PSY493H1 Lecture Notes - Lecture 5: Afterimage, Brenda Milner, William Beecher Scoville
Document Summary
Stages of learning and memory: encoding = study phase, storage and consolidation = retention interval, retrieval = test phase. Neurosurgeon, william scoville, performed a bilateral medial temporal lobe resection to treat molaison"s epilepsy that was irresponsive to anticonvulsant medications. Parahippocampal gyrus on each side though with some of the posterior aspects being spared. Although the surgery was successful in its intended purpose, the partial lobectomy had left h. m. with global amnesia: Temporally graded retrograde amnesia: could not retrieve memories for events dating back to 11 years. Severe anterograde amnesia with almost no capacity to encode new semantic or episodic memories: other memory systems remained unaffected. Amnesia is global with respect to sensory modalities and materiality and thus distinguishes itself from being a perceptual, linguistic or other cognitive deficit. In addition to damaged mtl regions, amnesia results from lesions to the closely related diencephalic midline region, involving particularly the thalamic dorsomedial nucleus and the mammillary bodies of the hypothalamus.
