Supplementary Figure 7: Surrounds lack strong subthreshold spatial gradients but tend to have similar directional tuning to the principal whisker.
From: Spatiotemporal receptive fields of barrel cortex revealed by reverse correlation of synaptic input
a, For all neurons in either the adapted state (N = 71) or the unadapted state (N = 68), the dorso-ventral and caudal-rostral response gradients in the receptive fields were calculated as in previous studies (see Brumberg, Pinto & Simons 1996, Bruno & Simons 2002; i.e., (Responsedorsal – Responseventral) / (Responsedorsal + Responseventral) ) and a histogram of responses was plotted for the dorso-ventral bias (left) and caudal-rostral bias (right). b, Spatial gradients of latency of the surround response were similarly calculated. c, The relationship of the PW and SW tuning was calculated, for each neuron, as the mean correlation of the PW and each significantly responding surround whisker. A value of 1 would indicate that the directional tuning of all significant SWs were identical to the directional tuning of the PW; -1 that the directional tuning of all significant SWs were opposite to that of the PW. Note that, while SWs tend to be tuned like the PW, many cells are oppositely tuned or uncorrelated.
