Figure 4. Simulations of the two proposed models of collective interaction and their predictions.

(A) The no exchange model was simulated by assuming that individuals cannot interpret the interaction forces and track the target as if they were alone under the influence of the mechanics of the elastic band. (B) This model predicted a larger inferior collective to be a greater hindrance to a superior individual of the collective, unlike the data where superior individuals maintained their performance. (C) In the neuromechanical goal sharing model, each individual built a representation of the partners’ average behavior to estimate the collective target. (D) The predictions from this model best explained the improvement of both inferior and superior individuals in the collective, and its modulation with the collective’s size.

Figure 4—figure supplement 1. Results of the control experiment from a different set of subjects who tracked a haptic target without visual feedback.

This experiment estimated how the interaction mechanics of coupling in dyads, triads and tetrads affected the quality of the estimated target from haptics. The compliance in the connection for dyads implies that dyads have more difficulty in estimating the collective target compared with triads and tetrads who felt a greater force. These values were used to adjust the neuromechanical goal sharing and the source separation limiting case.

Figure 4—figure supplement 2. The sum of the sum of squared error between the fits from the data and the simulation as a function of ${\displaystyle q}$ and ${\displaystyle {\mathit{\sigma }}_{\mathit{\mu }}^2}$.

The SSE is relatively insensitive to changes in the strength ${\displaystyle q}$. The model with the lowest SSE is the neuromechanical goal sharing model.