學(xué)習(xí)與記憶宏觀英文課件

1、Learning and Memory1. The basic concepts of learning&memory classification of learning&memory brain structures hosting learning&memory learning&memory in behavioral study learning&memory and neural plasticity2. The molecular basis of learning& memory studies in Aplysia studies in mouse, LTP, LTD and

2、 long term memoryBasic concepts of Learn&MemLearning：the process of acquiring ability or knowledge that is not born learned: reading;,writing, driving etc born: sucking milk, yelling, blinking etcMemory：the retaining/maintaining of learned ability or knowledgeActually, the studies on learning and me

3、mory include learning, repeating, memory, and forgetting as wellSteps of memory processingAcquisition is the process of bringing knowledge into the brain and into a first-stage memory buffer via sensory organs and primary sensory corticesConsolidation is the process of rehearsing and building a robu

4、st representation of it in the brainStorage is the creation of a relatively stable memory trace or record of knowledge in the brainRetrieval is the process of reactivating knowledge in a way that will allow it to become an image in consciousness or translated into motor outputAmnesiaRetrograde amnes

5、ia: memory loss for events before the trauma; you forget things you already knewAnterograde amnesia: an inability to form new memories following brain trauma.Classification of memoriesAccording to time course: Working memory Short term memory Long term memoryAccording to appearance: non-declarative

6、memory (implicit memory) declarative memory (explicit memory) Working memory: information held “in mind.”Short-term memory: memories that last on the order of seconds to hours and are vulnerable to disruption.Long-term memory: memories that you can recall days, months, or years after they were origi

7、nally stored.Implicit and explicit memoryNon-declarative memory (implicit memory): Perceptual memory: acquired through the sense. Procedure learning: representation of a series of actions or perceptual processing functions that occur unconsciously and repetitions typically result in increased speed

8、or accuracy Fear memory:Declarative memory (explicit memory): Episodic memory: a system that collects temporarily and spatially encoded events in a subjects life, such as recalls of particular experiences or episodes Semantic memory: an organization of factual information independent of specific epi

9、sodes during which that information was acquired.Its knowledge of the world.Declarative and non-declarativememory1. The basic concepts of learning&memory classification of learning&memory brain structures hosting learning&memory learning&memory in behavioral study learning&memory and neural plastici

10、tyBrain structures hosting learning&memoryGeneral theories about memory engramLocalization of declarative memory: temporal lobe diencephalonLocalization of procedure memory striatumLocalization of working memory frontal cortex The search for engram- Where is the engram?Engram- the physical represent

11、ation or location of memory, also called memory traceStrategy/Methods: 1. lesion or ablation of certain brain regions 2. recording the response of specific neuronsEffect of brain lesions on Maze learning in rats- Karl Lashleyrats given brain lesions before learning needed more trials to run the maze

12、 without going down blind alleysrat given brain lesions after learning made mistakes and went down blind alleys it had previously learned to avoid.a rat run through a maze to get foodThe greater the percentage of cortex destroyed, the more errors made while the rats learn to run the maze. The number

13、 of errors shown is cumulative across trials, suggesting that rats with larger lesions had difficulty remembering which arms of the maze were blind alleys.Karl Lashleys conclusionsall cortical areas contribute equally to learning and memory it is simply a matter of getting poorer performance on the

14、maze task as the lesion gets bigger and the ability to remember the maze worsens.It is wrong that all areas are equal, but it true that the memories are distributedBrain structures hosting learning&memoryGeneral theories about memory engramLocalization of declarative memory: medial temporal lobe die

15、ncephalon brainLocalization of procedure memory striatumLocalization of working memory frontal cortexLocalization of declarative memories to neocortexStudied in humanStudies in monkeysThe brain lesion in patient H.M. that produced severe anterograde amnesia.(a) The medial temporal lobe was removed f

16、rom both hemispheres in H.M.s brain to alleviate severe epileptic seizures. (b) A normal brain, showing the location of the hippocampus and cortex that were removed from H.M.sbrain.H.M. has partial retrograde amnesia for the years preceding the operation. Much more serious is his extreme anterograde

17、 amnesia. While he can remember a great deal about his childhood, he is unable to remember someone he met just a few minutes earlier.Case study- H.M.Declarative memories in neocortex -studies in monkeysResponses to faces in inferotemporal cortex. (a) The location of area IT in the inferior temporal

18、lobe of a macaque monkey. (b) Responses of a face cell.The histograms show the response of a neuron in area IT to different views of a monkeys head. The horizontal bar under each histogram indicates when the stimuluswas presented. (c) Changing responses of a cell to unfamiliar faces. Diencephalon an

19、d memoryComponents of the diencephalon involved in memory. The thalamus and mammillary bodies receive afferents from structures in the medial temporal lobe.Case study of NA and Kosakoffs syndromeCase study- N.A.The only obvious damage was a lesion in his left dorsomedial thalamus.N.A.s cognitive abi

20、lity was normal but his memory was impaired. He had relatively severe anterograde amnesia and retrograde amnesia for a period of about 2 years preceding the accident. While he could remember some faces and events from the years following his accident, even these memories were sketchy. He had difficu

21、lty watching television because during commercials, hed forget what was previously happening. Korsakoffs syndrome-lesions in the dorsomedial thalamus and mammillary bodiesNo strong correlation exists between the severity of anterograde amnesia and retrograde amnesia in Korsakoffs syndrome. The mecha

22、nisms involved in consolidation (disrupted in anterograde amnesia) are largely distinct from processes used to recall memories (disrupted in retrograde amnesia). Anterograde amnesia may be associated with diencephalic lesions results from damage to the thalamus and mammillary bodies. Retrograde amne

23、sia, may invovles diencephalon, the cerebellum, brain stem, and neocortex.Brain structures hosting learning&memoryGeneral theories about memory engramLocalization of declarative memory:Localization of procedure memory striatumLocalization of working memory An eight-arm radial arm maze. If a rat lear

24、ns that four of the eight arms never contain food, it will ignore these and follow a path to only thebaited arms.Hippocampus and declarative memoryTwo versions of radial arm maze task -declarative/procedure memoryThe first was the standard, in which the rat must move as efficiently as possible retri

25、eving the food from each of the baited arms of the maze.In the second version, small lights were illuminated above the arms containing food, and the unlit arms had no food. The lights could be turned on or off at any timeThe standard maze task was designed to require the use of declarative memory. T

26、he “l(fā)ight” version of the task was intended to draw on procedural memory because of the consistent association between the presence of food and illuminated lights.If the hippocampal system was damaged, performance was degraded on the standard maze task but was relatively unaffected on the light vers

27、ion.Conversely, a lesion in the striatum impaired performance of the light task but had little effect on the standard task. This “double dissociation” of the lesion site and the behavioral deficit suggests that the striatum is part of a procedural memory system but is not crucial for the formation o

28、f declarative memories.Brain structures hosting learning&memoryGeneral theories about memory engramLocalization of declarative memory: temporal lobe diencephalon brainLocalization of procedure memory striatumLocalization of working memory frontal cortex, area LIP Area LIP and working memoryLIP: late

29、ral intraparietal cortex (頂內(nèi)溝外側(cè)區(qū))(a) The monkey fixates on a central point while a peripheral target flashes on and off. When the fixation point disappears, and the animal knows to move its eyes to the remembered location of the target. (b) The histogram shows the response of an LIP neuron. 1. The b

30、asic concepts of learning&memory classification of learning&memory brain structures hosting learning&memory learning&memory in behavioral study learning&memory and neural plasticity2. The molecular basis of learning& memory studies in Aplysia studies in mouse, LTP, LTD and long term memoryNon-associ

31、ative learningSensitization progressive amplification of a response after repeated administrations of a stimulus Gill Withdraw Reflex in AplysiaHabituation decrease in response to a stimulus after repeated presentations Probscis extension response in Drosophila “wolf-coming” Associative learning- Classical conditioningCS: conditioned stimulus A signaling stimulus that does not elicit a response by itself US: unconditioned stimulus: A stimulus is a factor that causes a response in an organismConditioning: coupling of CS and US to elicit a responseAssociative learning-operant conditioningLe