Charles David P, Gaffan David, Buckley Mark J
Department of Experimental Psychology, Oxford University, Oxford OX1 3UD, United Kingdom.
J Neurosci. 2004 Feb 25;24(8):2037-44. doi: 10.1523/JNEUROSCI.3796-03.2004.
Over four experiments based on the delayed matching-to-sample task, fornix-transected and normal control monkeys were presented with a sequence of five sample stimuli and then received intermixed within-session recency (WSR) and between-session recency (BSR) tests in experiment 1, only BSR tests in experiment 2, only absolute novelty (AN) tests in experiment 3, or only WSR tests in experiment 4. In WSR tests, monkeys chose which of two samples had occurred more recently in the immediately preceding sequence. In BSR and AN tests, monkeys were required to choose one sample from the immediately preceding sequence in preference to a foil unseen in the present session (BSR) or an AN foil that had never been presented before. When tests of WSR and BSR were intermixed (experiment 1), fornix monkeys performed below the level of the control monkeys in both types of test, although this difference was not statistically significant. In experiment 2, fornix monkeys were significantly impaired on tests of BSR alone, in which memory for a stimulus presented in an immediately preceding sequence could compete with memory for a foil presented in an earlier training session. In tests of AN (experiment 3), fornix monkeys performed at the same level as control animals in distinguishing a previously experienced stimulus from a previously unseen foil. In experiment 4, fornix transection significantly impaired tests of WSR alone. Taken together, these results suggest that one specialized role of the fornix is to process temporal information.
在基于延迟匹配样本任务的四项实验中，对穹窿横断的猴子和正常对照猴子呈现一系列五个样本刺激，然后在实验1中接受会话内近因效应（WSR）和会话间近因效应（BSR）的混合测试，在实验2中仅接受BSR测试，在实验3中仅接受绝对新颖性（AN）测试，或在实验4中仅接受WSR测试。在WSR测试中，猴子要选择在紧接的前一个序列中出现时间更近的两个样本中的哪一个。在BSR和AN测试中，要求猴子从紧接的前一个序列中选择一个样本，而不是选择在当前会话中未见过的陪衬刺激（BSR）或从未呈现过的AN陪衬刺激。当WSR和BSR测试混合进行时（实验1），穹窿横断的猴子在这两种测试中的表现均低于对照猴子，尽管这种差异没有统计学意义。在实验2中，穹窿横断的猴子仅在BSR测试中显著受损，在该测试中，对紧接的前一个序列中呈现的刺激的记忆可能会与对早期训练会话中呈现的陪衬刺激的记忆相互竞争。在AN测试（实验3）中，穹窿横断的猴子在区分先前经历过的刺激和先前未见过的陪衬刺激方面与对照动物表现相当。在实验4中，穹窿横断显著损害了仅WSR测试的表现。综合来看，这些结果表明穹窿的一个特殊作用是处理时间信息。
