Fernández G, Heitkemper P, Grunwald T, Van Roost D, Urbach H, Pezer N, Lehnertz K, Elger C E
Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.
Hum Brain Mapp. 2001 Dec;14(4):251-60. doi: 10.1002/hbm.1057.
The participation of the inferior temporal cortex in visual word perception and recognition raises several questions: Is there a directed processing stream proceeding anteriorly by continuous cortical processing? How fast are words processed within such an inferior temporal stream? Does this stream support implicit or explicit memory? To answer these questions, we analyzed the spatio-temporal relationship of event-related potentials, recorded directly from the inferior temporal cortex in epilepsy patients performing a continuous visual word recognition paradigm. Event-related potentials elicited an inferior temporal positivity in a strip along the left collateral sulcus. This potential exhibited a linear (r = 0.74) peak latency progression from posterior to anterior inferior temporal regions (approximately 15 cm/sec), indicating a directed, intracortical processing stream. Peak amplitudes and latencies showed reliable old/new effects with smaller amplitudes and shorter latencies for old as opposed to new words. Although the amplitude-old/new-effect occurred for all repeated words (e.g., implicit memory), the latency-old/new-effect occurred for correctly recognized old words only (e.g., explicit recognition). These results seem to dissociate two distinct mnemonic processes. The graded decrease of mean ITP peak amplitudes and latencies, however, does not allow us to exclude a single trace model as assumed for explicit recognition memory based on familiarity (Mandler [1980]: Psychol Rev 87:252-271). Regardless whether there is a dissociation between implicit and explicit memory in inferior temporal cortex or not, our findings are in accordance with an integrated inferior temporal processing stream for words that performs continuously semantic and mnemonic operations supporting both implicit and explicit memory.
是否存在通过连续的皮质处理向前进行的定向处理流？在这样的颞下处理流中单词的处理速度有多快？这个流支持内隐记忆还是外显记忆？为了回答这些问题，我们分析了癫痫患者在执行连续视觉单词识别范式时直接从颞下回记录的事件相关电位的时空关系。事件相关电位在沿着左侧侧副沟的一条带中引发了颞下正电位。这个电位从颞下后部到前部区域呈现出线性（r = 0.74）的峰值潜伏期进展（约15厘米/秒），表明存在一个定向的皮质内处理流。峰值幅度和潜伏期显示出可靠的旧/新效应，旧单词的幅度较小且潜伏期较短，与新单词相反。尽管幅度上的旧/新效应在所有重复单词中都出现（例如内隐记忆），但潜伏期上的旧/新效应仅在正确识别的旧单词中出现（例 如外显识别）。这些结果似乎区分了两个不同的记忆过程。然而，平均颞下峰值幅度和潜伏期的逐渐减小并不能让我们排除基于熟悉度的外显识别记忆所假设的单一痕迹模型（曼德勒[1980]：《心理学评论》87：252 - 271）。无论颞下回中内隐记忆和外显记忆之间是否存在分离，我们的发现都与一个综合的颞下单词处理流一致，该流持续执行支持内隐记忆和外显记忆的语义和记忆操作。
