Schizophrenia Flashcards
1
Q
Définition of scz
A
‘severe mental disorder where contact with reality and insight is impaired. This is a type psychosis
2
Q
Define psychosis
A
losing contact with reality ( schizophrenia, BPD…)
3
Q
Three most common factors of people with schizophrenia
A
- most commonly experienced by men
- Most common by people who live in cities and lower socioeconomic groups
- Usually homeless/hospitalised
4
Q
What are positive symptoms of scz
2 eg
A
experiences that are addition to atypical experiences.
Delusions
Hallucinations
5
Q
Delusions
A
positive symptom of schizophrenia
cognitive process/thoughts : that have no basis in reality. This can be believing you’re someone else, part of a conspiracy or delusions of ‘GRANDEUR’
6
Q
Three types of delusions
A
- Delusions of grandeur: thinking you are more important/able than you are.
- Delusions of persecution : that you think is someone out to get you/watching you
- Delusions of paranoia: negative things are going to happen, not necessarily from another person.
7
Q
Hallucinations
A
- Hallucinations: positive symptom of schizophrenia
these are sensory experiences (any sense) that have either no basis in reality or are distorted perceptions of things that there are.
8
Q
What is a negative symptoms
A
loss of a typical experience. So the rest of the population experience something and schizophrenia dont experience it: a ‘loss’
9
Q
Speech poverty
A
A negative symptom of schizophrenia.
This involves reduced frequency of speaking and a reduced quality of speech (fluency)
10
Q
Avolition
A
A negative symptom of schizophrenia
Aka: lack of motivation, to carry out tasks. Lowered energy/activity
11
Q
What does Cheniaux et al (2009) show
A
The differences shows
1. There is a lack of agreement about what schizophrenia is
2. Over diagnosing: people are wrongly labelled and medicated
3. Under Diagnosing: lack of treatement they need
12
Q
Cheniaux (2009)
A
2 psychologists diagnosed 100 patients independently with both DSM and ICD.
They found the inter rater reliability was really low.
First psychologist:
Diagnosed 26 people with DSM
Diagnosed 44 people with ICD.
Second psychologist:
Diagnosed 13 with DSM
Diagnosed 24 with ICD.
The differences shows
There is a lack of agreement about what schizophrenia is
Over diagnosing: people are wrongly labelled and medicated
Under Diagnosing: lack of treatement they need
13
Q
Osorio (contradicting to Cheniaux)
A
Once DSM was updated inter rater reliability was very high.
180 individuals.
Pairs of interviewers had inter rater reliability of 97% reliable
And also test - retest reliability (double checking) of 92% reliable
This means that now schizophrenia may be more understood. There may be a higher temporal validity (2009 vs 2019)
Pros/cons
1. Concurrent validity - the extent to which a psychological measure relates to a pre-existing measure.
The ICD and DSM have low concurrent validity because they are different in achieving same measure.
14
Q
4 Issues in classification of scz
A
- Co morbidity
- Symptom overlap
- Gender bias
- Cultural bias/ racial bias
15
Q
What is concurrent validity
A
the extent to which a psychological measure relates to a pre-existing measure.
The ICD and DSM have low concurrent validity because they are different in achieving same measure.
16
Q
What is symptom overlap
A
When two or more conditions share symptoms,
lowering the validity of diagnoses in the DSM
as they can be mistakenly diagnosed
17
Q
Co morbidity
A
The occurrence of two or more disorders/conditions.
Aka schizophrenia and personality disorders.
Two disorders are frequently diagnosed together, which lowers the validity of classifying the disorders separately. This may either be that they have the same causes
18
Q
What is required to diagnose with the
1. DSM
2. ICD
A
DSM 5 : only requires one positive symptom to be present for diagnosis
ICD 11: requires two negative symptoms to be present for diagnosis.
19
Q
Study for symptoms overlap
A
Ketter (2005) : misdiagnosis due to symptom overlap can lead to years of delay in correct treatement. Degeneration (the issue getting worse) can occur as well as high levels of suicide.
20
Q
Ketter
A
Ketter (2005): misdiagnosis due to symptom overlap can lead to years of delay in correct treatement. Degeneration (the issue getting worse) can occur as well as high levels of suicide.
21
Q
Study for co morbidity
A
Buckley (2009) - found that around half patients with schizophrenia also have a diagnosis of:
Depression 50%
Substance abuse 47%
PTSD 29%
This shows that scz occurs commonly alongside other illnesses and the validity of the classification is questioned.
22
Q
Buckley (2009)
A
Is a study for co morbidity
Buckley (2009) - found that around half patients with schizophrenia also have a diagnosis of:
Depression 50%
Substance abuse 47%
PTSD 29%
This shows that scz occurs commonly alongside other illnesses and the validity of the classification is questioned.
23
Q
Two problems with diagnosing scz in terms of reliability
A
Co morbidity
Symptom overlap
24
Q
Two problems with diagnosing scz in terms of validity
A
Gender bias
Culture bias
25
Study for validity of gender bias (4)
Broverman (1970) :
Found that clinicians in the US equated mentally healthy adult behaviour with mentally healthy male behaviour.
This is a form of androcentrism, and shows there is a tendency for women to be perceived as mentally less healthy when they dont show male behaviour. This is called pathologizing women.
Loring and Powell (1988)
research indicated that a psychiatrists gender may influence their ability to diagnose/amount of diagnoses they give.
Random participants 290 male and female psychiatrists to read two case articles of patients behaviour then to diagnose.
When the patients were described as ‘male’ or ‘no info’ was given about gender, 56% were given a diagnosis of scz.
When described as female only 20% were given a diagnosis of scz.
This gender bias was not evident among the female psychiatrists but only the male.
This suggests :
Psychiatrists own gender is influential in diagnosis
Patient own gender is influential
Might also occur due to clinicians not considering that there are gender DIFFERENCES, makes have higher typical levels of substance abuse and females have higher recovery rates and lower relapse rates. These differences influence the validity of diagnoses.
Fischer and Buchanan
Men have been diagnosed with scz much more: 140 : 100, male : female
One explanation for this is that maybe because of sociocultural influences, it is typically believed that women behave with the positive symptoms anyway. Only women used to be able to be diagnosed with ‘hysteria’- female extreme emotion and behaviour, so maybe it is still a natural characteristic assumed of women to be crazed and hysterical.
Cotton (2009)
Says that women are under diagnosed with scz because they have more close relationships so they can get support faster. So women either deal with it better, sooner or just recover faster.
This under diagnosis is still gender biased and means lots of women may be lacking treatement they need.
26
Broverman
Broverman (1970) :
Found that clinicians in the US equated mentally healthy adult behaviour with mentally healthy male behaviour.
This is a form of androcentrism, and shows there is a tendency for women to be perceived as mentally less healthy when they dont show male behaviour. This is called pathologizing women.
27
Loring and powell
Loring and Powell (1988)
research indicated that a psychiatrists gender may influence their ability to diagnose/amount of diagnoses they give.
Random participants 290 male and female psychiatrists to read two case articles of patients behaviour then to diagnose.
When the patients were described as ‘male’ or ‘no info’ was given about gender, 56% were given a diagnosis of scz.
When described as female only 20% were given a diagnosis of scz.
This gender bias was not evident among the female psychiatrists but only the male.
This suggests :
Psychiatrists own gender is influential in diagnosis
Patient own gender is influential
Might also occur due to clinicians not considering that there are gender DIFFERENCES, makes have higher typical levels of substance abuse and females have higher recovery rates and lower relapse rates. These differences influence the validity of diagnoses.
28
Fisher and buchanan
Fischer and Buchanan
Men have been diagnosed with scz much more: 140 : 100, male : female
One explanation for this is that maybe because of sociocultural influences, it is typically believed that women behave with the positive symptoms anyway. Only women used to be able to be diagnosed with ‘hysteria’- female extreme emotion and behaviour, so maybe it is still a natural characteristic assumed of women to be crazed and hysterical.
29
Cotton
Cotton (2009)
Says that women are under diagnosed with scz because they have more close relationships so they can get support faster. So women either deal with it better, sooner or just recover faster.
This under diagnosis is still gender biased and means lots of women may be lacking treatement they need.
30
Studies that q the culture bias in diagnosing scz
Copeland - bias in where psychiatrists r from that affects amount of diagnosis.
Pinto and jones - british with African Caribbean descent 9x more likely to receive diagnosis than white british
Escobar - overinterpretation of symptoms in black british ppl
Whaley - incidents of scz in black Americans are 2% : 1.4% in white Americans
31
Copeland
Copeland (1971) - 134 US and 194 UK psychiatrists received a description of a patient,
Uk - 2% diagnosed
Us - 69% diagnosed.
This suggests a significant difference between countries when it comes to diagnosing scz.
32
Whaley (2004)
Found that incidents of schizophrenia black Americans in comparison to white Americans is greater: 2% : 1.4% , as a result of cultural bias
33
Pinto and jones - 2008
(2008) - They found that British people of African Caribbean descent are 9x more likely to receive a diagnosis than white British people, even though people living in African Caribbean countries are not. This rules out a genetic basis of schizophrenia And is therefore a result of racial bias.
34
Escobar
Escobar (2012) - overinterpretation of symptoms in black british people. This means British African Caribbean people may be discriminated against by a culturally biased agnostic system.
35
What are neural correlates
Neural correlates - patterns or activity in the brain that occur simultaneously with another experience. It is then possibly implicated in the origins of that experience.
36
Dopamine - what is its relevance in scz
Dopamine - neurotransmitter generally causing an excitatory effect, aka reward. High levels of dopamine is associated with schizophrenia. Low levels associated with Parkinson’s.
37
Candidate genes -
Candidate genes - individual genes that may be associated with schizophrenia. Might code for some neurotransmitters associated with dopamine.
38
Concordance rate :
Concordance rate : extent to which first degrees relatives are similar, and liekly to develop a disorder.
39
Studies in support of nurture debate
Loehlin and Nichols (1976) - higher concordance rate seen in MZ twins, may be due to the fact that MZ twins being identical tend to be treated more similarly than dz twins. Therefore nurture may explain high concordance rates not nature.
40
Studies in support of nature debate - genetic base
Kendler - first degree relatives of those with Scz were 18x more likely to develop it. This shows a high concordance rate of scz in families.
Shields (62) - found that concordance rates of scz for MZ twins brought up apart are similar to those brought up together. This suggests it is not due to the environment, but a high genetic influence in scz.
Gottesman (1991) - as genetic similarity increases so does the probability of scz.
MZ twins - 48% risk of developing scz (100% dna)
Dz twins - 17% risk (50%)
41
Kendler - 1985
first degree relatives of those with Scz were 18x more likely to develop it. This shows a high concordance rate of scz in families.
42
Shields (‘62)
Shields (62) - found that concordance rates of scz for MZ twins brought up apart are similar to those brought up together. This suggests it is not due to the environment, but a high genetic influence in scz.
43
Gottesman (91)
Gottesman (1991) - as genetic similarity increases so does the probability of scz.
MZ twins - 48% risk of developing scz (100% dna)
Dz twins - 17% risk (50%)
44
Loehlin and Nichols (1976) -
Loehlin and Nichols (1976) - higher concordance rate seen in MZ twins, may be due to the fact that MZ twins being identical tend to be treated more similarly than dz twins. Therefore nurture may explain high concordance rates not nature.
45
3 possible environmental causes
Some environmental causes:
1. Morgan et al (2017) - birth complications
2. Di Forti et al (2015) - THC strong cannabis in teenage years, even without genetic disposition
3. Morkved et al (2017) - childhood trauma, 67% with scz related to psychotic disorders, reporting at least one trauma. This is in comparison to a matched group with no psychotic disorders.
if trauma did lead to scz then why did 38% who did report a trauma not have a psychotic disorder? This shows it is not guaranteed or deterministic, this means it lacks predictive value because there isnt a secure guarantee in causing of scz and therefore any treatments/Interventions of scz.
what about epigenetics? Can a trauma be passed on? Is that free will?
Also because it is only 67% not 100% concordance rate, then it is a limited explanation as it evidently Is more complex and is influenced by many/other factors.
46
Morgan et al (2017)
Birth complications
Environmental influence
47
Di forti et al (2015)
Di Forti et al (2015) - THC strong cannabis in teenage years, even without genetic disposition
Environmental influence
48
Morkved et al (2017) -
3. Morkved et al (2017) - childhood trauma, 67% with scz related to psychotic disorders, reporting at least one trauma. This is in comparison to a matched group with no psychotic disorders.
Environmental causes
49
What three theories does frith have for cognitive cause of schizophrenia
- filter theory
- dysfunction in cognitive metarepresentation
- central control dysfunction
50
What is friths filter theory
The idea that non-SCZ individuals are able to filter out irrelevant stimuli (images sounds etc) and focus on one thing, filtering out everything else.
SCZ Individuals are unable to filter out other irrelevant auditory stimulus, becoming overwhelmed with sensory information, unable to process and interpret.
51
What symptoms does friths filter theory account for
This might account for symptoms such as speech poverty
Might also account for auditory hallucinations?
52
Explain friths idea about conscious processing
Link to scz
Conscious processing = the highest Level of cognitive functioning takes place, and we are aware of this. However this has a limited capacity so we can only carry out one task at a time.
- only important information goes into the conscious awareness
- for scz people the attentional filter breaks down, meaning the unimportant information enters the conscious for scz.
-Therefore the mind of scz think everything has to be attended to.
53
Explain friths idea about preconscious processing
Link to scz
Preconscious processing = we are unaware of this as it is an automatic process, and we carry out many tasks at one time.
- only important information goes into the conscious awareness
- for scz people the attentional filter breaks down, meaning the unimportant information enters the conscious for scz.
-Therefore the mind of scz think everything has to be attended to.
54
How does friths theory of conscious and preconscious process explain auditory hallucinations in scz
For AUDITORY HALLUCINATIONS: FRITH
when SCZ are bombarded with sounds, and our our preconscious filter is defective, meaning all sounds are recognised as significant and reach the conscious level of processing.
They would misinterpret non speech sounds as speech and might mistake them for voices.
55
What are two types of dysfunctional thought processing that frith identifies in scz
Metarepresentation
Central control dysfunction
56
What is metarepresentation
(Who thought of it aswell)
2: METAREPRESENTATION
= the cognitive ability to differentiate between our own actions/thoughts and actions of others.
Frith
57
How does metarepresentation link to scz according to frith
Schizophrenics may experience a dysfunction in this area, meaning they may be unable to differentiate their own thoughts and accidentally believe they are somebody else’s. >
This might lead to hallucinations or delusions, specifically thought insertion delusions ( thinking we are hearing voices but it is our own though )
58
One study supporting filters theory of metarepresentation in scz
Bental et al (91) found that SCZ struggled to identify words belonging to a certain category, such as birds that they had seen before, drawn themselves or had not seen before.
They are unable to recognise their own output - Dysfunction in metarepresentation, support of frith
59
Bental (1991)
Bental et al (91) found that SCZ struggled to identify words belonging to a certain category, such as birds that they had seen before, drawn themselves or had not seen before.
They are unable to recognise their own output - Dysfunction in metarepresentation, support of frith
60
What is central control
Who thought of it
Frith
CENTRAL CONTROL DYSFUNCTION
Your central control is linked to cognitive functions that suppress automatic responses, whilst we perform deliberate actions.
61
What is central control dysfunction
How does it explain scz
Having a dysfunction in your central control is linked to SCZ because it means an inability to to suppress these automatic thoughts and speech triggered by stimuli, derailing their thoughts and sentences.
Frith links this to speech poverty, when scz show word salads and lack of fluent sentences.
62
What does the biological explanation for scz think causes it
(2)
Neural correlates
Candidate genes
63
What is a neural correlate
Link to explaining scz
Neural correlates - patterns or activity in the brain that occur simultaneously with another experience. It is then possibly implicated in the origins of that experience.
Disbalance of dopamine levels in the brain (could be high or low amounts) have been correlated to scz, implicated in causing it.
64
Two weaknesses of neural correlates
X : not causational but correlational
X : Problem of chicken and the egg - not necessarily that the brain activity causes SCZ, but SCZ might cause brain activity.
65
What is dopamine
Why is dopamine associated with schizophrenia
neurotransmitter generally causing an excitatory effect,
aka reward. High levels of dopamine is associated with schizophrenia. Low levels associated with Parkinson’s.
66
What is a candidate gene
Why is it associated with scz
Candidate genes -
A gene associated with a trait/condition
individual genes that may be associated with schizophrenia. Might code for some neurotransmitters associated with dopamine.
67
What is concordance rate
Link to scz
Concordance rate : extent to which first degrees relatives are similar genetically, and liekly to develop a disorder.
Usually measured in twins that either have 50/100% shared genetic material.
If someone is similar genetically or a close relative to someone with scz they might have a higher chance of also having that disorder.
68
Kendler (1985)
Kendler (1985) - first degree relatives of those with Scz were 18x more likely to develop it. This shows a high concordance rate of scz in families.
69
Shields (1962)
Shields (62) - found that concordance rates of scz for MZ twins brought up apart are similar to those brought up together. This suggests it is not due to the environment, but a high genetic influence in scz.
70
Gottesman (1991)
Gottesman (1991) - as genetic similarity increases so does the probability of scz.
MZ twins - 48% risk of developing scz
Dz twins - 17% risk
71
Loehlin and Nichols (1976)
Loehlin and Nichols (1976) - higher concordance rate seen in MZ twins, may be due to the fact that MZ twins being identical tend to be treated more similarly than dz twins. Therefore nurture may explain high concordance rates not nature.
Not necessarily biology basically
72
Three studies that support a genetic cause of scz
Kendler (1985) - first degree relatives of those with Scz were 18x more likely to develop it. This shows a high concordance rate of scz in families.
Shields (62) - found that concordance rates of scz for MZ twins brought up apart are similar to those brought up together. This suggests it is not due to the environment, but a high genetic influence in scz.
Gottesman (1991) - as genetic similarity increases so does the probability of scz.
MZ twins - 48% risk of developing scz (100% dna)
Dz twins - 17% risk (50%)
73
Study that supports environmental cause over biological cause of scz
Loehlin and Nichols (1976) - higher concordance rate seen in MZ twins, may be due to the fact that MZ twins being identical tend to be treated more similarly than dz twins. Therefore nurture may explain high concordance rates not nature.
74
Tienari et al (2004)
Tienari et al (2004) - Biological parents of kids with scz are at heightened risk, shows a lack of environmental risk. This shows a predisposition to scz, that the environment didnt buffer the probability.
75
Three studies that depict three different environmental causes of scz
1. Morgan et al (2017) - birth complications
2. Di Forti et al (2015) - THC rich cannabis in teenage years, even without genetic disposition
3. Morkved et al (2017) - childhood trauma, 67% with scz related to psychotic disorders, reporting at least one trauma. This is in comparison to 38% of a matched group with no psychotic disorders. Matched them with the severity of SCZ.
76
Morgan et al (2017)
Birth complications increase likelihood of scz in the offspring
77
Di forti et al (2015)
THC rich cannabis in teenage years, even without genetic disposition increases likelihood of scz
78
Morkved et al (2017)
Morkved et al (2017) - childhood trauma,
67% with scz related to psychotic disorders, reporting at least one trauma.
in comparison to 38% reporting a trauma of a matched group with no psychotic disorders. Matched them with the severity of SCZ.
79
3 limitations of Morkved et al
if trauma did lead to scz then why did 38% who did report a trauma not have a psychotic disorder?
1. Predictive value is low
This shows it is not guaranteed or deterministic, this means it lacks predictive value because there isnt a secure guarantee in causing of scz and therefore any treatments/Interventions of scz.
2. Limited explanation
only 67% not 100% concordance rate, then it is a limited explanation as it evidently Is more complex and is influenced by many/other factors.
3. what about epigenetics? Can a trauma be passed on? Is that free will?
80
Polygenic meaning
Link to scz
That there isnt one type of candidate gene for a disorder/condition
There are multiple different genes
Therefore there are multiple genes that can code for schizophrenia
81
Study for schizophrenia being polygenic and aetiologically heterogeneous
Ripke et al (2014) - meta analysis
Looked at pre existent genome studies of scz. This was 37,000 people with scz in comparison to a control group of 113,000.
They found 108 separate genetic variations that were associated with increased risk of scz.
This shows that scz is aetiologically heterogeneous - there isnt one combination of polygenic genes, it is differnt combinations for different people.
82
Aetiologically heterogeneous meaning
Link to scz
= not one combination of polygenic genes in scz but lots of possible combinations for different people
Supported by Ripke who found that there are up to 108 genetic variations in increasing likelihood of having scz
83
Ripke (2014)
What does it show
Ripke et al (2014) - meta analysis
Looked at pre existent genome studies of scz.
This was 37,000 people with scz VS control group of 113,000.
They found 108 separate genetic variations that were associated with increased risk of scz.
This shows that scz is aetiologically heterogeneous - there isnt one combination of polygenic genes, it is differnt combinations for different people.
84
Two limitations of Ripke et al
1. Predictive value
This means scz has low predictive value/validity because there are so many different genes as well as combinations that could code for scz.
2. Not a rounded explanation
Why is it 0.7% > the missing .3 might be accounted for by environmental factors like THC consumption or childhood trauma.
85
What is the role of mutation in causing scz idea
Supporting studies?
That idea that if your genetic material is mutated, by radiation poisoning or infection, it is correlated with increased right of scz
Brown et al
Under 25 men : 0.7% chance of scz
Over 50 men : 2% chance of scz
86
Brown et al (2002)
One limitation of this
Brown et al (2002)
increased risk of sperm mutation (which increases naturally with age) correlates with an increased risk of scz.
Fathers under 25 had a 0.7% of scz.
Fathers over 50 had a 2% chance of scz.
1. Limited explanation
Why is it 0.7% > the missing .3 might be accounted for by environmental factors like THC consumption or childhood trauma.
87
One useful application of biological explanation of scz
Genetic counselling
One application of understanding the likely role of genes in scz is genetic counselling.
- genetic counselling is basically when you can see an infants genes to see what potential conditions they might be born with.
88
What is hyperdopaminergia
Hyperdopaminergia - ‘hyper’ = lots of
This is when an excess of dopamine or dopamine receptors in pathway from the sub (sub meaning below) cortex to Broca’s area, the frontal lobe, which might be responsible for speech poverty or auditory hallucinations in scz
89
What is hypodopaminergia
- ‘hypo’ = lower
This is when there is lower amounts of dopamine or dopamine receptors in the prefrontal cortex, which is associated with decision making and impulsivity, can lead to cognitive problems.
90
Problem with hyperdopaminergia and hypodopaminergia
chicken/egg? we do not know if it scz causes the dopamine changes or the changes causing scz. Unclear.
91
Three medicines for scz
L-Dopa - increases dopamine
Amphetamines - really strong stimulant drugs that are excitatory
Antipsychotics - inhibit dopamine
92
Three medicines for scz
1.L-Dopa - increases dopamine
2. Amphetamines - really strong stimulant drugs that are excitatory
3. Antipsychotics - inhibit dopamine
93
What is L-Dopa
What does it do
given to sufferers of Parkinson’s, which is caused by low levels of dopamine
L-Dopa therefore increases levels of dopamine
94
What are amphetamines
What do they do
stimulant drugs that are excitatory and speed up messages between your brain and body
This increases dopamine, worsening symptoms.
Curran et al - amphetamines are so strong that it can induce scz in people without it
Tenn et al - amphetamines induced scz like symptoms in rats, and then relieved those symptoms using drugs that reduce dopamine
95
What are antipsychotics and what do they do
Tauscher et al (2014) antipsychotics decrease dopamine and reduce symptoms
96
Curran et al (2004)
Curran et al (2004) : amphetamines are so strong it can induce scz in people without it
Ampetamines increases dopamine - so it shows that increased dopamine does correlate to schizophrenia
97
Tenn et al (2003)
Tenn at al (2003): induced scz like symptoms in rats using amphetamines, and then relieved those symptoms using drugs that reduce dopamine actions, supporting dopamine hypothesis.
98
Tausher et al (2014)
3. Tauscher et al (2014) antipsychotics decrease dopamine and reduce symptoms
4. Some candidate genes act on the production of dopamine like D receptors.
99
Seeman (1987)
scz people have increased dopamine receptor density rather than increased levels of dopamine in their body.
Dopamine receptor density means they have an increased sensitivity to dopamine.
This is more than 2x normal amount (60% - 110%)
100
Alternative to dopamine hypothesis
McCutcheon et al (2020) - using post mortem and live Brian scans, found raised levels in several brain regions of scz patients of glutamate.
Several candidate genes (Ripke - 108 candidate genes for SCZ) also code for glutamate.
101
McCutcheon et al (2020)
McCutcheon et al (2020) - using post mortem and live Brian scans, found raised levels in several brain regions of scz patients of glutamate.
Several candidate genes (Ripke - 108 candidate genes for SCZ) also code for glutamate.
M
102
Name Friths dysfunctional thought processing theories
1. Friths faulty filter theory
2. Metarepresentation
3. Central control dysfunction
103
Outline Friths filter theory as an explanation for scz
Seven key words
1. Friths faulty theory
We have ‘attentional filters’
- non-SCZ individuals are able to filter out irrelevant stimuli (images sounds etc) and focus on one thing, filtering out everything else.
- SCZ Individuals are unable to filter out other irrelevant auditory stimulus, becoming overwhelmed with sensory information, unable to process and interpret.
He then distinguishes between conscious and preconscious processing
Conscious processing = the highest Level of cognitive functioning takes place, and we are aware of this. However this has a limited capacity so we can only carry out one task at a time.
Preconscious processing = we are unaware of this as it is an automatic process, and we carry out many tasks at one time.
He states that usually only important information goes into the conscious awareness but for scz people the attentional filter breaks down, meaning the unimportant information enters the conscious for scz. Therefore the mind of scz think everything has to be attended to.
- Frith argues this is how delusions occur, specifically thought insertion, and might account for auditory hallucinations.
104
Outline Friths theory of metarepresentation as an explanation for scz
Four kw
2: METAREPRESENTATION
= the cognitive ability to differentiate between our own actions/thoughts, output and actions of others.
Schizophrenics may experience a dysfunction in this area, meaning they may be unable to differentiate their own thoughts and accidentally believe they are somebody else’s. >
This might lead to hallucinations or delusions, specifically thought insertion delusions ( thinking we are hearing voices but it is our own thoughts )
105
Supporting evidence for metarepresentation
Bental et al (91) found that SCZ struggled to identify words belonging to a certain category, such as birds that they had seen before, drawn themselves or had not seen before.
They are unable to recognise their own output - Dysfunction in meta-representation, as they don’t recognise their own drawings (output) which is support of frith
106
Bental (1991)
Bental et al (91) found that SCZ struggled to identify words belonging to a certain category, such as birds that they had seen before, drawn themselves or had not seen before.
They are unable to recognise their own output - Dysfunction in meta-representation, as they don’t recognise their own drawings (output) which is support of frith
107
108
Outline friths theory of central control dysfunction
Seven kw
Your central control is linked to cognitive functions that suppress automatic responses, whilst we perform deliberate actions.
Having a dysfunction in your central control is linked to SCZ because it means an inability to to suppress these automatic thoughts and speech triggered by stimuli, derailing their thoughts and sentences.
Frith links this to speech poverty, when scz show word salads and lack of fluent sentences.
109
Supporting evidence for central control dysfunction
Stirling et al :
tested stroop test on scz and non scz, and it took over 2x longer for scz to complete it. This is good evidence for central control dysfunction because it shows their ability to suppress automatic response when doing deliberate actions is much slower.
110
What is the stroop test
This is found using the Stroop test, when you have to, under timing, read out the colours of words but they are typed in different colours than what they are. EG:
Red. Blue. Purple. Green
111
Stirling et al
tested stroop test on scz and non scz, and it took over 2x longer for scz to complete it. This is good evidence for central control dysfunction because it shows their ability to suppress automatic response when doing deliberate actions is much slower.
112
4 strengths of the cognitive psychological explanation for scz
Strengths
1. It explains different symptoms clearly - face validity
2. Strong supporting evidence - central control dysfunction (stroop test Stirling et al)
3. Cognitive treatement works better than biological treatment - means the cognitive explaiantion is stronger.
4. NICE (National institute for care) et al (2014) did a meta analysis of CBTp (CBT for psychosis patients), and found it was more effective than antipsychotic meds.
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Outline four limitations of the cognitive psychological explanation
1. There isnt one theory of dysfunctional thought processing explains all of them
2. It doesnt explain why the delusions (voices they hear) are negative abusive or suggest reprehensible acts.
3. Cognitive study support is reliant on inferences, unproved and correlational and
4. Cognitive factors are unable to provide a distal explanation for scz like biological.
Distal explanation - root/cause explanation
Proximal - what directly causes something
Cognitive provides a proximal explanation:
Eg: faulty filter > hallucinations
However a distal explanation is better because it provides the first cause: this is better cause knowing jsut that there is a faulty filter isnt enough, we need to know what causes this.
Eg: dopamine levels in brain, neural correlates > faulty filter > hallucinations
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What is the difference between distal and proximal explanations
Distal explanation - root/cause explanation
Proximal - what directly causes something
Cognitive provides a proximal explanation:
Eg: faulty filter > hallucinations
However a distal explanation is better because it provides the first cause: this is better cause knowing jsut that there is a faulty filter isnt enough, we need to know what causes this.
Eg: dopamine levels in brain, neural correlates > faulty filter > hallucinations
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