Larry Squire

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..We also indicate ways in which the functions of the medial temporal lobe structures are different, and suggest that these structures work together in a cooperative and complementary way...

..This article traces the development of these ideas and provides a current perspective on how these brain systems operate to support behavior...

..The findings suggest that the capacity for imagining the future, like the capacity for remembering the remote past, is independent of the hippocampus...

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..The available evidence tells a coherent story and leads to some straightforward conclusions about the neuroscience of remote memory...

..This work provides a straightforward and illuminating perspective on the question and confirms the view that first emerged from less direct evidence...

..The findings show that auditory recognition, like recognition memory in other sensory modalities, is dependent on the medial temporal lobe...

..It is therefore encouraging that many opportunities exist for moving beyond purely descriptive studies to studies that involve treatments or manipulations directed toward yielding information about mechanisms...

..Work with H.M. established fundamental principles about how memory functions are organized in the brain...

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..To assess whether single-time-point and longitudinal volumetric magnetic resonance (MR) imaging measures provide predictive prognostic information in patients with amnestic mild cognitive impairment (MCI)...

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..Possible reasons for these findings are discussed in the context of the specific performance requirements of the water maze task...

..Together, the findings suggest that medial temporal lobe structures broadly support recognition memory function and that item memory and source memory similarly depend on these structures...

..These results indicate that impaired performance in the water maze after hippocampal damage reflects more than a loss of spatial information...

..What determines whether remote spatial memory is preserved or impaired following disruption of hippocampal function appears to be the type of task used to assess spatial memory, not the method used to disrupt the hippocampus...

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..quot; These findings indicate that perirhinal cortex is not needed for visual perception across a wide range of visual perceptual tasks...

..The findings emphasize the difference in the extent of retrograde amnesia associated with hippocampal lesions and large MTL lesions...

..The results show the importance of the hippocampus and related structures for nonspatial memory and also demonstrate the temporary role of these structures in long-term memory...

..We suggest that E.P.'s learning depended on a process akin to perceptual learning and occurred directly within neocortex...

..M. and W.H.), who also had reductions in hippocampal size of about 40%, we suggest that a volume reduction in this range likely indicates a nearly complete loss of hippocampal neurons...

..The results show that the hippocampal region supports semantic memory as well as episodic memory and that its role in the acquisition and storage of semantic knowledge is time limited...

..We suggest that an alternative method can be used to effectively investigate recollection and familiarity in the MTL, one that is valid whether recollection is a categorical or a continuous process...

..These findings suggest that the functional organization of the medial temporal lobe is probably best understood in terms unrelated to the distinction between recollection and familiarity...

..The presentation of patients with functional amnesia is as variable as humankind's concept of what memory is and how it works...

..Yonelinas et al. (2002) also analyzed remember/know judgments and ROC data in an effort to show that recollection is selectively impaired in patients, but these analyses also raise problems...

..Attention is given to two prominent behavioral paradigms (delayed nonmatching to sample and tests of spontaneous novelty preference)...

..Alternatively, it is possible that in these tasks hippocampal lesions might produce an impairment in performance that prevents the expression of an otherwise intact spatial memory...

..Hippocampal lesions produced moderate and reliable memory impairment. The results suggest that the hippocampus is important for object recognition memory...

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..This pattern of performance suggests that the hippocampus supports both recollection and familiarity...

..These findings suggest that activity in the medial temporal lobe is predictive of subsequent memory strength, whereas activity in prefrontal cortex is predictive of subsequent recollection...

..Similar results were obtained in the parahippocampal gyrus. Unlike in the medial temporal lobe, activation in prefrontal cortex increased differentially in association with source recollection...

..Accordingly, activity in the medial temporal lobe can be modulated by the old/new status of stimuli and does not always track the behavioral response...

..The acquired knowledge was rigidly organized, and performance collapsed when the task format was altered...

..These findings show that the hippocampus is important for both spatial memory and recognition memory. However, spatial memory performance requires more hippocampal tissue than does recognition memory...

..These results suggest that the component processes that determine the shape of the ROC are operative in the absence of the hippocampus, and they argue against the idea that the hippocampus selectively supports the recollection process...

..Accordingly, the results raise the possibility that the acquisition of conscious (declarative) knowledge about the world cannot be supported by structures outside the MTL, even with extended exposure. Published 2004 Wiley-Liss, Inc...

..A number of other considerations suggest that the neocortex ultimately supports the capacity for recollecting remote autobiographical memory...

..Considered together with related studies of humans and nonhuman primates, the findings suggest that different species will approach the same task in different ways...

..The findings show that experience-dependent eye movements in response to altered scenes reflect conscious, declarative memory, and they support the link between aware memory, declarative memory, and hippocampus-dependent memory...

..These findings illuminate several issues regarding the relation between diencephalic and medial temporal lobe amnesia, the status of recognition memory in amnesia, and the neuroanatomy of memory...

..Olfactory recognition memory, similar to recognition memory in other sensory modalities, depends on the integrity of the hippocampal region...

..The results support the idea that medial temporal lobe structures play a time-limited role in semantic memory...

..The patients were impaired on all three tasks. We consider possible explanations for the difference between the findings for humans and rats, including the fact that olfactory function is particularly well-developed in rodents...

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..These neurons appear to represent memorized stimulus associations that are stable across variations in behavioral performance. In addition, many neurons (74%) were modulated by the spatial arrangement of the stimuli in the display...

..The findings indicate that awareness is critical for robust performance on tests of transitive inference and support the view that awareness of what is learned is a fundamental characteristic of declarative memory...

..We conclude that damage to the hippocampus does not selectively impair viewpoint-independent spatial memory. Rather, hippocampal damage impairs memory as the memory load increases...

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..Furthermore, the results support the principle that the ability to acquire new memories is a distinct cerebral function, dissociable from other perceptual and cognitive functions...

..Considering that H.M.'s lesion, both medially and laterally, is less extensive than the lesions in these other patients, it appears unlikely that his shortcomings in language production are related to his temporal lobe lesion...

..This finding suggests that both structures cooperate during learning to determine the memory strength of what is being learned...

..When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration...

..These findings support the conclusion that working memory (active maintenance) is intact after medial temporal lobe damage...

..In view of the fact that there are only 14 possible annual calendars, we suggest that both savants worked by memorizing these 14 possible calendar arrangements...

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..Awareness of stimulus contingencies is not required for differential delay eyeblink conditioning when simple conditioned stimuli are used...

..We discuss our findings in the light of the work by Kroll et al. (1996) and other recent neuropsychological, electrophysiological, and neuroimaging studies of hippocampal function and single-item and associative memory...

..Thus, the associative condition was not disproportionally difficult for the amnesic patients. These results are consistent with the idea that the hippocampus is similarly involved in single-item and associative memory...

..Impaired remote autobiographical memory, which has sometimes been reported with this and other tests, is likely caused by significant damage outside the medial temporal lobe...

..A second key component of our program is our new work with rats, which is conceptually closely related to our work with humans. ..

..A final objective is to determine in animal studies the relationship between current parameters of electroconvulsive shock (ECS) and amnesia...

..A second key component of the work is the close conceptual relationship between the rodent program and the work with humans. ..