Neural correlates of directed forgetting in the avian prefrontal cortex

The authors trained 2 homing pigeons (Columba livia) on a directed forgetting task with 3 cues: a remember cue that was followed by a memory test and the opportunity to obtain a reward, a forget cue that was not followed by a memory test or a reward, and a free-reward cue that was not followed by a memory test but was followed by a free reward. The authors examined the activity of single neurons in the avian nidopallium caudolaterale, an area equivalent to the primate prefrontal cortex. Following the remember cue there was sustained neural activity during the delay period, whereas following the forget cue the neural activity in the delay period was significantly reduced. The activity following the free-reward cue mirrored that following the remember cue. The authors discuss the extent to which the findings are in line with the view that the sustained activity reflects memory for the sample stimulus or memory for reward.