measurement of Visual Function. USA: Butterworth Heinemann
Fomins S. & Zarina L. (2009). Segmentation of instant isoluminant chromatic textures. Perception 38. ECVP Supplement p.54
Polat U. Mizobe K. Pettet M. W. Kasamatsu T. & Norcia A. M. (1998). Collinear stimuli regulate visual responses depending on cell's contrast threshold. Nature 391 580-584
Chalupa L. M. & Werner J. S. (2004). The Visual Neurosciences. Vol. 2. Cambridge Massachusetts London England: A Bradford Book (the MIT Press).
Li Z. (1999). Contextual influences in V1 as a basis for pop out and asymmetry in visual search. Proc. Natl. Acad. Sci. USA Vol. 96 10530-10535.
Li Z. (1999). Primary visual cortex as a saliency network for pre-attentive segmentation. In: 3rd Annual Vision Research Conference Pre-attentive and Attentive Mechanisms in Vision Florida USA May 7-8.