Presentation on theme: "Unit 3 – Area of study 2: Memory"— Presentation transcript:
1 Unit 3 – Area of study 2: Memory Chapter 6: Memory
2 Study design, 2010 - 2014 This knowledge includes: Comparison of models for explaining human memory:Atkinson-Shiffrin’s multi-store model of memory including maintenance and elaborative rehearsal, serial position effect and chunkingAlan Baddeley and Graham Hitch’s model of working memory: central executive, phonological loop, visuo-spatial sketchpad, episodic bufferlevels of processing as informed by Fergus Craik and Robert Lockhartorganisation of long-term memory including declarative and episodic memory, and semantic network theoryNeural basis of memory:role of the neuron in memory formation informed by the work of E. Richard Kandelroles of the hippocampus and temporal lobeconsolidation theorymemory decline over the lifespanamnesia resulting from brain trauma and neurodegenerative diseases including dementia and Alzheimer’s diseaseStudy design,
3 Unit 3 – Area of study 2: Memory Assessment tasks S/N Work RequirementsGlossary – due 15th May, 2012Workbook which includes the learning activities from textbook as per the slides and completed activities/tasks given by your teacher (Min. 80% complete) – due 15th May, or earlier90% attendance rateSACsERAWeek 3 (approx.)/30 marksTestWeek 8 (approx.)/20 marksNoteIf you are away during a SAC – you MUST hand in an original medical certificate in order to re sit the SAC.This is a VCCA requirement, and parents or students who only phone or do not satisfy this requirement, and if a medical certificate is not produced, a score of 0 will be given
4 Chapter 6 – What’s coming up? Defining memoryModels for explaining human memoryThe Atkinson-Shiffrin multi store modelSensory memoryShort term memoryCraik & Lockharts levels of processing frameworkBraddeley & Hitch’s model of working memoryLong Term memorySerial position effectNeural basis of memoryRole of the neuron in memory formationRole of hippocampus & temporal lobeconsolidation theoryAmnesia resulting from brain trauma & neurodegenerative diseasesMemory decline over the lifespan
7 Processing different information retrieving the information Memory is not a ‘single organ’ or a single ‘thing’, rather it consists of a collection of complex interconnected and interacting systemsWe do not have a memory, but we have different memory systems which share a common function of:our perceptual systems, eg vision are constantly inputting information, however the brain must work out what to attend to, process and store in memory, and what not to!storing information(learned through experience)Processing different informationMemory systemsretrieving the information(when needed)Storing information(in different ways & types of information)
8 Defining memoryMemory is often defined as the storage and retrieval of information acquired through learning.the existence of memory indicates that learning has occurred and the memory is the internal record or representation of an event &/or experience.Memory is also defined as requiring and as information processing (think… like a computer)Memory as information processing -Encoding – converting information to a useable formStorage – retaining information in memoryRetrieval – information recovered from memory when neededAll three processes are required and if any one is not included, the memory will not form. (see fig 6.4 on page 291)
9 Memory as an info-processing system Memory is an active (uses energy) information-processing system that:Receives,OrganisesStores &recovers informationMemory actively alters and organises information, then stores it so that it can be easily retrieved when neededThere are 3 key processes involved in these systems. If any of these processes fail, memory will failAn additional aspect of the Atkinson & Shiffrin human multi store model included:Structural features & Control processes.Incoming sensory inputInfo is converted for storageEncodingInfo is retained in brainStorageInfo is recovered when neededRetrieval
10 Memory like a computer ????= hitting the letters on the key board -> it goes into the computer= we hit ‘save’ -> we name the file and store the information for later on when we save the file= process of getting past information back -> we need to use the right ‘cues’ in order to get the information back, but if we do then we have the original information back!EncodingStorageRetrieval
11 Read box 6.3 – on p 291-292 Automatic & effortful encoding Encoding can be spilt further into categories.read, define & provide and example of automatic encoding & effortful encoding
12 Page 292 of your text, Questions 1,2 & 3 Learning Activity 6.2Page 292 of your text, Questions 1,2 & 3
13 Model’s for explaining human memory As the human memory is complex and multifaceted, is it NOT studied together, rather it is broken down into pieces or sections, each being studied separately.Each of these is referred to as a MODELThe three main theories that explain how human memory functions are:Atkinson-Shiffrin multi-store modelBaddeley and Hitch’s model of working memoryCraik and Lockhart’s levels of processing framework
14 Atkinson-Shiffrin’s multi-store model of memory Based in the 1960’sProposed a shift in the single memory model => assumption that human memory has several systems/processes involved.By Richard Atkinson & Richard Shiffrin – Americans.This model was also called/considered modal model, as it merged and represented many other models during this time.It is also known as the stage model, as it put forward that the flow of information moves in stages through each component of memory.Information passes through 3 levels of memory as it is encoded, stored and retrieved, and these 3 levels are sensory register, short term store & long term store
15 Sensory register Short term store Long term store The entry point for all new information into memory from the external environmentStores vast amount of incoming visual information, for 100’s millisecondsRehearsal at time point critical for more permanent storage (LTM)If information is attended to, it moves into short term memory storeIf information is not attended to, it is lostShort term storeA temporary working memoryHere we can manipulate information from every day/common tasksHolds all information that we are aware of at that point in timeHas a limited capacity – 7 items at 1 timeOnly held for about 30 sec unless we make an effort to keep it there (attend to it), eg rehearsalLong term storeInformation held relatively permanently in an highly organised wayEssentially can be an unlimited capacityUnlike sensory register & short term store – information in long term store does not usually decay and can stored for …… a whole lifetimeAccording to Atkinson & Shiffrin – it is our inability to retrieve required information that results ineffective search strategiesProblems with retrieval may also be due to ‘interference’ with the information and this results in a disruption in the retrieval process
16 Atkinson-Shiffrin multi-store model RehearsalPaid attention to infoInfo encoded or rehearsedSensory MemoryShort-term MemoryLong-term MemorySensory infoRetrievalInfo not paid attention to…Not rehearsed or encodedVarious reasonsLost from sensory memoryDisplaced from short-term memoryForgottenCRIMD
17 Structural & controlled processes Structural features of memory are the permanent features that do not alter from situation to situation – they are three levels of information processing:Sensory memory,Short term memory (STM) &Long term memory (LTM)Control processes are the activities the individual does to process the information (eg they have ‘control’ over what they attended to and process)Attention – no information will be encoded if we don’t pay attention to itRehearsal – process that goes over information and helps it be storedBut all of this was developed over 40 years ago ….. And we know have more knowledge …
18 Evaluating Atkinson & Shiffrin AdvantagesLimitationsIdentified characteristics of short term store as being different and apart from long term memoryRecognised the importance of short term store & its fundamental rolesManitence and rehearsal are still relevant, although now more complexDespite some newly learnt differences, still held as the original multi store model, although now just more complexIt is now clear that information does not ‘just flow’ as described in Atkinson & Shiffrin’ 3 stage sequenceThere is a separate sensory register for auditory information & haptic (touch) information – and maybe even more now referred to as a sensory memory systemShort term store now believed to be a much more complex systemDifferent types of rehearsal have been identified in short term memoryLong term store is no longer a single store -> rather it includes more complex systems & structures of storage.
19 Page 295 of your text, Questions 1-7 Learning Activity 6.3Page 295 of your text, Questions 1-7
20 Stages of memory – Sensory Memory Entry point of memoryCapacity to store all sensory stimuli (unlimited)Stored as the original form of stimulus (buffer – need more processing before it can be stored)Not consciously aware of most of the info in sensory stage, directing attention to it is what causes transfer to short-term memoryIncoming stimuli is stored as a memory trace in different sensory registers based on the type of senseIconic memory – visualEchoic memory - auditory
21 Sensory Memory includes Iconic memory ( I as in eye)Visual images are stored here for about secondsStored as overlapping imagesAllows perception of flowing movement during a film, or a figure drawn with a sparkler at nightEchoic memory (e as in ear)Sound stimuli are stored here for around 3-4 secondsThis is longer than in iconic memory as sound takes longer to produceAllows comprehension of speech by connecting individual sounds coherently into words and sentences
22 Page 299 of your text, Questions 1-7 Learning Activity 6.5Page 299 of your text, Questions 1-7Note: there is also an interesting read in Box 6.4 on photographic memory
23 Stages of memory – Short-term memory Activity: Capacity of STMRead aloud the following series of numbers and ask students to recall each line in order.6, 4, 7 (3 items)9, 0, 1, 8 (4 items)4, 3, 5, 7, 2 (5 items)7, 1, 3, 8, 9, 4 (6 items)3, 6, 8, 4, 9, 1, 5 (7 items)2, 6, 4, 9, 1, 5, 7, 3 (8 items)1, 7, 5, 8, 6, 3, 9, 2, 4 (9 items)2, 6, 7, 3, 5, 4, 9, 1, 8, 3 (10 items)On average, how many numbers did each person recall from each list? This is the capacity of STM.Activity: Duration of STMStudents learn the following sequence of numbers4, 5, 3, 6, 2, 7, 8Test immediately, then after 2 minutesHow many people remembered the sequence? This is duration of STM
24 Stages of memory: Short-term memory Short-term memory (STM) is a memory system that has a limited capacity and durationIt also stores the information in an encoded formatDescribed as the “seat of conscious thought” – information only registers in STM once it is paid attention to – in conscious awarenessDuration of STMWithout rehearsal (active use), recall starts to decline after about 12 seconds and is almost completely gone after 18 seconds (occasionally can last up to 30 sec)Using rehearsal, information can be retained indefinitely in STM
25 Page 307 of your text, Questions 1-7, don’t worry about Q 8. Learning Activity 6. 7Page 307 of your text, Questions 1-7, don’t worry about Q 8.
26 Short-term memory Capacity of STM The amount of pieces of information that can be stored in STM is 7 ± 2 (between 5-9 items)Adding in more items displaces (pushes out) existing items in STM – this is called displacement, shown belowRecalling information from long-term memory can also displace items from STMInformation is lost primarily within STM by either displacement (pushing out) or by decay (not being used- think fruit!)Now becomes ..
27 Short term memory Capacity of STM cont….. Chunking is a method of increasing the capacity of STMDefiniton: grouping or separate bits of information into a larger single chunk of information.Separate pieces of info are remembered as single units (groups info into chunks)Only similar info can be chunked together (chunking)Still only retain 7 ± 2 chunksChunks can be numbers, images, words, sentences, phrases and even abbreviationsThis is why we have phone numbers broken into parts …… rather than
28 Short term memory STM as working memory Term working memory is used to emphasise the active part of memory where information we are aware of constantly, is actively ‘worked on; in a variety of waysEnables us to use the information in sensory memory and move it to LTMOften we combine information from sensory memory and LTM to perform mental processes, such as emotions, comprehension, problem solving, planning & daydreaming.So this ‘working memory’ provides a temporary storage facility and mental workspace for information currently being used within a conscious cognitive activity.The STM working memory is often compared to a computer
29 Effects of rehearsalRehearsal is the process of actively and consciously manipulating information to keep it in STM for longer than the normal 18 sec. (Increases duration)Maintenance rehearsalRepeating info over and over usually vocally (out loud) or sub- vocally (in your head)Works indefinitely to keep info in STMDoes not always transfer info into long-term memoryElaborate rehearsalLinks new info to existing knowledge in a meaningful wayMore active than maintenance rehearsal (requires more effort)Very effective in transferring info into long-term memory, especially when using personal link (self-reference effect)
30 Effects of rehearsal Maintenance Rehearsal Elaborative Rehearsal Paid attention to infoSensory MemoryShort-term MemoryLong-term MemorySensory infoRetrievalInfo not paid attention to…Not rehearsed or encodedVarious reasonsLost from sensory memoryDisplaced from short-term memoryForgottenCRIMD
31 Page 312 – we can do this one as a class! Learning Activity 6. 10Page 312 – we can do this one as a class!
32 Stages of memory – Long-term memory Long-term memory (LTM) is the relatively permanent memory system that has potentially unlimited capacity and duration (life-long)Info in LTM is inactive (not in use) and we are not consciously aware of it until it is retrievedDue to the sheer volume of info in LTM, we use cues (intentional or unintentional) to speed up the process of retrievalCues enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fastOnce retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTMFailure to retrieve info from LTM is usually due to poor organisation during encoding and storage, or an inappropriate cue was used during retrievalInfo is encoded in terms of its meaning (semantically)
33 Types of long-term memory Memories in LTM are relatively permanent or at least very longlastingForgetting is most likely due to a failure to retrieve info – poor encoding or poor cueRetrieval cues: a stimulus that assists in the process of locating and retrieving information stored in memory.There are two major types of LTM (LTM stores):Procedural memory (Implicit memories – “how?”)Knowing how to do stuff – actions and activitiesOften difficult to explain this knowledgeUsually learnt through observation and practiceNot usually consciously recalledE.g. making a cup of tea/riding a bike
34 Types of long-term memory Declarative memory (Explicit memories – “What?”)Memories of facts and/or eventsUsually consciously recalledTwo types of declarative memory:Episodic memoryMemories of specific events or personal experiencesInclude references to “when” and “where”Semantic memoryMemories of general academic knowledgeFacts not necessarily related to a specific place or timeInclude references about “what” and “who”
35 Characteristics of the stages of memory Stage of memoryFunctionForm of storageCapacityDurationSensory memory (SM)Receives sensory information (stimuli) from environmentOriginal sensory formE.g. lingering sense of sound or pressureUnlimitedVaries based on sensationUsually between 0.2 – 4 secOccasionally up to 10 secShort-term memory (STM)Receives info from SMReceives info from LTMEncoded in terms of physical properties of stimuliE.g. Starts with L7 ±2 pieces or chunks of infoUsually secOccasionally up to 30 secLong-term memory (LTM)Storehouse for encoded info coming from STMEncoded in terms of semantics - meaningPotentially permanent
36 Levels of processing framework – Craik and Lockhart Craik and Lockhart proposed a framework of memory that emphasised the importance of the level of processing in how well information is stored in LTMInfo is stored best in LTM semantically (by meaning) so if the meanings of concepts are processes during learning, they are more likely to be recalled later – elaborate rehearsal is more effective for LTM than maintenance rehearsalThe deeper the level of processing (more elaborate encoding) the better the recallVisual encoding – “is there a letter k in the word?”Acoustic encoding – “does it rhyme with hat?”Semantic encoding – “is it a synonym of difficult?”
37 Levels of processing framework Levels of processing or depth are hard to define specifically and to measureDespite this problem the idea of better processing and therefore better storage is supported widely by researchCraik and LockhartShallow processingVisual encodingWhat the word looks likeColours, shapes and patterns detectedIntermediate processingAcoustic encodingWhat the word sounds likeItem is identifiedDeep processingSemantic encodingWhat the word meansMeaningful associations are made
38 Model of working memory – Baddeley and Hitch’s Baddeley and Hitch’s model of working memory describes STM as a functional system with three components that work independently but can also interact:Phonological loop (Verbal working memory)Verbal information is stored in a sound-based form (phonological)Only hold about 2 sec worth of info (around 7 items depending on length of words)Visuo-spatial sketchpad (Visual working memory)Visual info is anything you can see or imagine, spatial info is position and location of objects in spaceAlso has limited duration and capacity (around 4 items)
39 Model of working memory – Baddeley and Hitch’s Central executiveControls attentionIntegrates information from the phonological loop and visuo-spatial sketchpad with info from LTMCoordinates the flow of info between the working memory system and LTMManipulates the info held in the phonological loops and visuo-spatial sketchpad – the working component of the model of working memoryEpisodic buffer (a fourth component added in 2000)A sub-system of the working memory that enables the different components to interact with LTMHas limited capacity (about 4 chunks of info)Can hold info in any form and so can integrate phonological loop and visuo-spatial sketchpad – temporary workspace where various pieces of info can be put together in a meaningful wayControlled by central executive
40 Model of working memory Sensory inputRehearsalRehearsalPhonological loopVisuo-spatial sketchpadCentral ExecutiveEpisodic BufferLong-Term Memory
41 Alan Baddeley and Graham Hitch’s model of working memory Visio spatial SketchpadStorage of visual and spatial informationPhonological Loopstorage of verbal speech informationEpisodic BufferIntegrates useful LTM into what currently being worked onPulls together streams of different info into ‘episodes’ as a meaningful wholeThe workbenchCentral ExecutiveControls attentionIntegrates info from the two storage sub systemsdoes the ‘working out’The seat of consciousness
42 Baddeley & Hitch’s model of working memory Read example on pg. 319Once we have read it .....Going to party the following is:phonological loop stores the directionsVisio spatial sketchpad visualises the routeCentral executive directs the Episodic buffer to combine information from storage branchesEpisodic buffer also adds information from LTMEpisodic buffer used as the mental ‘workbench’ to make adjustments
44 Again … just in cases you need to refresh Stages of memory – Long-term memory Long-term memory (LTM) is the relatively permanent memory system that has potentially unlimited capacity and duration (life-long)Info in LTM is inactive (not in use) and we are not consciously aware of it until it is retrievedDue to the sheer volume of info in LTM, we use cues (intentional or unintentional) to speed up the process of retrievalCues ( retrieval cues) enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fastOnce retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTMFailure to retrieve info from LTM is usually due to poor Organisation during encoding and storage, or an inappropriate cue was used during retrievalInfo is encoded in terms of its meaning (semantically)
45 Types of long-term memory Memories in LTM are relatively permanent or at least very longlastingForgetting is most likely due to a failure to retrieve info – poor encoding or poor cueThere are two major types of LTM (LTM stores):Procedural memory (Implicit memories – “how?”)Knowing how to do stuff – actions and activitiesOften difficult to explain this knowledgeUsually learnt through observation and practiceNot usually consciously recalledE.g. making a cup of tea/riding a bike
46 Types of long-term memory Declarative memory (Explicit memories – “What?”)Memories of facts and/or eventsUsually consciously recalledTwo types of declarative memory:Episodic memoryMemories of specific events or personal experiencesInclude references to “when” and “where”Semantic memoryMemories of general academic knowledgeFacts not necessarily related to a specific place or timeInclude references about “what” and “who”
47 Tulving (1983)Tulving argues that semantic & episodic memory systems often work together in forming new memories – it isn't always one or the other.In such instances, the memory that ultimately forms may consist of an autobiographical episode and semantic information.
48 Types of long-term memory Complete the table in your workbooksTypes of Long Term MemoriesProcedural MemoriesDefinition:Example:Declarative MemoriesEpisodic MemorySemantic Memory
50 Organisation of Information in LTM Long term memory’s most distinctive feature is its organisation of informationThe task of retrieving information from LTM differs from the process of retrieving information from STM.In short term memory, the search and retrieve tasks involve scanning only items to locate the relevant information.This system doesn’t work with LTM, as there is such vast information to store, so there is a need for organisation to assist the storage and retrieval process.
51 Bousfield & Bower & Clark Research into LTM has been studied for over 65 years now. Research suggests:Bousfeild & Sedgewick, 1944Information may be recalled in burst of information, pause briefly ….. Then recall more information and so forth.This suggested the way people recalled items reflected the way the items were organised in LTMBousfeild, 1953Noticed that when asked to recall information, people would recall the words in groups or clusters, without being awareHockenbury & Hockenbury, 2006It is still believed today that there is some kind of logical association in LTMBower & Clark, 1969Found that words that were memorised in stories would recall up to 90% of 12 words compared to only 15% of words remembered in any orderThey concluded that the results from recall in LTM were improved using some organisation method.
52 Page 327 questions 1 – 10 These are great exam practice questions ! Learning Activity 6. 19Page 327 questions 1 – 10These are great exam practice questions !
53 Semantic network theory Information is stored in LTM as series of overlapping networksEach network is interconnected by meaningful linksEach item of information or concept in the network is called a nodeWhen a node in a network is activated (retrieved) all other related nodes are made available (easier to retrieve) – spreading activationLinking multiple concepts removes the need for multiple copies of the same informationThe shorter or thicker the link between nodes, the stronger the association between them and the faster the retrievalThink of the semantic network theory as towns as nodes and the highways & streets as links
56 Learning Activity 6. 21 Page 330 questions 1 – 2 ONLY These are great exam practice questions !
57 Serial position effect The serial position effect describes the differences in ability to recall items in a list depending on their position in that listFor immediate recall, typically items at the end of the list are best recalled, then items at the start of the list, with items in the middle of the list least likely to be recalledRecency effectSuperior recall of items at the end of the list (most recently experienced)Still in STM so easy to retrievePrimacy effectSuperior recall of items at the start of the listHad the most time to rehearse for probably retrieved from LTMItems from the middle of the list are no longer in STM and haven’t had a chance to make LTM, so least likely to be recalledMost clearly shown when tested immediately after exposure to the list. After 30 seconds recency effect is less apparent
58 Serial Position Effect Glanzer & Cuntiz (1966) research concluded that the STM & LTM must work together within the serial position effect. This was due recall better at both the start and end of the list, but with a delay of 30 seconds, this is beyond the limits of STM, and items at the start of the list were more likely stored in LTM.
60 Neuron bases of memoryMemories are stored throughout the brain linked together by memory traces or “circuits” – interconnected neuronsHowever, different parts of the brain are involved in memory formation and retrieval to different degrees, and in different types of memoriesNew memories (either short or long term) are NOT stored in individual synapses but in the pattern of thousands of new interrelated connectionsLooking for memories in a single nerve cell or synapse is a dead endWe know that there is a molecular basis to memory formation, what we do not know is exactly how thousands of these new connections hold our memories.
61 Kandels sea slugs Read pages 335 – 336 Kandel identified that there are physical changes to neurons during the formation of new memoriesWorked primarily with large sea slugs (Aplysia californica)Has very simple Nervous System20, 000 neuronsLargest observable neurons – can be seen with the naked eye!
62 This suggest some kind of LTM lasting days or even weeks Stimulated the siphon (gill in the tail of slug that squirts water to move slug away from danger)According to Kendal:STM – would withdraw gill more and more quicklyForgetting – an hour later the withdrawal was again slow, progressively faster with continued stimulationHabituation – eventually the slug stopped responding to the stimulation as it caused no damage, it had ‘learned’ that the shock was harmlessRetraction of the gills changes over time indicating memory, so Each day the slug would habituate more quickly than the day beforeThis suggest some kind of LTM lasting days or even weeksBy studying the neurons involved in this process he identified the changes that allowed the learning to take placeThe neurons were physically changing!These changes are called collectively Long Term Potentiation
63 Long Term Potentiation Neural basis for memory formationSynapse strength can increase in 3 waysRelease extra neurotransmitterIncrease number of receptor sitesGrowth of new synapses
64 Long Term Poteniation – Explicit STM New Receptor FormationStronger neural impulse in post synaptic neuron
65 So, we know all from sea slugs …….. Changes to neurons during memory formation are collectively called Long-term potentiation and include:Increased volume of neurotransmitter (function)Increased connectivity to other neurons (structure)Increased number of branches (dendritic spines) at the dendrite and/or axon terminal ends – reinforce existing connectionsNew synaptic junctions are formed between neurons – creating new memory traces /neural pathwaysShort-term memory storage only tends to increase neurotransmitter production, while long-term storage produces functional and structural changesAs a memory is recalled, all the neurons in the memory trace are activated in sequence. The strength and number of connections between each neuron increases the ease and speed of recall
67 Hippocampus & Temporal lobe The hippocampus is a curved structure found in each of the lower temporal lobes – one in each hemisphere (think horseshoes!)Its about 3.5cm long and in humans have one in each of the lower region of the temporal lobeCorpus callosumThalamusAmygdala
69 The Hippocampus & Medial Temporal Lobe – damage and memory Henry Molaison (H.M.) was a split brain patient who also had his medial temporal lobe (inner surface area towards the temporal lobe that includes hippocampus & amygdala) removed to stop his extremely severe epilepsyMedical success in preventing seizures, however it affected his memoryHis personality and basic functioning remained unchanged, however he suffered major memory impairment, and left with permanent anterograde amnesia (Can’t form new LTM’s)Eg. While he could remember events from before his surgery, he couldn’t remember anything that occurred after his surgery – couldn’t form new long-term memoriesOther mental abilities and STM fineEg. He could retain info in STM as long as he maintained attention and actively rehearsed it, but could not transfer it into LTM
70 H.M’s Hippocampus & Medial Temporal Lobe – damage & memory This established that the hippocampus and medial temporal lobe are involved or has a role in LTM formation,It is NOT the storage site of long-term memories howeverEvidence that LTM is most definitely a distinct sub system of memory (STM fine)This demonstrated that the hippocampus & medial temporal lobe has an important role in the formation or encoding of new declarative explicit memories (semantic & episodic), but not in the formation & retrieval of implicit memories (procedural)
71 Consolidation TheoryInformation that is transferred from STM to LTM needs a period of time to be properly and permanently encoded and stored – (‘consolidated’ or set - think concrete!)The consolidation theory suggests that there are structural/physical changes to the neurons (long-term potentiation & axon growth) as new memories are formed.These changes take time (consolidation phase) and the memory can be interfered with (changed) or erased (lost permanently) during this time.The new memory is vulnerable for at least 30 minutes after being experienced.The hippocampus and medial temporal lobe play an important role in consolidationReconsolidation is the process of returning information back to LTM after it has been retrieved and used – the memory may be altered in this time.
72 Consolidation – Rats in a maze Hudspeth, mccaught & thompson, 1964 The researchThe ResultsRats learned to run a maze to find a food reward4 groupsA – ECT immediatelyB – ECT 20 seconds afterC – ECT 30 minutes afterD – ECT 60 minutes afterA – all rats forgot completelyB – partial recallC – partial recall (better than B)D – total recallConsolidation seems complete after about 1 hour
73 Linking Consolidation theory & H.M It has been proposed that the hippocampus acts as a kind of memory formation area where the brain temporarily holds & processes the components of the info to be remembered e.g. sounds, location, images etc.All of these components of the information need to be integrated or linked together, in the hippocampus to form a single episodic memory.After looking at the consolidation theory – the example of H.M.’s lack of new long term episodic or semantic memory formation suggests that the process of consideration was unable to occur because of the lack of coordination between the structures needed to make new memories.
74 ORThink …..The hippo on campus lives on memory lane
75 Deep within the temporal lobe- the amygdala Mediation of fear – sympathetic arousalSeizures involving the amygdala involve intense fearDamage leaves a person unable to learn a fear response through classical conditioningInvolved in remembering the emotional significance of an eventCan effect the consolidation of memory – stimulation better recall, retardation poorer recallAlso concerned with learning.
76 Read box 6.10 on p 341 brain trauma & memory loss – boxing Learning Activity 6. 29 Page 342 questions 1 – 6
77 Amnesia Amnesia refers to any form of memory loss Can be partial or completeCan be temporary or permanentAmnesia is usually caused by brain trauma (inflicted brain injury or acquired brain injury)The severity of the injury determines the type and severity of the amnesiaUsually experience a period of unconsciousness, followed by a period of confusion, then the period of time ‘forgotten’ usually shrinks to only a few seconds of minutes directly after the moment of traumaExperience of amnesia can vary from a few days to several weeks, but commonly disappears suddenly, often after a natural sleep.
78 Types of Amnesia Anterograde amnesia Loss of memory of experiences that occur after the brain traumaDifficulty learning new informationCan clearly recall events before the traumaCan retain new info in STM indefinitely as long as it is rehearsedProblem lies in the transference of information from STM into LTMExperienced by people with Korsakoff’s syndrome and Alzheimer's diseaseKorsakaff’s syndrome (neurodegenerative disease)Acute inflammation and damage to hippocampus and thalamusOften associated with chronic alcoholism and thiamine deficiency
79 Types of Amnesia Retrograde amnesia R Loss of memory of old info and experiences before the trauma occurredLoss can extend back from moments to yearsUsually temporaryHowever, very common to permanently ‘lose’ the memory of the moment leading up to the trauma itselfThis permanent loss is explained by the interruption of consolidation into LTM
80 Learning Activity p 347 Questions 1-6 then … Movie analysis: Memento/50 First Dates vs. The Bourne IdentityComment on how accurately the movie portrays the amnesia, include a psychological description and explanation of the amnesia and the accuracy of these symptoms as depicted in the movie.1 paragraph ONLY.
81 Dementia & Alzheimer’s Disease Dementia & Alzheimer's discussed in this study design (for a full list FYI you can read box 6.12 for common types of dementia)Common acquired brain injury is caused by neurodegenerative disease where brain tissue slowly deteriorates over timeDementiaProgressive decline in mental functioningLoss of mental capacity: decline in intellectual ability, poor judgment, poor social skills and abnormal emotional reactionsMemory loss is persistent and progressiveNot a normal part of ageingComes in many different forms
82 Alzheimer’s Disease Alzheimer’s disease A form of dementia Physical break down of neurons causes plaques in the brain – sections of neurons tightly bound together, causing gaps in other areas (only observable post-mortem) caused by high concentration of the protein amyloid in the brain (see next slide for Amy Loid!)Often have low concentrations of neurotransmitter; acetylcholineAffects around people in AustraliaNo accurate diagnostic tests available. Only accurately diagnosed after death and brain tissue is examined for plaquesMemory loss, confusion, irritability and impaired decision-making are common symptomsMemory loss is persistent and progressiveEpisodic memories are affectedForget words and names of people and commonly known factsLose ability to follow directions of a story plotLose ability to perform everyday skillsNo cure, but can treat early stages with acetylcholine.Alzheimer’s Disease
83 Alzheimer’s Disease: Post-mortem So we know:Show high levels of the protein AmyloidNot usually in the brainHighly toxic – causes cell deathCauses the development of the plaques and tanglesBrains also have a massive lack of acetylcholine (an important neurotransmitter)The rhyme:
85 Memory decline over the lifespan Memory decline is not an inevitable consequence of ageingIf it does decline, short-term memory and explicit declarative memories (episodic and semantic) tend to be affected, rather than procedural memoriesAging and STM declineInfo transmission in NS is generally less efficient in older people (physical effects of ageing)The more complicated the task, the more STM decline is evident in older peopleLess activity in areas of the frontal lobe associated with STM when >60 years old
86 Memory decline over the lifespan Ageing and LTM declineEpisodic memories have been shown to start a steady decline as early as 30 years oldProcedural memories appear to remain intact over timeSemantic memories don’t appear to be affected much by ageHowever, older people don’t tend to encode new information in as much detail or as accurately as younger people – so often takes an older person longer to learn new thingsSpeed and fluency of retrieval also tends to decline with ageDecline in memory in older people is often explained by lack of motivation or more commonly, a lack of confidenceRecall of items is lower, but recognition of items is no different than younger people – use recognition tests, not recallMemory decline can also be explain by cognitive slowing due to natural shrinkage of frontal lobes with age. Cognitive slowing affects all cognitive processes, not just memory
87 So to recap ….. Older people Do take longer to learn new info STM – depends on the task, easy one part tasks ok, tasks that require divided attention not so good. Recall down, Recognition same.LTM - Episodic down, Procedural same, Semantic Same.