Top, the D 2 value of neuronal activity (the degree to which specific features explained neuronal response, n = 272 units) during word planning (green) and production (orange) sorted across all population neurons. Middle, relationship between explanatory power ( D 2 ) of neuronal activity ( n = 272 units) for phonemes (Spearman’s ρ = 0.69), syllables (Spearman’s ρ = 0.40) and morphemes (Spearman’s ρ = 0.08) during planning and production ( P = 1.3 x 10 -39 , P = 6.6 x 10 -12 , P = 0.18, respectively, two-sided test of Spearman rank-order correlation). Bottom, the D 2 metric for each cell during production per feature ( n = 272 units).
