Figure 10.

Neuronal activity in orbitofrontal cortex after injections of isotonic MnCl₂. Single-unit activity was recorded while monkeys performed in the classical conditioning paradigm schematized in Figure 1. In this example from monkey T, a neuron within 1.4 mm of the injection site showed differential responses to both cues and outcomes in the CS+ (top) versus CS− (bottoms) trials. Rasters show firing rate (in hertz = spikes per second) as a function of time (in milliseconds). Dots represent individual spikes, and each row corresponds to a different trial. Spike density function curves (Gaussian kernel, SD of 25 ms) are superimposed on each raster. Data are aligned at the time of the cue appearance (0 ms; leftmost vertical line); the trial outcome occurred at 2500 ms (rightmost vertical line).