The information that amnesic patients do not forget.

Abstract

The performance of three kinds of amnesic patients and control subjects was assessed using four methods for testing memory: free recall, recognition, cued recall, and word completion. Whereas amnesic patients were impaired on free recall, recognition, and cued recall, they were normal on word completion. Moreover, performance on the word-completion test declined at a normal rate reaching chance after about 120 min. The word-completion test resembled the cued-recall test in that the initial letters of previously presented words were given as cues. It differed from cued recall only in the instructions, which directed subjects away from the memory aspects of the test and asked them to complete each three-letter cue with the first word that came to mind. The present results offer an explanation of conflicting findings that have been obtained with amnesic patients on tests of the cued-recall type. The results are considered in terms of a process (activation or procedural learning), which is spared in amnesia and not dependent on the integrity of the damaged brain regions.

The Temporal Context Model in Spatial Navigation and Relational Learning: Toward a Common Explanation of Medial Temporal Lobe Function Across Domains.

“…Free recall is an episodic task in that performance requires that the subject recall the words presented in a particular episodic setting. Free recall is sufficiently sensitive to MTL damage that it can be used as a diagnostic tool for MTL damage in clinical settings (Graf, Squire, & Mandler, 1984). O'Keefe and Nadel (1978) proposed that the primary function of the hippocampus is to construct and read out "cognitive maps."…”

The Link Between Brain Learning, Attention, and Consciousness

“…To illustrate the implications of an ART i n terpretation of IThippocampal interactions, I will review how a lesion of the ART model's orienting subsystem creates a formal memory disorder with symptoms much like the medial temporal amnesia that is caused in animals and human patients after hippocampal system lesions (Carpenter and Grossberg, 1994;Grossberg and Merrill, 1996). In particular, such a lesion in vivo causes unlimited anterograde amnesia; limited retrograde amnesia; failure of consolidation; tendency to learn the rst event in a series; abnormal reactions to novelty, including perseverative reactions; normal priming; and normal information processing of familiar events (Cohen, 1984;Graf, Squire, and Mandler, 1984;Lynch, McGaugh, and Weinberger, 1984;Squire and Butters, 1984;Squire and Cohen, 1984;Warrington and Weiskrantz, 1974;ZolaMorgan and Squire, 1990). Unlimited anterograde amnesia occurs because the network cannot carry out the memory search to learn a new recognition code.…”

The consciousness continuum: from “qualia” to “free will”

“…(e.g., Warrington & Weiskrantz, 1971;Graf, Squire & Mandler, 1984). These patients are presumably accessing the material "unintentionally."…”