Fig. 4.

Neurons were selective for the identity of a sample immediately following its presentation but selective activity did not persist into subsequent task epochs. Population histograms of represent activity from the spatial task (A) and the color task (B) during trials in which the “best” sample, that most preferred by the neuron during the indicated trial epoch (solid curve), and the “worst” sample, that least preferred by the neuron during the indicated trial epoch (dashed curve), were presented at ordinal position 1 (left), ordinal position 2 (middle), or ordinal position 3 (right). “Best” and “worst” samples were identified independently for each ordinal position on the basis of trials not included in the histograms.