Figure 4: IB hypotheses and mechanism.

(a) Candidate mechanisms for IB. (b) Axes overlap of the direction, color, and target configuration axes for DLPFC and RNN data. The direction axis is more orthogonal to the color and target configuration axes. (c) Projections onto the potent space of the intra-areal dynamics for each area. We computed the potent projection of the direction axis, color axis, and a random vector with each area’s intra-areal dynamics matrix. We found intra-areal dynamics amplify color information in Area 1, and do not selectively attenuate color information in Areas 2 and 3. (d) Illustration depicting how the orientation of the axes affect information propagation. Information on the direction axis (orange) can be selectively propagated through inter-areal connections which information on the color axis (maroon) is not. (e) Inter-areal hypotheses. (f) Projections onto the potent space between areas for the color axis, direction axis, and random vector. Regardless of the dimension of the potent space, the direction axis is preferentially aligned with the potent space, indicating the information along this axis propagates, while the color axis is approximately randomly aligned. We emphasize the high alignment of the direction axis: the direction axis has a stronger alignment onto the first potent dimension of ${\mathbf{W}}_{21}$ than the remaining dimensions combined. Meanwhile, the color axis is aligned at nearly chance levels, and will therefore be propagated significantly less than the direction axis. Shading indicates s.e.m.