Differential Effects of Early Hippocampal Pathology on Episodic and Semantic Memory

1. Differential Effects of Early Hippocampal Pathology on Episodic and Semantic Memory By: Vargha-Khadem, F., Gadian, D.G., Watkins, K.E., Connelly, A., & Van Paesschen, W. Presented by: Meinas Elmusharaf Safiah Mai Seung Ju Na Adam Ouellette Enakshi Singh

2. Meinas Methodology • Subject Recruitment • Sample size and representativeness • Control for between subject variance

3. Meinas • Contradiction relating to subjects’ overall quality of life and capabilities • Parents reported that everyday memory loss is: • Disabling • No child can be left alone • Cannot lead lives that are standard to their age, circumstances or aspirations The paper later goes on to report: “all three patients are not only competent in speech and language but have learned to read, write and spell at levels standard of their VIQs” “all three patients obtained scores ( on VIQS) within the normal range”

4. Meinas What if parents give bias rating that either exaggerate or underestimate their children’s memory impairment? Does the loss of episodic memory reduce the quality of life as the parents stated although an individual is still able to comprehend and express ideas through reading and writing?

5. Adam Validity & Reliability • Neuropsychological examinations • - Rey-Osterreith Complex Figure • Vargha-Khadem, F., Gadian, D.G., Watkins, K.E., Connelly, A., • & Van Paesschen, W. (1997) Differential Effects of Early • Hippocampal pathology on Episodic • and Semantic Memory. Science, 277, 376-379

6. Adam Validity & Reliability • Magnetic Resonance Techniques (1H MRS) • 2008-07-16 16:41 Dwayne Reed 256×256×8 (6156703 bytes) {{Information |Description=An animated gif of MRI images of a human head. For additional information contact me on my talk page. |Source=I created this image from an MRI performed on me last year at [[Stony Brook University Medical Center]]. |Date=July 16 • Vargha-Khadem, F., Gadian, D.G., Watkins, K.E., Connelly, A., & Van Paesschen, W. (1997) Differential Effects of Early Hippocampal pathology on Episodic and Semantic Memory. Science, 277, 376-379

7. Adam Validity & Reliability • Computerized Tests • Howard Echienbaum Is it necessary to have all these tests?

8. Seung Ju General Experimental Approach • Purpose is to assess the following views: • Both semantic and episodic memory is a unitary process that is dependent on the hippocampal system. • Temporal lobe amnesia results in a loss of episodic memory but preserves semantic memory • Single Dissociation: • Damage to hippocampus resulted in loss of episodic memory but semantic memory remained intact

9. Seung Ju Conclusiveness • Paper yields conclusive results based on: • Results from computerized tasks & neuropsychological tests • Evidence suggesting differential preservation of semantic memory • Findings in monkeys with hippocampal damage

10. Seung Ju • Conclusiveness Cont’d • Anatomical evidence • (1H MRS) • - ⓐ Control vs. ⓑ Beth • Conclusions made by Zola-Morgan and colleagues • Case of HM • Vargha-Khadem, F., Gadian, D.G., Watkins, K.E., Connelly, A., & Van Paesschen, W. (1997) Differential Effects of Early Hippocampal pathology on Episodic and Semantic Memory. Science, 277, 376-379

11. Enakshi Relevance • First to study cases of bilateral hippocampal damage that occurred at a very young age • Provided anatomical & behavioural evidence • Dissociation between episodic and semantic memory processing

12. Enakshi Relevance cont’d • Hippocampus  episodic memory • Parahippocampal cortices  semantic memory • Conflicting findings: • Some memory is spared because of lesion-induced plasticity • Squire & Reed: impaired semantic learning adult hippocampal damage • Brain reorganization after early MTL lesions?

13. Safiah Autism and the Medial Temporal Lobe Medial temporal lobe damage  Autism vs. Temporal-occipital cortex damage  Autism This paper demonstrated that those with damage to the medial temporal lobe had preserved cognitive and social development Autism and visual agnosia in a child with right occipital lobectomy. I Jambaqué, L Mottron, G Ponsot, and C Chiron (1998)J. Neurol. Neurosurg. Psychiatry 65, 555-560

14. Safiah Hypoxic-Ischaemic Injury and Medial Temporal Lobe Damage Hypoxic-ischaemic brain injury  medial temporal lobe damage causing amnesia Further studies also conducted by Vargha-Khadem include an additional two cases consistent with this finding Developmental amnesia associated with early hypoxic-ischaemic injury. D. G. Gadian, J. Aicardi, K. E. Watkins, D. A. Porter, M. Mishkin, and F. Vargha-Khadem (2000) Brain 123, 499-507

15. References • Vargha-Khadem, F., Gadian, D.G., Watkins, K.E., Connelly, A., & Van Paesschen, W. (1997) Differential Effects of Early Hippocampal pathology on Episodic and Semantic Memory. Science, 277, 376-379. • Gadian, D. G. , Aicardi, J., Watkins, K. E. , Porter, D. A., Mishkin, M. , & Vargha-Khadem, F. (2000). Developmental amnesia associated with early hypoxic-ischaemic injury. Brain 123, 499-507. • Jambaqué, I., Mottron, L., Ponsot, G., &Chiron, C. (1998). Autism and visual agnosia in a child with right occipital lobectomy. ). J. Neurol. Neurosurg.Psychiatry 65, 555-560. • Reed, J. & Squire, L. R. (1998). Retrograde Amnesia for Facts and Events: Findings from Four New Cases . J. of Neurosci 10, 3943-3954. • Braun, M, Carsten Finke1, Florian Ostendorf1, Thomas-Nicolas Lehmann2, Karl-Titus Hoffmann3 and Christoph J. Ploner