Fig. 2: Progress-to-goal is a key feature of task-tuned neurons in the medial frontal cortex.

a, 3D rendering of probe channel positions, with the inset showing mFC regions (Using HERBs⁵⁷). Contacts were mostly in prelimbic cortex (PrL) but also in anterior cingulate cortex (ACC), infralimbic cortex (IrL) and secondary motor cortex (M2). Mouse IDs: 0, me08; 1, ah03; 2, me10; 3, me11; 4, ah04; 5, ab03; 6, ah07. b, Schematics of polar plots used to project neuronal activity onto the circular task structure. The radial and angular axes represent firing rate and task position, respectively. Dashed lines along the cardinal directions represent reward (goal) times in each state. c, Neurons are tuned to the relative progress to goal of the mouse (goal-progress tuned). Top, a raster plot of firing activity in one state (C: orange segment of polar plot below) of a cell that consistently fires shortly before a goal is reached. Bottom, polar plots of task activity for five separate neurons, with maximum firing rates (Hz) on the top right of each polar plot. d, Bottom, some goal-progress-tuned cells are additionally modulated by state in a given task (goal-progress + state-tuned). Top, polar plots and spatial maps for a spatially tuned and state-tuned neuron (left) and a non-spatially tuned and state-tuned neuron (right) across two distinct task configurations. e, Two example goal-directed paths and overlaid spiking of three mFC neurons tuned to early, intermediate and late goal progress, regardless of the spatial trajectory of the mouse. f, Goal-progress tuning is consistent across tasks that differ in reward locations. Left, the average firing rate vector of all neurons relative to an individual goal (averaged across all states) arranged by peak goal-progress bin in task X. This alignment is largely maintained in tasks Y and Z as well as a later session of the first task (X′). Right, histogram showing the mean goal-progress vector correlation across tasks for each neuron. One-sample, two-sided t-test against 0: n = 2,461 neurons; t-statistic = 104.3; P = 0.0, d.f. = 2,460. g, Pie chart showing the proportion of all neurons that are goal-progress tuned: 74%; two proportions test: n = 1,252 neurons, z = 35.5, P = 0.0. h, Plot of the mean task manifold derived from UMAP embedding. The same manifold is shown twice to emphasize goal-progress tuning (left) and state tuning (right). The task manifold is composed of goal-progress subloops. i, Distances along the three-dimensional manifold across different states and opposite goal-progress bin, across different states but for the same goal-progress bin or across different states and same goal-progress bin for a shuffled control. n = 20 double days; two-sided t-tests with Bonferroni correction: across-goal progress versus within-goal progress: t-statistic = 6.09, P = 2.25 × 10⁻⁵, d.f. = 19; across-goal progress versus permuted control: t-statistic = 26.0, P = 7.85 × 10⁻¹⁶, d.f. = 19; within-goal progress versus permuted control: t-statistic = 8.63, P = 1.60 × 10⁻⁷, d.f. = 19. Data are mean ± s.e.m. a.u., arbitrary units.