component 3 Flashcards
stress
psychological and physical strain or tension generated by events or experiences that are difficult to manage or endure
yerkes dodson law
in order to gain the best performance, you need an optimum amount of stress.
however, too much or not enough stress leads to weak performance
stress as a physical response
Selye (1936) conducted research on rats and described a general phsyical response which activates the nervous system to release hormones such as cortisol and adrenaline
stress as a psychological response
Lazarus and Folkman (1984) proposed a transactional model of stress. stress is seen as an interaction between an individual and the enviroment.
when a person percieves a stressor, they make a judgement on whether they can cope
primary appraisal (Lazarus and Folkman 1984)
considers whether the threat is harmful or challenging
secondary appraisal (Lazarus and Folkman 1984)
considers whether there is resources to deal with it
acute stress
response to an immediate stressor e.g. exams
episodic acute stress
repeated instances of short term stress, can become part of personality or lifestyle
chronic stress
persists over a long period of time, can see no escape e.g poverty or relationship problems
Farr and Gibbons (1990)
7 types of crime: property predatory, property fraudulent, transactional vice, interpersonal violence, interpersonal sexual violence, order disruption, folk/mundane crimes
Raine (1993) concordance rates
52% for MZ twins and 21% for DZ twins
Brunner et al (1993)
DNA analysis of 28 male members of a Dutch family who had violent behaviour and found the men shared a gene that led to low MAOA
SAM pathway
- threat (ongoing evaluation)
- hypothalamus activated
- sympathetic branches of ANS activated
- adrenal medulla releases adrenaline and noradrenaline
- when threat is gone, parasympathetic branch of NS dampens response
SAM pathway
- threat (ongoing evaluation)
- hypothalamus activated
- sympathetic branches of ANS activated
- adrenal medulla releases adrenaline and noradrenaline
- when threat is gone, parasympathetic branch of NS dampens response
strengths of biological explanation of stress
Leor et al (1996)- more deaths caused by cardiovascular problems on the day of the northridge california earthquake. realistic study, better than conducting acute stressor in a lab so more ecologically valid
adrenaline released during acute stressors can have negative effects on the heart. sudden release of adrenaline leads to bottom part of the heart to be paralysed so the top half has to work harder. this demonstrates acute effects on the body after stress which links together adrenaline and death
weaknesses of biological explanation of stress
dimsdale (2008): other factors may be involved in the causes of cardiovascular problems as other factors may be involved too —> can’t isolate stress alone.
taylor et al (2000) women use tend and befriend rather than fight or flight. during EEA, adaptive for women to deal with stress by nurturing their young and creating social networks and fight and flight puts risk to their young. oxytocin is higher in women. weakness because it’s not a single response, there is a gender difference
sutherland (1949)
boys socialised to be risk takers, tough whereas girls are socialised to be conforming, talk about feelings and supervised and controlled
cohen (1955)
social learning theory harder for boys because girls have easy access to mothers, whereas fathers have traditionally been elusive role models as theyre less frequently available for their sons
boys engage in “compensentory compulsory masuclinity” through aggression and antisocial behaviour which causes delinquency, as boys rebel against socialisation from mothers
weaknesses of social psychological explanation of criminal behaviour: gender socialisation
- chivalry hypothesis- more women commmit crimes than official statistics suggest. police, magistrates, judges tend to be men and men are socialised to be more chivalrous. pollak- (1950) men in justice system have prpotective attitude towards women. suggests that its not only gender of criminal, also gender of criminal justice system –> lacks validity
- gender difference could be explained through biology rather than social factors. testosterone secreted in much higher levels in men. dabbs et al (1987) —> 9/10 inmates with lowest testosterone concentrationshad committed non violent crimes, 10/11 inmates with high t conc had committed violent crimes. testosterone sugg to increase aggression. female oestridol promotes empathy which is lacked in criminals. weakness because reductionist explanation.
application of gender socialisation
man up project, males could socialise differently to reduce crim b ehaviour. e.g could be exposed to more feminine strategies of conflict management. positive effect on recidivism.
differential association theory
people vary in the frequency with which they associate with others who have more or less favourable attitudes towards crime. these attitudes will influence their own attitudes and behaviour. proposed by sutherland.
a child learns attitudes to crime, e.g. whether it is desireable or not. also learns methods for committing crimes.
strengths of differential association theory
- it changed peoples views of criminal behaviour. marked a shift from blaming the individual to including social factors. theory stated that criminal behaviour didnt need to be explained in terms of criminal activity, but in terms of social experiences. in terms of applications, we can attempt to change the learning environments.
- criminality appears to run in famillies. osborn and west (1979) found that when a father was criminal, 40% of sons had also committed a crime by the age of 18 compared to 13% of non criminal fathers.
SEEW strength of role of adrenaline and acute stress
S- evidence has high ecological validity
E- Leor et al (1996) found that cardiovascular deaths increased on the day of the Northridge california earthquake
E- ecologically valid because the earthquake was a naturally occurring stressor, rather than one artificially created in a lab
W- strength because it highlights how the biological explanation of stress applies to real life explanations (creates link between adrenaline and death), making it more generalisable than laboratory studies.
SEEW weakness of adrenaline and acute stress
S- a weakness is raised by Dimsdale (2008), who argues that stress cannot be definitively identified as the sole cause of cardiovascular problems
E- other factors such as cholesterol levels or smoking could also play a significant role in cardiovascular risk
E- this means that the relationship between stress and cardiovascular issues is not clear cut, as biological stress responses might interact with other stress and lifestyle factors
W- this is a weakness because it decreases the validity of the biological explanation by suggesting that stress alone might not be sufficient to account for cardiovascular issues
SEEW strength of role of cortisol in chronic stress
S- evidence shows that cortisol released during prenatal stress has long lasting effects on a developing foetus
E- O’Connor et al found that maternal stress during pregnancy altered the HPA axis functioning of the child, while Sarkar (2007) showed that higher cortisol levels in the mothers blood correlated with poorer cognitive and behavioural development in the child
E- this means that the biological explanation effectively accounts for how cortisol, a key stress hormone, can influence long term physical and mental health
W- this is a strength because it provides evidence on the measurable effects of cortisol, supporting the biological explanations validity and real world relevance.
SEEW weakness of cortisol explanation
S- a weakness is the lack of clear cause and effect relationship between stress and cortisol release
E- when stressed, people may change their eating habits, sleep less, or consume more alcohol and caffeine, which could contribute to illness attributed to stress
E- this means that negative outcomes linked to cortisol might not be entirely due to stress but could result from confounding lifestyle factors
W- this is a weakness because it reduces the internal validity of the biological explanation by making it harder to isolate cortisols specific effects meaning it cant be used to explain stress related illnesses e.g. heart disease, type II diabetes
SEEW strength of hardiness explanation
S- a strength is its high usefulness when being applied to stress management
E- Maddi et al (1988) demonstrated the benefits of hardiness training, where participants who underwent hardiness training showed increased job satisfaction and decreased anxiety and illness compared to those who learned relaxation skills or were in the control group
E- this means that hardiness training equips individuals with strategies to view stress as something manageable, helping them to take control and remain committed and resillient during stress
W- this is a strength because it shows the effectiveness of hardiness in improving real world outcomes such as workplace productivity and mental health whilst approaching stress management.
SEEW weakness of the hardiness explanation
s: A weakness of the hardiness explanation is its reliance on self-report questionnaires, which are prone to social desirability bias.
E: Funk (1992) argued that many hardiness scales are ambiguous and inconsistently applied across studies, meaning that differences in findings may be due to the measurement tools rather than the hardiness traits themselves.
E: This means the explanation may lack validity, as it is difficult to accurately measure hardiness traits or their influence on stress outcomes. Additionally, participants may give answers they think are socially acceptable, rather than reflecting their true feelings or experiences.
w: This is a weakness because it reduces the reliability of the research underpinning the hardiness explanation and makes it harder to draw consistent conclusions about its role in stress management.
SEEW strength of type A and B personality
S: evidence linking Type A personality traits to physiological stress responses.
E: Friedman et al. (1975) participants with Type A personalities showed higher adrenaline levels and more stress in challenging situations, such as completing an impossible puzzle in a noisy environment, compared to Type B individuals.
E: Type A individuals are more prone to chronic stress-related health issues, such as cardiovascular disease, due to their constant activation of the sympathetic-adrenal-medullary (SAM) pathway.
W: provides physiological evidence to support the theory, showing how personality traits directly impact stress responses and health outcomes.
SEEW weakness of type A and B
S: cultural and gender bias.
E: Helman (1987) noted that the Type A traits, such as competitiveness and being a workaholic, reflect Western cultural norms, which are not universally applicable. Additionally, the original studies focused on men, and while Baker et al. (1984) found that women also showed Type A traits, women’s stress responses often differ (e.g., “tend and befriend”).
E: the findings may not generalise to non-Western cultures or to women, whose stress responses may be shaped by different social and biological factors.
W: limits the universality of the Type A and B explanation, reducing its applicability to diverse populations and situations.
SEEW strength of life events
S: A strength of the life events explanation is the evidence linking life changes to biological susceptibility to illness.
E: Cohen et al. (1993) found that participants with higher life events scores were more likely to develop a cold after being exposed to the cold virus.
E: This suggests that the experience of significant life events can lead to biological changes that weaken the immune system.
W: This is a strength because it provides scientific, objective biological evidence, supporting the idea that stress from life events is more than just psychological and has physical health consequences.
SEEW weakness of life events
S: A weakness of the life events explanation is its reliance on self-report measures
E: ther ssrs is in the form of a questionnaire, which means that the data used to measure the relationship between life events and stress may not always be reliable as participants may forget or misremember significant life events
E: Raphael et al. (1991) found that when women were asked to recall life events over a 10-month period, only a quarter of the events they initially reported appeared on later lists. This highlights issues with memory and accuracy in recalling life changes.
W: This is a weakness because it reduces the internal validity of the research, making it harder to draw accurate conclusions about the connection between life changes and stress.
SEEW strength of daily hassles
S: the evidence showing a clear relationship between hassles and negative health outcomes.
E: Bouteyre et al. (2007) found that 41% of students transitioning from school to university experienced depressive symptoms, which were strongly correlated with daily hassles. Sher (2004) also found that daily hassles increased cortisol levels, a biological marker of chronic stress.
E: This suggests that the cumulative effect of daily hassles can significantly impact both mental health and physiological responses, demonstrating the relevance of this theory in explaining stress.
W: This is a strength because it highlights the importance of everyday experiences in contributing to stress, relatable perspective than life events, which may be less frequent.
weakness of daily hassles
self report measures used, hassles scale doesnt give individuals the option to report that a hassle has occurred but didnt bother them, may also underreport due to social desirability bias
reduces internal validity
strength of hardiness
practical applications, maddi et al (1988) benefits if hardiness training, ppts who did hardiness showed increased job satisfaction and decreased anxiety compared to those who learned relaxation skills or were in the control group. hardiness training equips individuals with strategies to view stress as something manageable, helping them take control and remain committed and resillient in face of stress. shows how hardiness can increase workplace productivity and mental health
weakness of hardiness
self report questionnaires, funk (1992) many hardiness scales are ambiguous and inconsistently applied across studies so differences in findings may be due to the measurement tools used rather than the hardiness traits themselves
so may lack validity, as its difficult to accurately measure traits. ppts may also give answers that they think are socially acceptable rather than reflecting their true feelings
harder to draw conclusions, lower population validity
strength of type A and B
evidence linking type A to psychological stress responses, Friedman et al (1975) found that ppts with type A personalities showed higher adrenaline levels and more stress in challenging situations e.g. completing an impossible puzzle in a noisy environment compared to type B individuals
suggetss that type A are more prone to stress related illnesses e.g. cardiovascular disease due to the constant activation of the SAM pathway. provides physiological evidence to support the theory, shows direct link between type A personalities and stress related illnesses
weakness of type A and B
cultural and gender bias, helman (1987) noted that type A traits e.g. competitiveness and being a workaholic reflect western cultural norms which are not universally applicable. additionally, the original studies focused on men but baker et al (1984) found that women also show type A traits but womens stress responses often differ “tend and befriend”. shows that the findings may not generalise to non western cultures or women whose stress responses may be shaped by different social and biological factors which reduces pop validity and applicability
strength of differential association theory (psychological)
ability to explain how criminal behaviour is learned through social interactions. Akers et al (1979) surveyed 2500 adolescents and found that peer influence, including differential reinforcement and imitation accounted for 68% of the variance in marijuana use and 55% alcohol use.
criminal behaviour can be attributed to social environments e.g. peers who promote offending
allows practical strategies to be made for reducing crimes through interventions targeting social influences
weakness of differential association theory
much of the supporting evidence is correlational. cox et al (2014) difficult to establish whether individuals adopt crim behaviour from their peers or whether they seek out others with similar tendencies.
theory cannot show cause and effect, so cant conclusively determine whether socialisation causes criminal behaviour or reflexts pre existing tendancies so reduces reliability of research
strength of gender socialisation
explanation of gender differences in crime rates. dabbs et al (1987) inmates with the highest testosterone levels were more likely to have committed violent crimes, whereas those with the lowest levels had committed non-violent crimes.
means that biological differences, influenced by gender socialisation, may predispose men to higher aggression levels. strength because it means that the theory is supported by biological factors too so shows nature and nurture
weaknesses of gender socialisation
lack of consistent evidence supporting the chivlary hypothesis. carlen (1997) women who adhered to traditional gender roles such as being good mothers were less likely to be imprisoned, but this was not always linked to the severity of their offences. means that the justice system may not always treat women leniently, as other factors such as class or race may influence sentencing decisions. reduces generalisability of the research
weakness of the amygdala
oversimplifies by ignoring other brain regions. raine et al (1997) while murderers had higher glucose metabolism in their amygdala, they also showed abnormally low activity in their prefrontal cortex- an area which regulates impulsive behaviours and self control.
means that aggressive criminal behaviours cannot be attributed solely to the amygdala, but its interaction with other brain reigons like the orbitofrontal cortex
shows reductionist nature of the explanation
strength of the amygdala
high predictive validity. padroni et al (2014) longitudinal study of 503 males, finding that those with smaller amygdala volumes exhibited higher levels of aggression and psychopathic traits throughout their lives and at follow up assessments
means the amygdala may be a biological indicator of an individuals likelihood to engage in criminal behaviour over time which shows evidence to support the role of biological factors in predicting criminal behaviours, allowing for early interventions
strength of inherited criminality
evidence supporting genetic link, mednick et al (1987) found that 20% of adoptees whos biological parents were criminals went on to commit crimes compared to only 15% of those adopted into criminal famillies suggesting a stronger influence of genetics
weakness of inherited criminality
inability to explain all types of crime. tilhonen et al (2015) found that individuals with a defenctive MAOA gene were 13 times more likely to engage in repeated violent behaviours but not all individuals with this gene became criminals. means that the biological explanation struggles to account for non-violent crimes and requires interaction with the environment to fully explain criminal behaviour. reductionist explanation, and limits applicibility because it doesnt account for crimes such as fraud or theft.
strength of eysenck
evidence that personality has a genetic basis. zuckerman (1967) found +0.52 correlation for neruroticism in MZ twins compared to +0.24 in DZ twins, and a +0.51 correlation for extraversion in MZ twins compared to +0.12 in DZ twins
means that personality traits linked to criminal behaviour such as neuroticism and extraversion may have a significant genetic component. supports biological aspect of eysencks theory, highlighting role of inherited personality traits in criminal behaviour
another strength of Eysenck
ability to predict delinquent behaviour, dunlop et al (2012) extraversion and psychoticism, along with lie scales, were good predictors of minor delinquent behaviour such as theft and traffic offences among students.
means that personality traits developed by Eysenck can help in less serious, rule breaking behaviour particularly in younger individuals. can prevent early delinquency
weakness of eysenck
doesnt account for environmental factors, van dam et al (2007) only a small number of offenders in juvenile detention centres exhibited all three of eysencks variables
theory may overlook importance of external influences, such as upbringing and peer relationships in shaping criminal behaviour. limits predictive validity, fails to provide a complete explanation
strength of minimalisation
evidence supporting role, kennedy and grubin (1992) found that sex offenders often downplayed their crimes, blaming the victim or denying their involement altogether. maruna and mann (2006) argued that this behaviour aligns with normal psychological processes as people externalise blame
means that distorted thinking, e.g. minimisation, may help offenders justify their actions reducing guilt. strength because it shows how cognitive processes can influence criminal behaviour and provides a focus for interventions such as CBT.
strength of hostile attribution bias
evidence supporting role. Schoenberg and gusty (2014) showed emotionally ambiguous faces to 55 violent offenders in prison and matched to “normal” controls. the offenders were more likely to interpret neutral expressions as expressions of aggression.
means that offenders with hostile attribution bias are likely to misinterpret non-aggressive cues as threatening, which could lead to impulsive or violent actions. highlights how cognitive distortions may play a key role and allowes for interventions such as anger management.
weakness of cog factors
relies heavily on kohlbergs stages of moral reasoning. krebs and denton (2005) argue that moral principles are only one key factor affecting behavuour, and they are often used to justify actions rather than guiding behaviour in the first place. additionally, his theory is gender biased focusing on male perspective and ignoring potental gender differences
means that the theory is reductionist and could oversimplify the role of moral reasoning in crim behaviour and fail to account for other influences e.g. emotions or situational factors. undermines validity
kuhlmann et al (2005)
cortisol impairs memory, in particular the retrieval of negative words. shows stress hormones do affect cognitive functions and that emotional material is especially sensistive to the memory modulating effects of stress hormones
kiecolt glaser (1984)
stress reduces immune functioning by measuring a decrease in natural killer cell activity medical students during exams.
who proposed hardy personality
kobasa
what three characteristics do poeple with the hardy personality have
committment control and challenge
committment
reflects engaged attitude towards life, individuals find meaning even in stressful situations
control
believe they can influence events rather than being passive victims of stress.
challenge
viewing stressors as opportunities for growth rather than threat
what do challenge commitment and control act as
a buffer against stress by fostering resillience helping hardy individuals adopt active coping strategies.
bartone (1999)
soldiers with high hardiness experienced fewer negative health effects, e.g. ptsd and depression, even under significant stress
kobasa et al (1986)
hardy personality more effective stress buffer than exercise or social support. suggetss the three cimponents of hardiness significantly mitigate the negative physical and emotional consequences of stress
strength of beta blockers
beta blockers are proven to help the nerves of musicians
neftel et al (1982) took a group of musicians and gave them either beta blockers or a placebo 6.5 hours before they were performing, and found that the beta blocker group had a lower heart rate and more accuracy in playing complex instruments than the placebo group. they also had reduced stage fright.
this means that beta blockers target the physiological symptoms of stress e.g. heart rate and muscle tension which allows them to perform more effectively
this is a strength because it provides evidence on the versatility of beta blockers, showing that they can be used for off label uses such as for musicians which broadens their real world applicability.
weakness of beta blockers (different types)
different types of beta blockers have different effects on stress. schweizer et al (1991) compared different beta blockers to a placebo for students takimng a maths test. and found that although all beta blockers helped reduce physical effects, there were different ratings in stress among the group. this means that beta blockers dont help to show cause and effect as they dont have a uniform effect across all types.
W- this is a weakness because it limits the reliability of beta blockers as a universal treatment for stress.
weakness of beta blockers (long term)
poor long term effectivity, beta blockers dont address the psychological and emotional side of stress e.g. irrational thoughts or situational pressures
this means that if the person is irrational or has a strong tupe A personality then this is untreated. sit may be more appropriate for long term coping
weakness because sit is needed long term to treat the cause and drug therapy is only. effective short term
strength of SIT
evidence of effectiveness in reducing anxiety and stress and increasing performance
sheehy and horan 92004) first year law students and did 4 weekly sessions of SIT for 90 minutes. ppts who had sit had lower anxiety levels. academic performance of those predicted to be in bottom 20% also had signficant improvements after sit
E- sit is useful in addressing both the emotional and cognitive aspects of stress and equips individuals with coping strategies to allow them to manage stress better.
W- strength because it demonstrates the practical, long term benefits of sit in real world contexts such as education
weakness of sit
difficulty to pinpoint which of the three components is the effective part since they overlap. Moses and Hollandsworth (1985) randomly allocated 24 dental phobics to one of 4 conditions. found that some had stage one, whereas others had stage one along with other elememts and coping skills training
this means that its hard to isolate which part of the therapy had the most signiifcant impact since iot could be the initial conceptualisation stage or skills acquisition and application.
reduces psychologists ability to improve or refine sit making the therapy potentially less efficient.
schizophrenia
a long term, major psychotic disorder that is typified by a lack of contact with reality.
roughly 220,000 diagnosed each year in england and wales , and in the UK and europe ICD-10 is used to diagnose.
schneider (1959)
positive symptoms (in addition to normal behaviours) and negative symptoms (inhibit people from ‘normal’ behaviour)
hallucinations
unreal perceptions that can present themselves in any sense, 20% have tactile hallucinations
delusions
beliefs that are unreal, common delusions include persecution (person or group want to hurt the individual) and grandiosity (special or more powerful)
disordered thinking
thoughts and discourse seem to jump from one topic to another, with no logical flow
alogia
poverty of speech, reduction in total speech produced lacking meaning
flatness of affect
shows no emotion, little to no facial expressions
avolition
individual is indifferent to their surroundings, no desire to take part in activities
diathesis stress
diathesis = biological disposition
stress = psychological stressors
a person may be able to develop schizophrenia, but it only onsets if they are stressed
dopamine hypothesis
initially proposed that too much dopamine led to schizophrenia, Griffith et al (1968) induced schizophrenic symptoms in non schizophrenic volunteers by giving them dextroamphetamine to increase dopamine levels in the brain. they then experienced an abrupt onset of paranoid delusions and were cold and detatched emotionally. later this was proven to be too simple, as giving drugs to lower dopamine levels had little to no effect on schizophrenic patients who had mainly negative symptoms.
dopamine receptors
D1-D5 then discovered, distributed across the cerebral cortex and subcortically in the limbic system.
limbic system (dopamine hypothesis)
has a variety of subcortical structures engaged in functions such as emotions, memory and arousal. nerves leave this areato other subcortical struvtures and the cerebral cortex.
mesolimbic pathway
signals are carried from the ventral tegmental area to the nucleus cumbers.
too much dopamine leads to overstimulation and positive symptoms.
antipsychotics reduce this dopaminergic transmission
mesocortical pathway
signals are carried from the ventral tegmental area to the frontal lobe.
this is vital in emotional responses, motivation and cognition
Davis et al (1991) found that too little dopamine is evident in the D1 receptors of the frontal lobe of many people with negative symptoms of schizophrenia
kety et al (1988) dopamine hypothesis
14% of the biological relative of adoptees w ith schizophrenia were classified as schizophrenic themselves, whereas only 2.7% of their adoptive relatives were found to be schizophrenic
shows sz has a genetic basis however its a denmark only study and the small sample reduces reliability
torrey 2002
the ventricles of a person with schizophrenia are about 15% bigger than normal
does not prove causation, other factors may contribute
strengths of dopamine hypothesis
gottesman (1991) found that the concordance rate between MZ twins was 48% but only 17% for dizygotic twins. as MZ and DZ twins both share the same environment, the higher concordance rate in the MZ twins may be due to their shared genes.
this shows that as genetic similarity increases so did the probability of both individuals having schizophrenia- demonstrates a strong relationship between genetics and schizophrenia
weaknesses of dopamine hypothesis (not a single gene)
the Schizophrenia working group of the psychiatric genomics consortium identified over a hundred genes associated with schizophrenia. as it appears there isnt one single gene associated with achizophrenia, perhaps there is not one disorder that may be called schizophrenia.
this shows that the relationship is a complex matter and more than just a few abnormal genes. reductionism
weakness of dopamine hypothesis (not the only neurotransmitter)
dopamine is not the only neurotransmitter implicated in schizophrenia, serotonin has also been found to influence the disorder. newer a-typical antipsychotics work on some serotonin receptors such as 5HT2A. this suggests that this is not the only explanation for schizophrenia, for example negative symptoms have an overlap with depression.
weakness of dopamine hypothesis (cause and effect)
coplov and cook (2000) found when using a PET scan they were not even able to detect differences in the dopamine activity of individuals with schizophrenia and those without. may be some time before we know for certain if dopamine imbalances cause schizophrenia or if schizophrenia causes dopamine imbalances.
this suggests that there could be other factors, just a relationship
four ventricles (structural abnormalities)
left and right lateral ventricles, third ventricle is sittuated behind the left and right thalamus, fourth ventricle lies between the pons and the medulla
weinberger et al (1979)
used CAT scans and found the size of the ventricles was larger in 58 individuals with chronic schizophrenia then 56 in the control group who didnt have schizophrenia
andreasen (1988)
studied MRI scans of individuals with and without schizophrenia and found that those with schizophrenia tended to have 20-50% larger ventricles than those without the illness
cortical atrophy
this is the loss of neurons in the cerebral cortex. it can occur all over the brain making it look as though it had shrunk, or the atrophy can occur in a limited area. this damage seems to characterise the brains of 20-30% of people with chronic schizophrenia
vita et al (1988) (cortical atrophy)
used CAT scans to assess 124 individuals with schizophrenia and 45 control participants. 33% with schizophrenia showed moderate to severe atrophy.
reversed cerebral asymmetry
in most individuals without schizophrenia the left hemisphere is slightly larger than the right hemisphere. however, in some with schizophrenia the right is larger than the left. if you consider that the language function is usually in the left hemisphere, this could explain alogia which is associated with schizophrenia
strength of structural abnormalities
the findings are highly reliable, the same structural abnormalities are found time after time when studies are replicated. McCarley (1999) found that enlarged brain ventricles were the most reliable finding in research that uses brain scans
weakness of structural abnormalities (struc differences are the cause)
if the brains of schizophrenics differ to that of contriols, it may be that structural differences are the cause of the illness. however, it may be that the illness causes structural abnormalities or a combination of the two. Lyon (1981) found that as levels of antipsychotics in patients increased, the density of brain tissue decreased.
this shows that once schizophrenia has been treated it could actually be the medication that causes the abnormality.
weakness of structural abnormalities (not only linked to schizophrenia)
structural abnormalities are not only linked to schizophrenia. Roy et al (1998) found that people who were diagnosed with bipolar disorder and schizoaffective disorder have also been found to have enlarged ventricles. this shows that there are overlapping symptoms, suggesting that they either have a similar cause or the classification needs to be reviewed.
