Abnormal categorization and perceptual learning in patients with hippocampal damage
Abnormal categorization and perceptual learning in patients with hippocampal damage
复制标题
DOI：
10.1523/jneurosci.1535-06.2006
复制
发表时间：
2006-07-19
影响因子：
5.3
通讯作者：
Saksida, Lisa M.
中科院分区：
文献类型：
--
作者：
Graham, Kim S.;Scahill, Victoria L.;Saksida, Lisa M.
流行的理论认为，内侧颞叶（MTL）专门帮助陈述性记忆，而非陈述性记忆是独立的大脑区域。然而，最近对健忘症患者的研究表明，陈述性记忆任务的表现可能并不总是依赖于单个MTL记忆系统，而是突出了解剖学上不同的结构在处理不同刺激类型中的关键作用。特别是，海马体与空间记忆有关，而嗅周皮层似乎对物体记忆至关重要。为了评估刺激类型是否也是非陈述性记忆的一个关键维度，对选择性海马损伤的患者进行了简单分类和面部和虚拟现实场景的感知学习测试。患者表现出保留的分类和知觉学习的面孔，但异常的表现时，要区分的刺激是虚拟现实场景。这些发现意味着，刺激类型可能是一个更重要的预测性能的记忆任务（陈述性和非陈述性）比以前认为。他们还认为，在某些情况下，MTL损伤后良好的非陈述性记忆的报告可能只是反映了使用的刺激未能利用依赖于该区域结构的过程，例如海马体的空间处理。
Prevailing theory holds that the medial temporal lobe (MTL) subserves declarative memory exclusively, whereas nondeclarative memory is independent of this brain region. Recent studies in patients with amnesia, however, have shown that performance on declarative memory tasks may not always be dependent on a single MTL memory system, instead highlighting the critical role of anatomically distinct structures in processing different stimulus types. In particular, the hippocampus has been implicated in spatial memory, whereas perirhinal cortex seems critical for object memory. To assess whether stimulus type would also be a key dimension in nondeclarative memory, patients with selective hippocampal lesions were tested on simple categorization and perceptual learning of faces and virtual reality scenes. The patients demonstrated preserved categorization and perceptual learning of faces but abnormal performance when the stimuli to be discriminated were virtual reality scenes. These findings imply that stimulus type may be a more critical predictor of performance on memory tasks (declarative and nondeclarative) than previously thought. They also suggest that reports of good nondeclarative memory after MTL damage may, in some cases, simply reflect the use of stimuli that fail to tap the processes dependent on structures in this region, such as spatial processing in the case of the hippocampus.