Figure 3.

Reference frame classification. For each neuron, the abscissa shows the DI value for the Head-vs-Body condition and the ordinate shows the DI value for the Eye-vs-Head condition. Eye-centered (blue cross), head-centered (green cross), and body-centered (red cross) reference frames are indicated by the coordinates (1, 1), (1, 0), and (0, 0), respectively. Open circles and triangles denote visual heading tuning data (monkey E, n = 42; monkey Q, n = 7). Small filled gray symbols denote vestibular heading tuning data from the study of Chen et al. (2013b) (n = 76). Blue open symbols represent neurons that were significantly classified as eye centered, whereas gray open symbols represent neurons that were unclassified (for details, see Materials and Methods). Black open symbols denote neurons with intermediate reference frames on both axes. Note that no neurons with head-centered (green) or body-centered (red) visual heading tuning were found in VIP. The star represents the example neuron shown in Figure 1.