Department of Psychology, University of Otago, Dunedin, New Zealand.
Eur J Neurosci. 2011 Feb;33(4):726-35. doi: 10.1111/j.1460-9568.2010.07540.x. Epub 2010 Dec 22.
In the current study, we examined whether delay activity in the avian equivalent of the prefrontal cortex (PFC) represents a neural correlate of a to-be-remembered sample stimulus or an upcoming reward. Birds were trained on a directed forgetting paradigm in which sample stimuli (red and white) were either followed by a cue to remember (high-frequency tone) or a cue to forget (low-frequency tone). The task also incorporated a differential outcomes procedure in which a correct response on the memory test following a red (remember) sample was rewarded with food, but correct responses on the memory test following the white (remember) sample were not. If delay activity represents a sample code, then it should be seen on both red-remember and white-remember trials. On the other hand, if delay activity represents a reward code, then delay activity should be seen only on red-remember trials, but not white-remember trials. Our findings suggest that activity in the avian PFC represents the outcome associated with each sample (reward or no reward) rather than memory for the sample itself.
在当前的研究中，我们考察了鸟类前额叶皮层（PFC）中的延迟活动是否代表了对要记住的样本刺激或即将到来的奖励的神经关联。鸟类接受了定向遗忘范式的训练，其中样本刺激（红色和白色）要么紧随提示要记住（高频音），要么紧随提示要忘记（低频音）。该任务还采用了差异结果程序，即在红色（记住）样本后的记忆测试中正确回答将获得食物奖励，但在白色（记住）样本后的记忆测试中正确回答则没有奖励。如果延迟活动代表样本代码，那么它应该在红色-记住和白色-记住试验中都能看到。另一方面，如果延迟活动代表奖励代码，那么延迟活动应该只在红色-记住试验中看到，而不是白色-记住试验中看到。我们的发现表明，鸟类 PFC 中的活动代表了与每个样本（奖励或无奖励）相关的结果，而不是对样本本身的记忆。
