• Information
  1. Introduction
  2. Episodic Memory
  3. Semantic Memory
  4. Procedural Memory
  5. Working Memory

A. Introduction

1. Memory is collection of mental abilities dependent on several brain systems
2. Four major types of memory
   1. Episodic memory
   2. Semantic memory
   3. Procedural memory
   4. Working memory
3. Definitions
   1. Systems associated with conscious awareness are called "explicit"
   2. Consciously recalled memories are called "declarative"
   3. Systems associated with change in behavior are called "implicit"
   4. Unconsciously recalled memories are called "nondeclarative"
4. Other classification systems have been used

B. Episodic Memory

1. Remembering specific events or episodes such as:
   1. What the weather was like the day before yesterday
   2. What you had for breakfast in the morning
2. Major Anatomical Structures
   1. Medial temporal lobes
   2. Anterior or thalamic nucleus
   3. Mammillary Body
   4. Fornix
   5. Prefrontal cortex
3. Role of Brain Regions in Episodic Memory
   1. Lesions of frontal lobes can cause distortions of episodic memory
   2. Frontal lobe lesions also cause "false memories" including confabulations
   3. Frontal lobes are similar to a file clerk for episodic memories
   4. Medial temporal lobes are for recent memories
   5. Other cortical systems for remote memories
4. Length of Memory Storage: minutes to years
5. Type of Awareness: explicit, declarative
6. Diseases Prominently Impacting
   1. Alzheimer's Disease
   2. Dementia with Lewy Bodies
   3. Herpes simplex encephalitis
   4. Korsakoff's Syndrome
   5. Transient global amnesia
   6. Concussion / Traumatic Brain Injury (TBI)
   7. Seizure
   8. Cardiopulmonary Bypass
   9. Hypoxic-ischemic injury
   10. Vitamin B12 Deficiency
   11. Vascular dementia
   12. Multiple sclerosis

C. Semantic Memory

1. Factual memory, remembering specific facts
2. Major Anatomical Structures: inferolateral temporal lobes
3. Length of Memory Storage: minutes to years
4. Type of Awareness: explicit, declarative
5. Diseases Prominently Impacting
   1. Any disroder that disuprts inferolateral termporal lobes
   2. Herpes simplex encephalitis
   3. TBI

D. Procedural Memory

1. Examples (Table 1, Ref [1])
   1. Learning a sequence of numbers on a touch-tone phone without trying ("implicit")
   2. Driving a car with a standard transmission ("explicit")
2. Major Anatomical Structures
   1. Basal ganglia
   2. Cerebellum
   3. Supplementary motor area
3. Length of Memory Storage: minutes to years
4. Type of Awareness: explicit or implicit, nondeclarative
5. Diseases Prominently Impacting
   1. Parkinson's Disease
   2. Huntington's Disease
   3. Progressive supranuclear palsy
   4. Olivopontocerebellar degeneration
   5. Depression
   6. Obsessive compulsive disorder (OCD)

E. Working Memory

1. Examples (Table 1, Ref [1])
   1. Spatial: rotating an object in your mind
   2. Phonologic: keeping a phone number "in your head" before dialing
2. Major Anatomical Structures
   1. Phonologic: prefrontal cortex, Broca's and Wernicke's areas
   2. Spatial: prefrontal cortex, visual-association areas
3. Length of Memory Storage: seconds to minutes
4. Type of Awareness: explicit, declarative
5. Diseases Prominently Impacting
   1. Normal aging
   2. Vascular dementia
   3. Multiple sclerosis
   4. Alzheimer's Disease
   5. Dementia with Lewy Bodies
   6. Parkinson's Disease
   7. Huntington's Disease
   8. TBI
   9. Attention-Deficit Hyperactivity Disorder (ADHD)
   10. OCD
   11. Progressive Supranuclear Palsy
   12. Cardiopulmonary Bypass
   13. Schizophrenia
   14. Vitamin B12 Deficiency

References

1. Budson AE and Price BH. 2005. NEJM. 352(7):692