January 9, 2018 | Author: Anonymous | Category: Social Science, Psychology, Cognitive Psychology
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Chapter 6: Memory

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 chunking  Alan Baddeley and Graham Hitch’s model of working memory: central executive, phonological loop, visuo-spatial sketchpad, episodic buffer  levels of processing as informed by Fergus Craik and Robert Lockhart  organisation of long-term memory including declarative and episodic memory, and semantic network theory Neural basis of memory:  role of the neuron in memory formation informed by the work of E. Richard Kandel  roles of the hippocampus and temporal lobe  consolidation theory  memory decline over the lifespan  amnesia resulting from brain trauma and neurodegenerative diseases including dementia and Alzheimer’s disease

 S/N

Work Requirements

Glossary – due 15th May, 2012 Workbook 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, 2012 or earlier  90% attendance rate Note  

 SACs

ERA  Week 3 (approx.)  /30 marks  Test  Week 8 (approx.)  /20 marks 

If 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 email do not satisfy this requirement, and if a medical certificate is not produced, a score of 0 will be given

 -


 -


Defining memory Models for explaining human memory The Atkinson-Shiffrin multi store model Sensory memory Short term memory Craik & Lockharts levels of processing framework Braddeley & Hitch’s model of working memory Long Term memory Serial position effect Neural basis of memory Role of the neuron in memory formation Role of hippocampus & temporal lobe consolidation theory Amnesia resulting from brain trauma & neurodegenerative diseases Memory decline over the lifespan

How is information processed?

Memory is not a ‘single organ’ or a single ‘thing’, rather it consists of a collection of complex interconnected and interacting systems  We do not have a memory, but we have different memory systems which share a common function of: 

Processing different information

storing information (learned through experience) Memory systems retrieving the information (when needed)

Storing information (in different ways & types of information)

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!

Memory 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 form  Storage – retaining information in memory  Retrieval – information recovered from memory when needed  All three processes are required and if any one is not included, the memory will not form. (see fig 6.4 on page 291) 

Memory is an active (uses energy) information-processing system that:  Receives,  Organises  Stores &recovers information

Encoding Incoming sensory input

• Info is converted for storage

• Info is retained in brain


Retrieval • Info is recovered when needed

Memory actively alters and organises information, then stores it so that it can be easily retrieved when needed

There are 3 key processes involved in these systems. If any of these processes fail, memory will fail

An additional aspect of the Atkinson & Shiffrin human multi store model included: 

Structural features & Control processes.

 Encoding

= hitting the letters on the key board -> it goes into the computer

 Storage

= we hit ‘save’ -> we name the file and store the information for later on when we save the file

 Retrieval

= 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!

Automatic & effortful encoding Encoding can be spilt further into categories. read, define & provide and example of automatic encoding & effortful encoding

Page 292 of your text, Questions 1,2 & 3

 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 MODEL  The

three main theories that explain how human memory functions are: 1. Atkinson-Shiffrin multi-store model 2. Baddeley and Hitch’s model of working memory 3. Craik and Lockhart’s levels of processing framework

 

  

Based in the 1960’s Proposed 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

Sensory register •

If information is attended to, it moves into short term memory store

The entry point for all new information into memory from the external environment Stores vast amount of incoming visual information, for 100’s milliseconds

Short term store • •

If information is not attended to, it is lost

• •

A temporary working memory Here we can manipulate information from every day/common tasks Holds all information that we are aware of at that point in time Has a limited capacity – 7 items at 1 time Only held for about 30 sec unless we make an effort to keep it there (attend to it), eg rehearsal

Long term store • • •

• •

Information held relatively permanently in an highly organised way Essentially can be an unlimited capacity Unlike sensory register & short term store – information in long term store does not usually decay and can stored for …… a whole lifetime According to Atkinson & Shiffrin – it is our inability to retrieve required information that results ineffective search strategies Problems with retrieval may also be due to ‘interference’ with the information and this results in a disruption in the retrieval process

Rehearsal Paid attention to info

Sensory info

Sensory Memory

Info encoded or rehearsed

Short-term Memory

Long-term Memory Retrieval

Info not paid attention to…

Not rehearsed or encoded

Lost from sensory memory

Displaced from short-term memory

Various reasons

Forgotten CRIMD

 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 it  Rehearsal – process that goes over information and helps it be stored 

But all of this was developed over 40 years ago ….. And we know have more knowledge …

Advantages 

Identified characteristics of short term store as being different and apart from long term memory Recognised the importance of short term store & its fundamental roles Manitence and rehearsal are still relevant, although now more complex Despite some newly learnt differences, still held as the original multi store model, although now just more complex

Limitations 

It is now clear that information does not ‘just flow’ as described in Atkinson & Shiffrin’ 3 stage sequence

There is a separate sensory register for auditory information & haptic (touch) information – and maybe even more now referred to as a sensory memory system

Short term store now believed to be a much more complex system

Different types of rehearsal have been identified in short term memory

Long term store is no longer a single store -> rather it includes more complex systems & structures of storage.

Page 295 of your text, Questions 1-7

Sensory Memory    

Entry point of memory Capacity 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 memory Incoming stimuli is stored as a memory trace in different sensory registers based on the type of sense  

Iconic memory – visual Echoic memory - auditory

 Iconic

memory ( I as in eye)

Visual images are stored here for about 0.2-0.4 seconds  Stored as overlapping images  Allows perception of flowing movement during a film, or a figure drawn with a sparkler at night 

 Echoic

memory (e as in ear)

Sound stimuli are stored here for around 3-4 seconds  This is longer than in iconic memory as sound takes longer to produce  Allows comprehension of speech by connecting individual sounds coherently into words and sentences 

Page 299 of your text, Questions 1-7

 Activity: 

Read aloud the following series of numbers and ask students to recall each line in order.        

Capacity of STM

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 STM

Students learn the following sequence of numbers 4, 5, 3, 6, 2, 7, 8 Test immediately, then after 2 minutes  How many people remembered the sequence? This is duration of STM   

 Short-term

memory (STM) is a memory system that has a limited capacity and duration  It also stores the information in an encoded format  Described as the “seat of conscious thought” – information only registers in STM once it is paid attention to – in conscious awareness  Duration of STM 

Without 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

Page 307 of your text, Questions 1-7, don’t worry about Q 8.

 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 below

Now becomes ..

 

Recalling information from long-term memory can also displace items from STM Information is lost primarily within STM by either displacement (pushing out) or by decay (not being used- think fruit!)

Capacity of STM cont…..  Chunking

is a method of increasing the capacity of

STM      

Definiton: 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 chunks Chunks can be numbers, images, words, sentences, phrases and even abbreviations This is why we have phone numbers broken into parts …… 5427 2600 rather than 54272600.

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 ways  Enables us to use the information in sensory memory and move it to LTM  Often 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

 Rehearsal

is the process of actively and consciously manipulating information to keep it in STM for longer than the normal 18 sec. (Increases duration)  Maintenance rehearsal   

Repeating info over and over usually vocally (out loud) or subvocally (in your head) Works indefinitely to keep info in STM Does not always transfer info into long-term memory

 Elaborate   


Links new info to existing knowledge in a meaningful way More active than maintenance rehearsal (requires more effort) Very effective in transferring info into long-term memory, especially when using personal link (self-reference effect)

Maintenance Rehearsal Elaborative Paid attention to info Rehearsal Sensory info

Sensory Memory

Short-term Memory

Long-term Memory Retrieval

Info not paid attention to…

Not rehearsed or encoded

Lost from sensory memory

Displaced from short-term memory

Various reasons

Forgotten CRIMD

Page 312 – we can do this one as a class!

 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 retrieved Due to the sheer volume of info in LTM, we use cues (intentional or unintentional) to speed up the process of retrieval Cues enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fast Once retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTM Failure to retrieve info from LTM is usually due to poor organisation during encoding and storage, or an inappropriate cue was used during retrieval Info is encoded in terms of its meaning (semantically)

 Memories

in LTM are relatively permanent or at least very longlasting  Forgetting is most likely due to a failure to retrieve info – poor encoding or poor cue  Retrieval 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?”)

①     

Knowing how to do stuff – actions and activities Often difficult to explain this knowledge Usually learnt through observation and practice Not usually consciously recalled E.g. making a cup of tea/riding a bike

Declarative memory (Explicit memories – “What?”)

Memories of facts and/or events  Usually consciously recalled  Two types of declarative memory: a) Episodic memory 

 

Memories of specific events or personal experiences Include references to “when” and “where”

Semantic memory

b)   

Memories of general academic knowledge Facts not necessarily related to a specific place or time Include references about “what” and “who”

Stage of memory Sensory memory (SM)


•Receives sensory Original sensory form information (stimuli) E.g. lingering sense of from environment sound or pressure

Short-term •Receives info from memory SM (STM) •Receives info from LTM

Long-term memory (LTM)

Form of storage

•Storehouse for encoded info coming from STM




•Varies based on sensation •Usually between 0.2 – 4 sec •Occasionally up to 10 sec

Encoded in terms of physical properties of stimuli E.g. Starts with L

7 ±2 pieces •Usually 18-20 or chunks sec of info •Occasionally up to 30 sec

Encoded in terms of semantics - meaning


•Potentially permanent

 Craik

and Lockhart proposed a framework of memory that emphasised the importance of the level of processing in how well information is stored in LTM  Info 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 rehearsal  The deeper the level of processing (more elaborate encoding) the better the recall   

Visual encoding – “is there a letter k in the word?” Acoustic encoding – “does it rhyme with hat?” Semantic encoding – “is it a synonym of difficult?”

 Levels of processing or depth are hard to define specifically and to measure  Despite this problem the idea of better processing and therefore better storage is supported widely by research

Craik and Lockhart Shallow processing

Visual encoding

What the word looks like

Colours, shapes and patterns detected

Intermediate processing

Acoustic encoding

What the word sounds like

Item is identified

Deep processing

Semantic encoding

What the word means

Meaningful associations are made

 Baddeley

and Hitch’s model of working memory describes STM as a functional system with three components that work independently but can also interact: ① 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)

②  

Visual info is anything you can see or imagine, spatial info is position and location of objects in space Also has limited duration and capacity (around 4 items)

Central executive

Controls attention  Integrates information from the phonological loop and visuo-spatial sketchpad with info from LTM  Coordinates the flow of info between the working memory system and LTM  Manipulates the info held in the phonological loops and visuo-spatial sketchpad – the working component of the model of working memory 

Episodic buffer (a fourth component added in 2000)   

A sub-system of the working memory that enables the different components to interact with LTM Has 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 way Controlled by central executive

Sensory input Rehearsal

Rehearsal Phonological loop

Visuo-spatial sketchpad

Central Executive Episodic Buffer Long-Term Memory

Phonological Loop

Central Executive • Controls attention • Integrates info from the two storage sub systems • does the ‘working out’

storage of verbal speech information

Episodic Buffer Integrates useful LTM into what currently being worked on Pulls together streams of different info into ‘episodes’ as a meaningful whole

•The seat of consciousness

Visio spatial Sketchpad Storage of visual and spatial information

The workbench

 Read

example on pg. 319

 Once

we have read it .....Going to party the following



is: phonological loop stores the directions Visio spatial sketchpad visualises the route Central executive directs the Episodic buffer to combine information from storage branches Episodic buffer also adds information from LTM Episodic buffer used as the mental ‘workbench’ to make adjustments

Page 314 questions 1-6 & page 320 questions 1, 4, 5, 7 ONLY

 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 retrieved Due to the sheer volume of info in LTM, we use cues (intentional or unintentional) to speed up the process of retrieval Cues ( retrieval cues) enable retrieval of specific info, not the entire contents of LTM – usually very efficient and very fast Once retrieved, the info is stored in STM until it is no longer needed/in use. It is then transferred back into LTM Failure to retrieve info from LTM is usually due to poor Organisation during encoding and storage, or an inappropriate cue was used during retrieval Info is encoded in terms of its meaning (semantically)

 Memories

in LTM are relatively permanent or at least very longlasting  Forgetting is most likely due to a failure to retrieve info – poor encoding or poor cue  There are two major types of LTM (LTM stores): ① Procedural memory (Implicit memories – “how?”)     

Knowing how to do stuff – actions and activities Often difficult to explain this knowledge Usually learnt through observation and practice Not usually consciously recalled E.g. making a cup of tea/riding a bike

Declarative memory (Explicit memories – “What?”)

Memories of facts and/or events  Usually consciously recalled  Two types of declarative memory: a) Episodic memory 

 

Memories of specific events or personal experiences Include references to “when” and “where”

Semantic memory

b)   

Memories of general academic knowledge Facts not necessarily related to a specific place or time Include references about “what” and “who”

 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.

 Complete

the table in your workbooks

Types of Long Term Memories Procedural Memories Definition:

Example: Declarative Memories

Definition: Episodic Memory Example:

Example: Semantic Memory Example:

Page 325 questions 1-5 &

Long term memory’s most distinctive feature is its organisation of information  The 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 7 + 2 items to locate the relevant information.  This 7 + 2 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. 

Research into LTM has been studied for over 65 years now. Research suggests: Bousfeild & Sedgewick, 1944  Information 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 LTM Bousfeild, 1953  Noticed that when asked to recall information, people would recall the words in groups or clusters, without being aware Hockenbury & Hockenbury, 2006  It is still believed today that there is some kind of logical association in LTM Bower & Clark, 1969  Found that words that were memorised in stories would recall up to 90% of 12 words compared to only 15% of words remembered in any order  They concluded that the results from recall in LTM were improved using some organisation method. 

Page 327 questions 1 – 10 These are great exam practice questions !

 Information

is stored in LTM as series of overlapping

networks  Each network is interconnected by meaningful links  Each item of information or concept in the network is called a node  When a node in a network is activated (retrieved) all other related nodes are made available (easier to retrieve) – spreading activation  Linking multiple concepts removes the need for multiple copies of the same information  The shorter or thicker the link between nodes, the stronger the association between them and the faster the retrieval  Think of the semantic network theory as towns as nodes and the highways & streets as links


Traffic lights

Fire Engine




Red Emergency

Yellow Blue



Courage Apple

Page 330 questions 1 – 2 ONLY These are great exam practice questions !

 

The serial position effect describes the differences in ability to recall items in a list depending on their position in that list For 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 recalled Recency effect  Superior recall of items at the end of the list (most recently experienced)  Still in STM so easy to retrieve Primacy effect  Superior recall of items at the start of the list  Had the most time to rehearse for probably retrieved from LTM Items 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 recalled Most clearly shown when tested immediately after exposure to the list. After 30 seconds recency effect is less apparent


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.

Page 333 questions 1 – 3

Memories are stored throughout the brain linked together by memory traces or “circuits” – interconnected neurons

However, different parts of the brain are involved in memory formation and retrieval to different degrees, and in different types of memories

New memories (either short or long term) are NOT stored in individual synapses but in the pattern of thousands of new interrelated connections

Looking for memories in a single nerve cell or synapse is a dead end

We 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.

 Read

pages 335 – 336

 Kandel

identified that there are physical changes to neurons during the formation of new memories    

Worked primarily with large sea slugs (Aplysia californica) Has very simple Nervous System 20, 000 neurons Largest observable neurons – can be seen with the naked eye!

 

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 quickly  Forgetting – an hour later the withdrawal was again slow, progressively faster with continued stimulation  Habituation – eventually the slug stopped responding to the stimulation as it caused no damage, it had ‘learned’ that the shock was harmless Retraction of the gills changes over time indicating memory, so Each day the slug would habituate more quickly than the day before This suggest some kind of LTM lasting days or even weeks

By studying the neurons involved in this process he identified the changes that allowed the learning to take place The neurons were physically changing!

These changes are called collectively Long Term Potentiation

 Neural

basis for memory formation  Synapse strength can increase in 3 ways -

Release extra neurotransmitter Increase number of receptor sites Growth of new synapses

New Receptor Formation

Stronger neural impulse in post synaptic neuron

 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 connections New synaptic junctions are formed between neurons – creating new memory traces /neural pathways

 Short-term

memory storage only tends to increase neurotransmitter production, while long-term storage produces functional and structural changes

 As

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

Page 337 questions 1 – 11

 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 lobe Corpus callosum Thalamus Amygdala

 

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 epilepsy Medical success in preventing seizures, however it affected his memory His 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 memories

Other mental abilities and STM fine  Eg. He could retain info in STM as long as he maintained attention and actively rehearsed it, but could not transfer it into LTM

 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 however  Evidence

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)

Information 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 consolidation  Reconsolidation is the process of returning information back to LTM after it has been retrieved and used – the memory may be altered in this time. 

The research

Rats learned to run a maze to find a food reward  4 groups A – ECT immediately B – ECT 20 seconds after C – ECT 30 minutes after D – ECT 60 minutes after 

The Results

A – all rats forgot completely B – partial recall C – partial recall (better than B) D – total recall 

Consolidation seems complete after about 1 hour

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.

 Mediation

of fear – sympathetic arousal  Seizures involving the amygdala involve intense fear  Damage leaves a person unable to learn a fear response through classical conditioning  Involved in remembering the emotional significance of an event  Can effect the consolidation of memory – stimulation better recall, retardation poorer recall  Also concerned with learning.

Page 342 questions 1 – 6

Amnesia refers to any form of memory loss  

Can be partial or complete Can be temporary or permanent

Amnesia 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 amnesia 

Usually 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 trauma

Experience of amnesia can vary from a few days to several weeks, but commonly disappears suddenly, often after a natural sleep.

①    

 

Anterograde amnesia Loss of memory of experiences that occur after the brain trauma Difficulty learning new information Can clearly recall events before the trauma Can retain new info in STM indefinitely as long as it is rehearsed Problem lies in the transference of information from STM into LTM Experienced by people with Korsakoff’s syndrome and Alzheimer's disease   

Korsakaff’s syndrome (neurodegenerative disease) Acute inflammation and damage to hippocampus and thalamus Often associated with chronic alcoholism and thiamine deficiency


Retrograde amnesia

②     

Loss of memory of old info and experiences before the trauma occurred Loss can extend back from moments to years Usually temporary However, very common to permanently ‘lose’ the memory of the moment leading up to the trauma itself This permanent loss is explained by the interruption of consolidation into LTM

Comment 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.

 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 time  Dementia  

 

Progressive decline in mental functioning Loss of mental capacity: decline in intellectual ability, poor judgment, poor social skills and abnormal emotional reactions Memory loss is persistent and progressive Not a normal part of ageing Comes in many different forms

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; acetylcholine Affects around 100 000 people in Australia No accurate diagnostic tests available. Only accurately diagnosed after death and brain tissue is examined for plaques Memory loss, confusion, irritability and impaired decision-making are common symptoms Memory loss is persistent and progressive    

Episodic memories are affected Forget words and names of people and commonly known facts Lose ability to follow directions of a story plot Lose ability to perform everyday skills

No cure, but can treat early stages with acetylcholine.

So we know:  Show high levels of the protein Amyloid  Not usually in the brain  Highly toxic – causes cell death  Causes the development of the plaques and tangles  Brains also have a massive lack of acetylcholine (an important neurotransmitter)  The


Page 351 questions 1 – 3

 Memory

decline is not an inevitable consequence of

ageing  If it does decline, short-term memory and explicit declarative memories (episodic and semantic) tend to be affected, rather than procedural memories  Aging   

and STM decline

Info 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 people Less activity in areas of the frontal lobe associated with STM when >60 years old

Ageing and LTM decline  Episodic memories have been shown to start a steady decline as early as 30 years old  Procedural memories appear to remain intact over time  Semantic memories don’t appear to be affected much by age  However, 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 things  Speed and fluency of retrieval also tends to decline with age  Decline in memory in older people is often explained by lack of motivation or more commonly, a lack of confidence  Recall of items is lower, but recognition of items is no different than younger people – use recognition tests, not recall  Memory 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

 Older

people Do take longer to learn new info


– depends on the task, easy one part tasks ok, tasks that require divided attention not so good. Recall down, Recognition same.


- Episodic down, Procedural same, Semantic Same.

Page 351 questions 1 – 3

True/False Quiz on page 355

Practice Test on page 356-360

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