Purchase this article with an account.
Chun-I Yeh, Dajun Xing, RobertM Shapley; How receptive field properties of V1 neurons change with different stimulus ensembles. Journal of Vision 2011;11(11):1170. doi: 10.1167/11.11.1170.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Many V1 simple cells show a strong contextual effect – their receptive fields vary when measured with different stimulus ensembles. By using Hartley subspace (HS, Ringach et al., 1997) and sparse noise (SN, Jones and Palmer, 1987) stimuli to map monkey V1 receptive fields, we showed that the contextual effect was bigger for output layer-2/3 than for input layer-4c neurons (Yeh et al., 2009). In comparison to HS maps, SN maps of layer-2/3 neurons have shorter aspect ratios, smaller numbers of subfields, and show greater black-dominance (stronger OFF-subregions, Yeh et al., 2009). It remains unclear what stimulus parameters are critical for the observed changes in receptive field properties. Here we introduced a third stimulus ensemble – a binary checkerboard white noise (WN, m-sequence, Reid et al., 1997) to map the receptive field. WN and HS are dense stimuli that activate simultaneously a larger population of neurons than SN. Unlike HS stimuli, neighboring pixels of WN and SN stimuli are uncorrelated. Receptive fields measured with the three different stimuli were fitted with a two-dimensional Gabor function. For layer-2/3 simple cells (f1/f0 > 1), we found: 1) the aspect ratio of HS maps (3.22 + 1.43, mean + s.d.) was significantly larger than that of WN (1.83 + 0.61) and SN maps (1.48 + 0.24); 2) the number of subregions was largest for HS (3.10 + 1.36), followed by WN (1.80 + 0.39), and smallest for SN maps (1.33 + 0.24); 3) black-dominance, as measured by the spatial phase angle of the best-fitting Gabor function (0°: white dominated, 90°: white/black balanced, 180°: black dominated), was more evident for SN (155° + 29.8°) than for HS (116° + 54.1°) and WN (133° + 38.8°). These results suggest that measurement of more elongated subfields, and more subregions, may be attributed mostly to spatial correlations of the HS stimuli, but the strong black dominance in layer-2/3 cells can be attributed to the spatial sparseness of the SN stimuli.
This PDF is available to Subscribers Only