Fundamentals of Human Neuropsychology, Sixth Edition Chapter 18 Lecture PPT

1. Bryan Kolb & Ian Q. Whishaw’s Fundamentals of Human Neuropsychology, Sixth Edition Chapter 18 Lecture PPT Prepared by Gina Mollet, Adams State College

2. Learning and Memory

3. Portrait: The Mystery of Memory • H.M. • Bilateral transection of the temporal lobes • After surgery, left with anterograde amnesia • Above average IQ • Good memory for events before the surgery, but unable to describe the job he has worked for 6 months • Spatial memory for his immediate surroundings

5. Learning and Memory • Amnesia • Partial or total loss of memory • Multiple Memory Systems • Different kinds of learning and memory use independent neural processes

6. Learning and Amnesia • Karl Lashley • Attempted to find the neural location of learning • Concluded that memory is represented in multiple regions • H.M. • Surgery that removed the medial temporal lobes • Case supports Lashley’s view

8. Varieties of Amnesia • Infantile Amnesia • Loss of memory for the early years of life • Fugue State • Form of memory loss where individuals have no knowledge of their former life • Transient Global Amnesia • Sudden onset and short course • Loss of old memories and inability to form new memories

9. Varieties of Amnesia • ECT • Treatment for depression • Can produce a transient amnesia • Restricted brain damage can produce specific amnesias • Amnesia for verbs, nouns, or animals

10. Varieties of Amnesia • Anterograde Amnesia • Inability to acquire new memories • Global Anterograde Amnesia • Impairment in the ability to form new memories across a variety of areas • Retrograde Amnesia • Inability to remember old memories

12. Varieties of Amnesia • Time-Dependent Retrograde Amnesia • Severity of injury determines how far back in time the amnesia extends

13. Theories of Retrograde Amnesia • Consolidation Theory • Role of the hippocampus is to consolidate memories and then send them to be stored elsewhere in the brain • Accounts for preservation of old memories • As more damage occurs, the more old memories will be lost

14. Theories of Retrograde Amnesia • Multiple-trace Theory • Three kinds of memory • Autobiographic memory • Factual semantic memory • General semantic memory • Each type is dependent on a different brain area • Old memories are more resistant to amnesia because they change location in the brain as they are recalled

15. Theories of Retrograde Amnesia • Reconsolidation Theory • Reconsolidation • A memory reenters a labile phase when it is recalled and is then restored as a new memory • Results in many different traces for the same event

16. Multiple Long-Term Memory Systems • Three types of long-term memories • Implicit Memories • Skills, conditioned reactions • Unconscious • “Bottom-up” processing

17. Multiple Long-Term Memory Systems • Three types of long-term memories • Explicit Memories • Events, facts and episodic memories • Conscious intentional remembering • “Top-down” processing • Emotional Memory • Memory for affective properties of stimuli • “Bottom-up” and “Top-down” processing

18. Implicit Memory • H.M. • Able to learn to complete a task, yet has no memory of ever having performed the test

19. Sparing of Implicit Memory • Priming • Stimulus is used to sensitize the nervous system to a later presentation of the same stimulus • The Gollin Incomplete Figures Test • Implicit and explicit memory are independent of each other • Depth-of-processing effect • Study-test modality shift

21. Impairments in Implicit Memory • J.K. • Implicit memory deficits • Forgot how to turn on lights • Preserved memory for events and new experiences

22. Explicit Memory • Autobiographic or Episodic Memory • Singular events a person recalls • Memory of life experiences • Autonoetic Awareness of Time • Self-knowledge • K.C. • Cannot remember any specific events across his life or imagine the future • Can remember objective facts

23. Explicit Memory • Autonoetic Awareness of Time • M.L. • Amnesic for episodic events before his injury • Damage to the right ventral frontal cortex, uncinate fasciculus (connects the temporal and frontal lobes) and ventral frontal cortex

26. Explicit Memory • Semantic Memory • Knowledge about the world • Intact in H.M. and K.C.

27. Neural Substrates of Explicit Memory • Petri and Mishkin • Temporal-frontal-lobe neural basis for explicit memory

28. Anatomy of the Hippocampus

29. Anatomy of the Hippocampus • Granule Cells • Stellate cells of the dentate gyrus • “Sensory” cells • Pyramidal Cells • Cells of Ammon’s horn • “Motor” cells

30. Anatomy of the Hippocampus • Perforant Pathway • Connection between the hippocampus and the posterior neocortex • Fimbria-fornix • Connects the hippocampus to the thalamus, frontal cortex, basal ganglia, and the hypothalamus

31. Case Histories of Hippocampal Function • R.B. and D.G. • Lesions to the CA1 region • Limited retrograde amnesia • L.M. and W.H. • Incomplete hippocampal damage • Retrograde amnesia covering 15-25 years

32. Case Histories of Hippocampal Function • E.P. • Complete hippocampal damage and damage to surrounding structures • Retrograde amnesia covering 40-50 years • V.C. • Complete removal of the hippocampus • Complete retrograde and anterograde amnesia for explicit information

33. Early Hippocampal Damage • Early damage leads to the inability to remember: • Familiar surroundings or where objects are located • Appointments or events • Daily activities • However, can remember: • Factual knowledge • How to read, write, and speak

34. Neural Connections to the Hippocampus • Damage to the fimbria-fornix pathway • Retrograde and anterograde amnesia • Damage to the temporal stem • Contributes to amnesia • Severing of connections between the posterior neocortex and the temporal lobe • May produce amnesia

35. Damage to the Hippocampus • Studies of hippocampal patients demonstrate four conclusions: • Anterograde deficits are more severe • Episodic memories are more affected than semantic memories • Autobiographic memory is especially affected • Patients cannot time travel to the past or future

36. The Perirhinal Cortex • Rhinal cortex • Cortex that surrounds the rhinal fissure • Includes the entorhinal and perirhinal cortex • Projects to the hippocampus

38. The Perirhinal Cortex • Elisabeth Murray • Produces selective damage to the hippocampus or the rhinal cortex • Examines object recognition and object recognition in a given context

40. The Perirhinal Cortex • Elisabeth Murray • Damage to the hippocampus produces impairment when the task includes context • Damage to the rhinal cortex produces impairments on object recognition

41. Hemispheric Specialization for Explicit Memory • Right Temporal Cortex • Removal leads to deficits on face recognition, spatial position, and maze learning • Left Temporal Cortex • Removal leads to deficits in recall of word lists, recall of consonant trigrams, nonspatial associations, and on the Hebb Recurring-Digits test

42. Maze Learning

44. Hemispheric Specialization for Explicit Memory • Parietal and Occipital Cortex • Injuries may produce color amnesia, prosopagnosia, object anomia, and topographic amnesia • Frontal Cortex • Left Prefrontal Cortex • Encodes semantic and episodic information • Right Prefrontal Cortex • Retrieves episodic information

45. HERA

46. Diffuse Damage and Explicit Memory • Herpes Simplex Encephalitis • Medial temporal lobe damage leads to anterograde amnesia • Damage to the insula produces retrograde amnesia

48. Diffuse Damage and Explicit Memory • Alzheimer’s Disease • Begins with cellular change in the medial temporal cortex and anterograde amnesia • Later damage to the temporal association areas and frontal cortical areas is related to retrograde amnesia

49. Diffuse Damage and Explicit Memory • Korsakoff’s Syndrome • Characterized by: • Anterograde amnesia • Retrograde amnesia • Confabulation • Meager content in conversation • Lack of insight • Apathy • Caused by a thiamine (vitamin B1) deficiency • Damage may be in the medial thalamus, mammillary bodies of the hypothalamus, and general atrophy

50. Ascending Systems Critical for Explicit Memory • Cholinergic, serotoninergic, and noradrenergic systems may be involved in memory