Semantic knowledge in patient H.M. and other patients with bilateral medial and lateral temporal lobe lesions

  title={Semantic knowledge in patient H.M. and other patients with bilateral medial and lateral temporal lobe lesions},
  author={Heike Schmolck and Elizabeth A. Kensinger and Suzanne Corkin and Larry R. Squire},
We investigated the effects of damage to the medial temporal lobe (MTL) and anterolateral temporal cortex on semantic knowledge. We studied eight male controls, two patients with lesions limited to the hippocampal formation, three postencephalitic patients with extensive MTL lesions and variable damage to the lateral temporal cortex, and patient H.M. (whose lesion is limited mostly to the MTL, but who also has minimal damage to the anterolateral cortex). On 13 tests of semantic memory, patients… 
The anatomy of semantic knowledge: medial vs. lateral temporal lobe.
  • D. Levy, P. Bayley, L. Squire
  • Psychology, Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2004
It is concluded that medial temporal lobe damage impairs the formation of declarative memory, and that semantic knowledge is impaired to the extent that damage extends laterally in the temporal lobe.
Differences in visual naming performance between patients with temporal lobe epilepsy associated with temporopolar lesions versus hippocampal sclerosis.
Evidence is provided that temporal pole damage produces or contributes to naming impairment in TLE, while also suggesting that the hippocampus is not critical for naming, which highlights the importance of error-type analysis when evaluating visual naming in Tle.
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.
The Fate of Old Memories after Medial Temporal Lobe Damage
The findings emphasize the difference in the extent of retrograde amnesia associated with hippocampal lesions and large MTL lesions.
Anomia in patients with left inferior temporal lobe lesions
Background: Damage to left inferior temporal cortex has been associated with naming deficits resulting either from impaired access to phonological word forms (pure anomia) or from degraded semantic
Failure to acquire new semantic knowledge in patients with large medial temporal lobe lesions
The results demonstrate that the capacity for new semantic learning can be absent, or nearly absent, when there is virtually complete damage to the MTL bilaterally, and raise the possibility that the acquisition of conscious (declarative) knowledge about the world cannot be supported by structures outside the M TL, even with extended exposure.
Stimulus familiarity modulates functional connectivity of the perirhinal cortex and anterior hippocampus during visual discrimination of faces and objects
It is suggested that in order to benefit from stimulus familiarity, it is necessary to engage not only the perirhinal cortex and hippocampus, but also a network of regions known to represent semantic information.
Lexical retrieval and semantic knowledge in patients with left inferior temporal lobe lesions
Whether anomia following unilateral left inferior temporal lobe damage reflected a loss of semantic knowledge or a post‐semantic deficit in lexical retrieval and to identify the neuroanatomical correlates of the naming impairment are determined.
The Role of the Left Temporal Lobe in Naming and Semantic Knowledge
Background: Anomia is often demonstrated by individuals who sustain damage to the left inferior temporal lobe. The nature of the anomia in individuals with damage to anterior regions of the left
Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy
A review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the amygdala.


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.
H. M.’s Medial Temporal Lobe Lesion: Findings from Magnetic Resonance Imaging
The view that lesions of the hippocampal formation and adjacent cortical structures can produce global and enduring amnesia and can exacerbate amnesia beyond that seen after more selective hippocampal lesions is reinforced.
Bilateral medial temporal lobe damage does not affect lexical or grammatical processing: Evidence from amnesic patient H.M.
It is concluded that medial temporal lobe structures are not critical for retention and use of already acquired lexical information or for grammatical processing, but they are required for acquisition ofLexical information, as evidenced in previous studies revealing H.M.'s profound impairment at learning new words.
Memory, Language, and Neuroanatomy: A Reply
The interpretation is that the hippocampal formation is not essential for understanding ambiguity and that memory impairment can occur in isolation from an impairment in understanding ambiguity.
Retrograde Amnesia for Facts and Events: Findings from Four New Cases
Tests of anterograde and retrograde memory function suggest that whether retrograde amnesia is temporally limited or very extensive depends on whether the damage is restricted to the hippocampal formation or also involves additional temporal cortex.
Detection and explanation of sentence ambiguity are unaffected by hippocampal lesions but are impaired by larger temporal lobe lesions
The ability to comprehend ambiguity is independent of the hippocampal formation and three patients with larger temporal lobe lesions, which extended beyond the medial temporal lobe, were impaired to about the same degree as the noted amnesic patient H.M.
Intact Perceptual Priming in a Patient with Damage to the Anterior Inferior Temporal Lobes
The results suggest that the anterior IT is not involved in the storage of pre-existing structural descriptions of known objects, the ability to create new structural descriptions for novel objects, and the able to compute descriptions that are invariant with respect to changes in size and reflection.
The results of these studies point to the importance of the hippocampal complex for normal memory function in patients who had undergone similar, but less radical, bilateral medial temporallobe resections, and as a warning to others of the risk to memory involved in bilateral surgical lesions of the hippocampusal region.
A neural basis for the retrieval of conceptual knowledge
Differing patterns of temporal atrophy in Alzheimer’s disease and semantic dementia
Hippocampal atrophy is not specific for AD but is also seen in semantic dementia, and these findings have implications for diagnosis and understanding of the cognitive deficits in AD and semantic dementia.