FIG. 1.

Behavioral task and electrode locations: Animals had to press and hold a lever for a 1.0-s delay period and release the lever promptly (i.e., within 0.6 s) to receive a liquid reward. The end of the delay period was signified by a 72-dB 8-kHz tone; in some recording sessions, the tone was omitted on 50% of trials. If animals released the lever prior to the end of the 1.0-s delay or after the 0.6-s response window, then these trials were scored as errors (premature or late, respectively), and all behavioral devices (pump, lever and houselight) were extinguished for 4–8 s. B: electrode locations: Recording sites in dorsomedial prefrontal cortex (dmPFC) are shown from 8 animals that were implanted with microwire electrodes arrays in dmPFC (white dots) and from 7 animals that were implanted with microwire electrode arrays in motor cortex (black dots) and cannula in dmPFC (black crosses). Reconstructions are shown in frontal planes based on atlas sections (Paxinos and Watson 1982).