Coding of offer values in VS neurons.

<p><b>A.</b> Magnetic resonance image of monkey B. Recordings were made in the nucleus accumbens region of VS (highlighted in red; see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002173#pbio.1002173.s004" target="_blank">S4 Fig</a> for precise demarcation). <b>B.</b> Average responses of an example neuron (+/- 1 SEM in firing rate), separated by offer 1 reward size and probability. During epoch 1, this neuron showed higher firing rates for offers with larger reward sizes and probabilities. <b>C.</b> Scatter plot of each neuron’s coefficients for tuning for gamble probability (<i>x</i>-axis) and gamble reward size (<i>y</i>-axis). These coefficients were significantly correlated, consistent with a single value scale coding scheme. A least-squares regression line and confidence intervals are shown in red. Neurons are shown color-coded by regression coefficient <i>p</i>-value at α = 0.05. These data are available in Data S1 on figshare (<a href="http://figshare.com/articles/Data_for_Signatures_of_value_comparison_in_ventral_striatum_neurons_/1332487" target="_blank">http://figshare.com/articles/Data_for_Signatures_of_value_comparison_in_ventral_striatum_neurons_/1332487</a>).