Figure 11.

Blending of stimulus and error may also occur for a spatial stimulus. (A) The same stimulus image patterns that we used for a transition in time could also be used for a transition in space. To this end, a stimulus image was constructed by setting the checkerboard like pattern and the grating pattern side-by-side. (B) To study the response in space we used a computer model that explains the response of primary visual cortex to many different spatial stimuli (Spratling, 2010). We tested two different values of the epsilon parameter; generating a moderate (solid line) and strong (dashed line) spatial suppression. (C) The responses to image A were displayed separately for horizontally (green lines) and vertically preferring neurons (blue lines). At x ∼= 90 the horizontal response was larger than the vertical response, whereas when x increased the vertical was larger than the horizontal. This switch across space is similar to the switch we have shown across time in Figure 1F. (D) The results of this predictive coding model were also compared to the results of a pure feed forward model. A feed forward model was created by convolving the image with Gabor patches. (E–F) Same as in C–D but with a magnification around x = 90. Note that for the model of the primary visual cortex the horizontal unit is stronger activated than the vertical unit at x = 93 (arrow pointing upwards), whereas for a pure feed forward model the vertical unit is stronger activated than the horizontal unit at x = 93 (arrow pointing downwards).