Evaluation of the MSM

Evaluation of the MSM

1. Clive Wearing

   • Who
     • Former musicologist and conductor
     • Contracted Herpes Simplex Encephalitas
       • Caused swelling in his brain which damaged his hippocampus
         • Unable to form new explicit memories (conscious recollection of experiences)
           • Anterograde amnesia
           • Demonstrated that hippocampus is essential in the creation of long-term memories
         • Lost some memories prior to disease
           • Retrograde amnesia
     • Implicit memories still intact
       • Able to do all motor tasks (e.g. play piano) he learned before disease
   • How it supports MSM
     • Could only hold info in STM for 20s
       • Memories were not transferred into LTM
         • Shows memories need to be rehearsed/pass through maintenance rehearsal loop multiple times before going to LTM

2. HM

   • Who
     • Henry Molaison
     • Suffered severe seiures
       • Had surgery which removed part of his hippocampus
     • Unable to form new LTM
   • How it supports MSM
     • Shows there are different parts of the brain for STM and LTM
       • LTM still intact
       • Differentiates STM from LTM

3. Neurological evidence and brain scans

   • What
     • MRI/fMRI
       • Uses strong magnetic field and radio waves to create image of brain
       • fMRI will show which parts of the brain are being stimulated by showing blood flow
     • Positron Emission Tomography (PET)
       • Radioactive tracer attaches to glucose in blood
       • Shows which areas of brain in use as activity areas will be utilizing glucose at higher rate
     • Neuroimaging
       • Non-invasive imaging techniques
         • Inc: MRI, MEG, EEG
     • Electroencephalogram (EEG)
       • Electrodes on scalp detect electrical impulses from neurones
   • Support/Contradict MSM
     • Support
       • Patients with damage to medial temporal lobe had impaired LTM but not STM
       • Patients with damage to perisylvian cortex showed difficulty in maintaining STM, but LTM unaffected
       • Distinguished between STM and LTM

4. Korsakoff Syndrome

   • Memory disorder caused by vitamin B1 deficiency
   • Supports MSM
     • Different STM and LTM
       • People with Korsakoff syndrome can recall last items in list (unimpaired recency effect), suggesting unaffected STM even though LTM was poor

5. Glanzer and Cunitz (1966)

   • Showed primacy and recency effect
     • When pp given a word list, they remembered first few words and last few words best
       • First words transferred to LTM as had time to rehearse
       • Last words stayed in STM
       • Middle words lost due to rehearsal of first words
       • Supports MSM as shows rehearsal needed to transfer to LTM
     • Supports existence of separate STM and LTM stores