Figure 5.

Neural network model. (A) Network architecture, with added non-verb competitor units in the posterior cortex and VLPFC layers to simulate prepotent competition, and added DLPFC layer that provides top-down support for relevant verb responses in the VLPFC to test this mechanism for prepotent selection. (B) Model simulates human RTs, showing effects of underdetermined and prepotent competition and their interaction. (C) Activation of the VLPFC units in each simulation condition. Both underdetermined and prepotent competition delay and reduce activation of winning verb responses (thin solid lines), due to competition from alternative responses (thick and dashed lines). Activation of non-verb competitors in the high prepotent competition conditions is reduced by top-down biasing from the DLPFC, which boosts activation of verb responses, helping them to out-compete non-verbs. LULP= low underdetermined competition/low prepotent competition, HULP= high underdetermined competition/low prepotent competition, LUHP= low underdetermined competition/high prepotent competition, HUHP= high underdetermined competition/high prepotent competition.