Figure 4. Orbitofrontal neurons accumulate responding during conditioning.

(A) Normalized responding to cue B and reward (ordered by their relative responding to cue B vs cue D) shows an increased fraction and diversity of responses over the course of the six conditioning days, while (B) normalized responding to cue D on each conditioning day shows more modest changes across conditioning. (C) These differences are evident in the fraction of neurons responding to each cue across the 6 days of conditioning. There were significantly more neurons responding to cue B in the final day of conditioning than the first (p>0.05, chi-squared test), with no significant change in the fraction responding to cue D.