Analysis of spiking synchrony in visual cortex reveals distinct types of top-down modulation signals for spatial and object-based attention
Fig 2
Two different types of G-cells (balls with “G”) are part of the model: spatial grouping cells (Gsp) and object-based grouping cells (Gobj). Whereas Gsp-cells implement spatial attention, i.e. attention to everything within a circumscribed spatially defined area, Gobj-cells impart grouping structure of objects in the scene and mediate object-based attention. The latter are similar to the grouping cells from refs [25, 26, 41]. Feedback signals from these G-cells modulate activity of BOS neurons (balls with “BOS”) by NMDA-type connections (gray downward pointing arrows). Black and gray ellipses represent the locations of RFs of BOS neurons which are driven by visual input through AMPA-type synapses (black upwards pointing arrows). Black and gray horizontal arrows from RFs point toward the preferred side of the corresponding BOS neuron. For description of subscripts and superscripts of BOS cells see text.