Figure 1. Experimental setup.

(A) The monkey controlled a computer cursor on a stereoscopic monitor viewed through a mirror, using neural signals. (B) Each recording session began with a brief calibration session to build the decoder. The decoder was used for a block of 3D trials (between 9 and 13 trials per target), followed by a block of 2D trials (between 15 and 27 trials per target). In some sessions, an additional block of 2D trials would proceed the blocks of 3D and 2D trials, or an additional block of 3D trails would follow the blocks of 3D and 2D trials. We focused our analyses on the first block of 3D trials and the block of 2D trials immediately following it (the gray boxes). In the supplementary materials, we demonstrate that our findings are invariant to the order of the blocks of trials. (C) Locations of the 26 targets in the 3D context. (D) Locations of the 16 targets in the 2D context. The eight targets that were common to the 2D and 3D contexts are shown in pink. The red, yellow, and light blue hoops represent the xy-plane, xz-plane, and yz-plane, respectively. Data of the target locations are available in Figure 1—source data 1.

DOI: http://dx.doi.org/10.7554/eLife.21409.003