Human amnesia and the medial temporal region: enduring memory impairment following a bilateral lesion limited to field CA1 of the hippocampus

  title={Human amnesia and the medial temporal region: enduring memory impairment following a bilateral lesion limited to field CA1 of the hippocampus},
  author={Stuart M. Zola-Morgan and Larry R. Squire and D. G. Amaral},
  booktitle={The Journal of neuroscience : the official journal of the Society for Neuroscience},
During the past 100 years clinical studies of amnesia have linked memory impairment to damage of the hippocampus. Yet the damage in these cases has not usually been confined to the hippocampus, and the status of memory functions has often been based on incomplete neuropsychological information. Thus, the human cases have until now left some uncertainty as to whether lesions limited to the hippocampus are sufficient to cause amnesia. Here we report a case of amnesia in a patient (R.B.) who… 
Three Cases of Enduring Memory Impairment after Bilateral Damage Limited to the Hippocampal Formation
The present results substantiate the idea that severity of memory impairment is dependent on locus and extent of damage within the hippocampal formation and that damage to the hippocampusal formation can cause temporally graded retrograde amnesia.
Organic Amnesia
A now-famous patient with organic amnesia, case H. M. M., who in 1953 underwent surgery for relief of severe epileptic seizures, exhibited a profound anterograde amnesia following surgery, but there was no detectable impairment in intellectual or language abilities.
Permanent global amnesia: case report.
This case, the first with a detailed cognitive examination, is evidence of a relatively pure hippocampal pattern for memory loss in permanent global amnesia, related to hippocampal damage.
The medial temporal-lobe amnesic syndrome.
  • B. Milner
  • Psychology, Biology
    The Psychiatric clinics of North America
  • 2005
Hippocampal abnormalities in amnesic patients revealed by high-resolution magnetic resonance imaging
A high-resolution protocol for imaging the human hippocampus with magnetic resonance is developed that permits visualization of the hippocampal formation in substantial cytoarchitectonic detail, revealing abnormalities in patients with severe and selective memory impairment.
Temporally‐specific retrograde amnesia in two cases of discrete bilateral hippocampal pathology
The absence of extensive retrograde amnesia in these two cases points to a time‐limited role for the hippocampus in the retrieval of retrograde memories, and suggests that entorhinal, perirHinal, parahippocampal, or neocortical areas of the temporal lobe may be more critical than the hippocampus proper for long‐term retrograde memory functioning.
Human amnesia and the medial temporal lobe illuminated by neuropsychological and neurohistological findings for patient E.P.
Detailed neurohistological findings for this case of bilateral, symmetrical damage to the medial temporal lobe and well-documented memory impairment indicate that E.P.’s severe memory impairment was caused by his medial temporal lesions, whereas his impaired semantic knowledge was cause by lateral temporal damage.
Lesions of the hippocampal formation but not lesions of the fornix or the mammillary nuclei produce long-lasting memory impairment in monkeys
A group of tasks sensitive to human amnesia were used to characterize the severity and duration of memory impairment in monkeys following bilateral damage to the hippocampal formation, fornix, or
Enduring memory impairment in monkeys after ischemic damage to the hippocampus
Results provide additional evidence that the hippocampus is a focal site of pathological change in cerebral ischemia, and that damage limited to the hippocampal formation is sufficient to impair memory.


Multimodal amnesic syndrome following bilateral temporal and basal forebrain damage.
Because several anatomic and behavioral characteristics of this case are different from those of previously reported cases of amnesia, they may provide new insight into the neuroanatomic substrate of human memory.
It is concluded that the anterior hippocampus and hippocampal gyrus, either separately or together, are critically concerned in the retention of current experience.
Memory in monkeys severely impaired by combined but not by separate removal of amygdala and hippocampus
A discrepancy between the clinical and animal literature could indicate a true evolutionary shift in the functions of the hippocampus, or, at the other extreme, it could simply reflect the use of incommensurate measures across species.
Are hippocampal lesions sufficient to cause lasting amnesia?
The findings support the view that the hippocampus is itself a critical structure in the medial temporal diencephalic memory circuit and if bilateral lesions are necessary for the production of permanent amnesia.
Dorsal thalamic lesion in a noted case of human memory dysfunction
CT scans have localized a lesion in the left dorsal thalamus of this patient in a position corresponding to the dorsomedial nucleus, which may be critical in the neuropathology of diencephalic amnesia and, in humans, may be required for normal functions.
Retrograde amnesia and remote memory impairment
Comparative aspects of studies of amnesia.
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  • Psychology, Biology
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences
  • 1982
The evidence from man suggests that in the amnesic syndrome the integrity is preserved of those forms of long-term memory that do not depend on the operation of a 'mediational' memory system.
Memory impairment in monkeys following lesions limited to the hippocampus.
The level of impairment does not appear to be due to any of the following factors: time of testing after surgery, prior postoperative testing, surgical techniques, species differences, or behavioral training methods, but preoperative training experience does appear to reduce the severity of the impairment.
Persistent anterograde amnesia after stab wound of the basal brain
Preserved learning in monkeys with medial temporal lesions: sparing of motor and cognitive skills
  • S. Zola-Morgan, L. Squire
  • Psychology, Biology
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1984
Monkeys with H-A lesions are normal at skill learning like human amnesic patients with similar lesions, and this conclusion depends in part on the argument developed here that pattern discrimination learning, as accomplished by monkeys, has a large skill-like component.