The Dummies Guide to the Cognitive approach

Summary

Definition and key terms

STM, LTM, information processing, encoding, storage, retrieval, capacity and duration, schemas

Methodology Laboratory experiments, Field experiements, natural experiments.Type 1 & type 2 errors. Wilcoxon and ManWhitney U tests. Case study (HM)

Content Working memory (Baddeley & Hitch), multistore memory (Atkinson & Schiffrin), episodic and semantic memory (Tulving), reconstructive theory of memory (Bartlett)

Two studies in detail Baddeley (1966b) and Sebastián & Hernández-Gil (2012)Key Question How can Psychologists’ understanding of memory help patients with dementia?Practical Experiment on memory to gather quantiative data, (Mann Whitney)

Key assumptionsCognitive psychology is about what happens to information as it is received through our senses and how it is processed. Cognitivists study mental processes, such as perception, memory, attention, language and problem solving, in order to understand how we view, interpret and respond to our world. Cognitive psychologists investigate mental processes by examining people with cognitive impairments. By doing this, they are able to understand how damage affects processing ability. They also use experimentation and brain imaging to gather information about the nature and location of cognitive modules.

1) The computer analogy:We process (perceive, remember, speak and forget) info just as computers do, and there is input-(keyboard) processing (CPU) –output (screen/printer). There are similarities between the two but humans use bodylanguage and emotions which makes output much more complex.2) The information processing approach:Thinking, perceiving and using language and memorizing are all ways of processing info. We receive (input) info through our senses. Interpret (encode) it and respond in some way (output). An example is the Multi-store model of memory.

Memory is defined as taking in information, putting it somewhere for use later on. It has 3 stages, encoding (laying down a memory trace), storage (putting it somewhere and keeping it there) and retrieval (recall). A memory trace is called an engram

MULTI STORE MODEL. Atkinson & Shiffrin (1968) Information processing model, information flows through a series of storage systems; Sensory register (SR), STM and LTM. Each stage differs in terms of; Coding, Capacity, Duration.

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Coding Capacity DurationSensory register (SR) Modality specific, sight,

sound, touch, taste, smellLarge for each modality, eg iconic store can hold 15-20 images (Sperling 1960)

Depends on the modality and age. Eg iconic store averages 500ms, echoic store has 2 seconds

Short Term memory (STM)

Can be coded in many ways but mainly acoustic (Baddeley 1966)

7 + 2 (Digit span test)chunking can help increase storage (Miller)

18-20 seconds (Peterson & Peterson)

Long term memory (LTM)

Verbal material is mainly coded semantically but also Visual or acoustic. Involves different brain areas which suggests they are encoded in different ways

Potentially Unlimited unlimited

STRENGTH: The first cognitive explanation of memory. STRENGTH : there is considerable research evidence for the existence of separate memory stores (Baddeley, Miller, Peterson & Peterson) Primacy recency effect (glanzer & cunitz)STRENGTH: support from amnesia cases where patients have lost their LTM or STM abilitites. EG. Clive Wearing case study shows damage to hippocampus prevents LTM formationWEAKNESS: Too linear and oversimplified, WEAKNESS: Tests are artificial (Digitspan test) and studies of brain damage (HM ) suggest memory is very complex. HM had brain surgery which left him unable to recall things that had just happened. It was concluded that he coudlnt move memories into LTM.WEAKNESS: cannot explain why some things are easier to recall or HOW information is processed.

STUDY - Peterson & Peterson (1959)Duration of STM Evaluation: Brown-Peterson technique supports theory, but displacement also explains forgetting in STM. Evidence supports but study is artificial.

Had participants recall nonsense trigrams after varying intervals (3,6 9 sec etc) During rehearsal an Interference task was given (counting backwards in threes) to prevent

rehearsal They found less that 10% of information was recalled after 18 seconds This is evidence for trace decay in STM. Participants weren’t able to practice/repeat the

information/memory, and so the memory traces decayedHowever, this was a laboratory experiment, so the study involved artificial tasks and an unnatural setting, and therefore lacked ecological validity. So the results may not be valid for the “real world”, and therefore this study cannot support the trace decay theory of forgetting

WORKING MEMORY - BADDELEY & HITCH (74)

Suggests that STM is not unitary but more complex and comprises of 3 main stores. The central executive is responsible for giving attention to

information from the other two stores and making decisions about which information is the most important. Rehearsal occurs between the central executive and the other stores.

The phonological loop is known as the “inner voice” and holds information in a speech based form; it has a limited capacity.

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The visuo-spatial scratchpad is known as the “inner eye” and is specialised for spatial and visual coding.

The Episodic buffer was added in 2000 as a 3rd slave system to explain how it is possible to temporarily store information combined together from CE,PL,VSS

Strength- much more detailed information about the processes involved inshort term memory making it superior to the multi-store model in this respect.Strength- highlights that memory is an active process rather than being passive.Strength- it has a practical application to the real world- dyslexia can affect either the phonological loop or the visuo-spatial scratchpad and therefore strategies can be put into place to help with reading and writing.Weakness- it only looks at short term memory- there is no explanation about how information is transferred between short and long term memory.Weakness- it has highlighted the role of sensory memory but ignored most of the senses- e.g- touch, smell, tasteWeakness- very little is known about the decision making activities of the central executive.

TYPES OF LONG TERM MEMORY – TULVING (72)

Suggests that LTM is too simple, there are a great many categories to memory.

Episodic – autobiographical record of personal experiences. (Birthdays, holidays etc). the strengths of the memory is influenced by emotion.

Semantic – contains all knowledge, facts meanings. Semantic and episodic memory overlap in LTM. Semantic memories are easier to recall due to the amount of links of several interrelated memories (not a single memory) associated in different brain areas.

Procedural – implicit (doesn’t require conscious thought) memory of knowing how to do something (speaking, walking, dressing).

Strength – neurophysicological evidence of brain damange (accident or disease) to those areas where episodic memories are effected has shown two memory systems present. (HM could not lay down new semantic or episodic memories)Weakness - because both LTM stores work together it is difficult to conduct reasearch because they cannot be studied in absolute isolation.

RECONSTRUCTIVE MEMORY – BARTLETT (32)

Memory is not a complete recording of what really happens in life. We use our past experiences when laying down memories. There are schemas (packets of information) that we have already learned or assumed to help us know what to do in particular situations or events. Remembering is not a playback or a recording it is using what we have seen or heard and relating the story through what we already know. This means that memory is a reconstructed process of shaping, interpreting and making sense of what we expect to see.

Study to support: To illustrate his theory he carried out a study called ‘War of the Ghosts’. It was an independent groups design; One group was given a serial reproductive task (repeating the story to each person in the group) and One group was given a repeated reproduction task, recalling the story 15 mins later and then 20hrs, 8 days, 6 moths, 10yrs later.

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Bartlett found that the participants retellings of the story differed from the original in several ways; Form (westernised order), Additions (changes), Detail and Simplification (it became shortened). The story didn’t make sense to ppts because it was of a different culture, so they didn’t have all the schemas for the events in the story. Ppts changed the story so that it made sense to them. (rationalization) and picked out central features of the story and missed out other bits.(stuff that didn’t make sense). When asked to recall later the story became shorter. Bartlett showed that people reconstructed the story (confabulation) to fit their schema.

Strengths : there is much evidence for the theory (Brandsford & Johnson, including work of Loftus on EWT. Strength: The theory can be tested experimentally because the IV can be operationalised and measured to establish cause and effect.Weakness: Bartlett’s story did not make sense so the ppts could have altered it because of demand characteristics. Weakness : The theory describes memory as reconstructive but does not explain how it is processed or how schemas are aquired in the first place.

BADDELEY 1966 – encoding in STM and LTM

AIM: to assess whether coding in STM and LTM is mainly acousitc (sound) or semantic (meaning).

Expt 1:List A: 10 words acousitcally similar (man, cab, can, cad)List B: 10 words acousitcally disimlar (pit, few, pen sup)List C: 10 adjectives with smilar meaning (great, large, big, huge)ListD: 10 adjectives matching ( good, huge, hot, safe)

Indpendent groups design. (4 groups) Words presented in 3sec intervals 40 sec recall in the right order 20 min task Retest to write down as many words in order from initial test

Results:The order of the words was not so well recalled in the acoustically similar list but there was not so much forgetting either.In the semantically similar list, the recall was not different from that in the control list. It was the acoustic similarity that caused difficulties.

Expt 2:List A: 10 words acousitcally similar (man, cab, can, cadList C: 10 adjectives with smilar meaning (great, large, big, huge)

Conditon X – learning same as in Expt 1. 2x groups (List A or List C) with immediate recall. 20min gap then recall

Condition Y – same as Expt 1 but a task between each presentation of the list. 2x groups (List A and List C with interference task between learning and recall. 20 min gap then recall

Condition Z- same as conditon Y but interference task between test and next presentation (control). 2x groups (List A and List C) with immediate recall for first recall and then interference task in next trail. 20 minute gap and then recall

Where there was interference to stop recall in STM there was a significant effect in learning. Therefore he realised he needed to use interference to block the STM and test LTM properly.Interference task: 8 numbers presented in 1 sec intervals recalled in order they appear

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Expt 3:Visual presentation was used to prevent mishearing. Words presented visulaly by slide projector

PROCEDURE: 75 ppts were presented with one of 4 word lists, repeated 4 times using condition Y in expt 2.-interference task between learning and recallLIST A –10 acousitcally similar words (cat, mat, sat)LIST B – 10 acoustically dismilar words (pit, day, cow)LIST C– 10 semanticaly similar words (big, huge, tall)LIST D – 10 semantically disimilar words (hot, safe, foul)

To test coding in STM: ppts were given a list containing the original words in the wrong order and their task was to rearrange in the correct orderTo test procedure for LTM: same as above but with 20 min interval before recall doing an interference task.Each word was presented with 3sec intervals.After 4 learning trials they were given a 15 min interference task followed by a retest of the word list sequence

FINDINGS: When interference used, recall in acoustically similar condition and control condition was similar. In LTM acoustic similarlity did not affect recall. In semantic similarity recall was much better in the control compared to recall in LTM.

For STM, ppts that were given LIST A performed the worst (10% recall). Recall for other lists were good (60-80% recall)

For LTM: ppts with LIST C performed the worst (55%). Recall for other lists were comparatively good (70-85%)

CONCLUSIONS: • LIST A was recalled the least efficiently in STM suggesting STM is coded on an acoustic basis. They

confused similar sounding words.• LIST C was recalled the least efficiently for LTM suggesting LTM is coded on a semantic basis. They

confused similar meaning wordsCRITICISMS:Strength: It was a lab study therefore is able to establish cause and effect between the IV (semantic or acoustic word) and the DV (LTM) and can also be replicated to check the resultsStrength: The small difference in recall between semantically similar (64%) and semantically dissiilar(71%) suggests there is also semantic coding in STMWeakness: Difficult to generalise to everyday findings because the task were contrived and mundane laboratory tests reducing validity of the way we use memory.(we do not learn random monosyllabic words on an everyday basis)Weakness: The study does not reflect the complexities of memory, there are other ways in which LTM can be categoriesed such as episodic, procedural and declarative memory.

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Sebastián & Hernández-Gil (2012) Developmental pattern of digit span in Spanish population

AIM: To investigate the development of the phonological loop in children aged 5-17 using digit span as a measure of phonological capacity. Compare findings to previous research of adult, aged and dementia patients.

PROCEDURE:

Who? 570 volunteers from Madrid schools. Aged 5-17.Selected by school year.Controlled for education and cognitive levels: no Ps had repeated a year. No hearing/reading/writing difficulties.

What? Independent measures. Digit span test.Random sequence of digits read aloud by experimenters at 1 digit per second. Gradually increased in length.

When? 2012. Task done in Ps breaks individually.

Where? P’s school.

How? • 3 sequences of 3 digits.• Ps asked to recall in same order. Given e.g. to check they understood.

Gradually increased.• Digit span is maximum length at which Ps could recall at least two of the

three series with no errors.• Results analysed by school year and by developmental period (5y; 6-8y; 9-

11y; 12-14y; 15-17y)

FINDINGS:Digit span increases with age from 3.76 at 5 years to 5.91 at 17 yearsCompared to data from 2010 study: healthy older people had a higher didgit span than 5 and 6 year olds. Those with Alzheimers and dementia had a similar digit span to the youngest group.

CONCLUSIONS:Digit span increases from 5 to 17 years.Spanish digit span 1 digit below that of English speakers: due to word length of spanish numbers. This links to subvocal rehearsal that fits Baddeley’s WMM. Older healthy peoplehave alower digit span suggesting decline over time.Demetia does not have a big impact on digit span.

CRITICISMS:Generalisability: Large sample size aids generalisability, although participants with hearing, reading or language impairments were excluded.Reliability: controls; Ps had similar hearing/reading/writing levels. Digit span tested in same way for each PValidity: Lacks ecological validity: does digit span reflect everyday verbal memory?

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CASE STUDIES OF BRAIN DAMAGED PATIENTS

Case studies gather both qualitative and quantiative data. They are in depth and detailed focusing on often one person or a group of ppt. They are critical for cognitive psychologists to investigate how brain injury affects cognitive functioning. However case studies are rare and therefore small in number which limits generalisabiity

HM – Henry Molaison had his hippocampus removed bilaterally in 1953 to treat severe epilepsy. He died in 2008. The surgery successfully cured his epilepsy, but left him with severe anterograde amnesia. He could no longer form new episodic memories, but his ability for procedural learning remained intact. Rare occasions: HM recalls post-op episodic events, e.g. picture recognition task showed HM recalls magazine picture 6 months later. Also able to recognise a few famous people post-op who were not famous pre-op. e.g. George Bush. He spent hours looking at pictures of these people. Able to draw floor plan of his house (moved into post-op) suggests spatial memory linked to brain areas outside medial temporal lobe.(Schmolck et al 2002) found that the lateral temporal cortex was important for semantic knowledge the more damage the more impairement.Phineas Gage – had damage to prefrontal lobe following an accident. His behaviour become more unrestrained after the accident suggesting the role of frontal lobe for problem solving and decision making.

Strength: where there are more than one case study showing the same brain damage with same cognitive difficulties gives reliabiity to findings in brain structures responsible.Strength: measurements from brain scanning are reliable as can be checked by other peopleWeakness: it is difficult to identify one particular strucure for memory and processing due to the different brain regions.Weakness: brain damage rarely occurs in one specific area, surrounding areas are also affected so difficult to isolate where processing may take placeWeakness: neuroimaging only good for large areas of damage

KEY QUESTION

How can Psychologist’s understanding of memory help patients with dementia?

Dementia is a label for a cluster of symptoms involving deterioration of cognitive function with resulting changes in behaviours that interfere with the ability of an individual to function independently in everyday life.It is not a disease but a condition that results from any of several neurological diseases, eg Alzheimer’s disease affects areas of the brain that prevents the ability to learn new information, use language or perceive objects/people. It is a key question for society because diagnosis for people having dementia is increasing. Dementia costs £23 billion a year and mostly need full time care.

Understanding of STM and LTM can help understand how it affects someone with dementia. For example, they forget what they have been told because the memory was not encoded therefore not stored. Therefore it is important to be very specific when talking or asking questions so instead of saying ‘have you had a visitor today?’ psychologists suggest ‘has your daughter, Jean, been to visit you?’. Also using pictures, photos, colours can help with memories. Practical ideas for coping on a daily basis would be to write down what colour their food tray is for lunch, labeling keys and doors etc.

WMM suggests that different tasks are done at the same time, (Baddeley) which is difficult for someone with dementia. For example trying to attend to what someone is saying would be better if there is no background noise with one person talking at a time.

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Understanding Bartlett’s reconstructive theory of memory is also useful, if memories are reconstructed using schemas then someone with dementia who seems to be saying something but it is all mixed up might be using mixed schemas and muddled episodic memories, so it is advised to listen carefully, ask limited questions but follow the thought processes.

Psychologists have much to offer in assessing spared and impaired cognitive dysfunctions, not only in tackling the various disease processes through clinical research, but also in designing intervention programs that minimize the effects of cognitive disabilities. Although there are a number of medications that can slow progression of the disease they do not stop or prevent the onset and the risks and side-effects must be taken into consideration.

Psychological interventions involves an initial assessment of the symptoms – what they are and what makes them better or worse. Warning signs that would warrant further investigation include;

Difficulty remembering names or people Needing things to be repeated and reminders for appointments Forgetting to take medication, recent events, paying bills etc Misplacing losing personal items Getting lost in familiar surroundings

The psychologist then uses the findings from the assessment to develop a plan for intervention. For example, interventions such as sensory stimulation include giving the patient fabric or a foam ball to handle, pictures in a book or magazine to look at, music to listen to, scents to smell, etc. This is because they need to draw on prior knowledge of what they are trying to recall , by displaying or explaining prior knowledge it might help someone with dementia. (Steyvers and Hemmer 2012).

Some of the ways a psychologist can help include: Providing education to help understand the cognitive impairments and how they relate to changes in

the individuals’ behaviour and the impact of cognitive impairments on everyday activities; Providing training to individuals to help them compensate for their cognitive impairments; Teaching family members, friends, or care providers, means of helping the individual; Providing the family members, friends, or care providers with coping skills to deal with cognitive and

challenging behaviours; Providing access to good educational information and community support services.

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