12 Memory Systems

1. 12 Memory Systems Psychology 355

2. Introduction • Learning and remembering distinguishes naïve from mature brain • Relationship between visual development and learning • Similar mechanisms in different cortical areas • Memories range from stated facts to ingrained motor patterns • Anatomy: Several memory systems • Evident from brain lesions Psychology 355

3. Learning & Memory Learning Acquisition of new information Memory Retention of learned information Psychology 355

4. Sensory information Short-term memory Consolidation Long-term memory Short-term memory Sensory information Consolidation Long-term memory Time Types of Memory • Long-Term, Short-Term, and Working Memory Working memory: Active, Temporary information storage Psychology 355

5. Types of Memory: Long-Term Declarative memory (explicit) Facts and events Nondeclarative memory (implicit) Procedural memory- skills, habits, behaviors Psychology 355

6. Types of Memory and Amnesia Amnesia: Serious loss of memory and ability to learn Causes: Concussion, chronic alcoholism, encephalitis, hypoxia, brain tumor, or stroke • Limited amnesia • Dissociated amnesia: Amnesia, no other cognitive deficit (rare) • Anterograde with Temporally-Graded Retrograde Amnesia • Transient global amnesia:Caused by ischemic episode. Short duration Symptoms: Disoriented, ask same questions repeatedly; Attacks subside in couple of hours; Permanent memory gap Psychology 355

7. Types of Memory and Amnesia Memory loss related to time • Retrograde amnesia Forget things you already knew • Anterograde amnesia Inability to form new memories Psychology 355

8. Memory Storage Psychology 355

9. Memory Storage • Hebb and the Cell Assembly • External events are represented by cortical cells • Cells reciprocally interconnected reverberation • Active neurons—cell assembly • Consolidation by “growth process” • “Fire together, wire together” • Hebb and the engram • Widely distributed among linked cells in the assembly • Could involve neurons involved in sensation and perception Psychology 355

10. Memory Storage Hebb’s Cell Assembly and Memory Storage Psychology 355

11. Memory Storage • Localization of Declarative Memories in the Neocortex • Experiments—macaque monkeys • Differentiate objects based on shapes • Lesion made in area IT • Cannot discriminate • Does not remember stimulus • Studies in humans Psychology 355

12. Memory Storage • Electrical Stimulation of the Human Temporal Lobes • Penfield’s experiments • Electrical stimulation of the temporal lobe Complex sensations • Penfield’s patients: Sensations like hallucinations, recall past experiences • Temporal lobe: Role in memory storage • Temporal lobe stimulation • Different from stimulation of other areas of neocortex Psychology 355

13. The Temporal Lobes and Declarative Memory Temporal Lobectomy Psychology 355

14. The Temporal Lobes and Declarative Memory The Medial Temporal Lobes and Memory Processing Psychology 355

15. The Temporal Lobes and Declarative Memory The Medial Temporal Lobes and Memory Processing Psychology 355

16. The Temporal Lobes and Declarative Memory DNMS: Delayed non-match to sample Psychology 355

17. The Temporal Lobes and Declarative Memory DNMS: Delayed non-match to sample Psychology 355

18. The Temporal Lobes and Declarative Memory The Diencephalon & Memory Processing Psychology 355

19. The Temporal Lobes and Declarative Memory The Diencephalon: Korsakoff’s Syndrome • Symptoms: Confusion, confabulations, severe memory impairment, and apathy • Alcoholics: Develop thiamin deficiency • Leads to symptoms: Abnormal eye movements, loss of coordination, tremors • Treatment: Supplemental thiamin • Thiamin deficiency: Structural brain damage Psychology 355

20. The Temporal Lobes and Declarative Memory Role of the medial temporal lobes Psychology 355

21. The Temporal Lobes and Declarative Memory Morris water maze Psychology 355

22. The Temporal Lobes and Declarative Memory Relational memory: Spatial Navigation Extra-Maze Cues Psychology 355

23. The Temporal Lobes and Declarative Memory Relational memory: Spatial Navigation Psychology 355

24. The Temporal Lobes and Declarative Memory Relational memory: Transverse Patterning A>B B>C C>A Transitive Inference A>B B>C C>D D>E B?D Psychology 355

25. The Striatum & Procedural Memory • Two elements of basal ganglia Striatum • Caudate nucleus • Putamen • Rodent Recordings and Lesions in the Striatum • Lesions to striatum: Disrupts procedural memory • Damaged hippocampal system: Degraded performance on standard maze task • Lesion in striatum: Impaired performance of the light task; Double dissociation Psychology 355

26. The Striatum & Procedural Memory Psychology 355

27. Working Memory The Prefrontal Cortex and Working Memory Function of prefrontal cortex: self-awareness, capacity for planning and problem solving Psychology 355

28. Working Memory Imaging Working Memory in the Human Brain Numerous areas in prefrontal cortex are involved in working memory Face Only Face & Spatial Spatial Only Psychology 355

29. Working Memory Working Memory • Updating • Perseveration Psychology 355

30. The Working Memory Lateral Intraparietal Cortex (Area LIP) and Working Memory: Guiding eye movements Delayed-saccade task Psychology 355

31. Concluding Remarks • Learning and memory • Occur throughout the brain • Memories • Duration, kind of information stored, and brain structures involved • Distinct types of memory • Different types of amnesia • Multiple brain systems for memory storage • Engrams in temporal lobe neocortex • Physiological basis? • Long-term memories: structural basis? Psychology 355

32. End of Presentation Psychology 355