#bloa study

[ib-psych0logy]

Wong et al. (1986)

Who?

Wong et al.

When?

1986

Information found in:

Daisy’s Schizophrenia leaflet

Aim:

To research how dopamine could be a cause of schizophrenia

Research Method:

Quasi/Natural Experiment

Design:

Independent Measures

Participants:

Participants with schizophrenia and a control group without schizophrenia.

Procedure:

Conducted PET scans to see activity in the brain and dopamine receptor density.

Findings:

People with schizophrenia had a higher density of dopamine receptors in the caudate nuclei (in the cerebrum of the brain) than those without schizophrenia.

Conclusion:

Supports dopamine theory of schizophrenia.

Evaluation:

JDopamine and receptors are involved in schizophrenia but we don’t yet know exactly how.

JMore recent brain scanning techniques have shown that structural abnormalities are common in schizophrenic patients – further supporting the theory.

:) Uses scientific measures and equipment.

:( Subsequent studies have not supported these findings.

:( Lots of arguments over environment vs genes.

Learning Objectives:

Discuss the use of brain imaging technologies in investigating the relationships between biological factors and behaviour.

[ib-psych0logy]

Srivastava & Sharma (1998)

Who?

Srivastava & Sharma

When?

1998

Information found in:

Class Notes

Aim:

To examine the prevalence and effects of SAD in a sample of people living in India

Research Method:

  Design:

  Participants:

93 SAD patients, all diagnosed with a recurrent mood disorder measured by two diagnosed episodes of depression in the past (mostly male).

Procedure:

The sample was split into two groups: those with seasonal pattern of recurrent mood disorder and those without a pattern.

Findings:

18 out of 93 participants (19.4%) had a seasonal disorder.

Ppts with s seasonal disorder also had reduced libido

SAD seemed to afflict people who live at lower altitudes where there is less fluctuation in the amount of daylight experienced

Conclusion:

  Evaluation:

  :( Some ppts experienced summer depression – doesn’t have many explanations. Could be evidence for social aspects causing SAD.

:( Ppts already had mental health problem. SAD would be co-morbid. We don’t know the causes or effects of the other illness.

Learning Objectives:

Discuss two effects of the environment on physiological processes

[ib-psych0logy]

Maguire (2000)

Who?

Maguire

When?

2000

Information found in:

Class notes

Aim:

To investigate the role of the hippocampus in navigational and spatial skills, and the extent to which the brain shows changes (plasticity) to these areas.

Research Method:

Quasi experiment

IV=taxi driver or not

DV=density of hippocampus

Design:

Independent measures

Participants:

16 male, right-handed taxi drivers

Control group of 50 – Maguire used old MRI scans

Procedure:

MRI scans analysed through:

VBM (voxel based morphometry)

Pixel counting

Findings:

Taxi drivers had greater grey matter volume in right posterior hippocampus

Significant positive correlation between length of time as a taxi driver and the density of grey matter in the right posterior hippocampus

Conclusion:

The brain has neuroplasticity

Evaluation:

:) Objective measures were used. E.g. the number of pixels were actually counted and MRI scans are scientific. It was qualitative data.

:) Results have important implications. E.g. gives evidence towards which can help people who have suffered disease or accident that effects the brain (e.g. stroke). Can be used for rehabilitation.

:( Quasi experiment so IV wasn’t manipulated by researchers. Therefore not all EVs were controlled. May have been individual differences between the groups e.g. the taxi drivers having naturally greater density not because they were taxi drivers.

:( Only male ppts. Lacks population validity and cannot generalise to females. However, most taxi drivers are male so can generalise to taxi driver population.

Learning Objectives:

Explain one study related to localisation of function in the brain.

Discuss two effects of the environment on physiological processes.

Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behaviour.

[ib-psych0logy]

Jagust et al. (2011)

Who?

Jagust et al.

When?

2011

Information found in:

Class notes

Aim:

To investigate how brain stimulating activities in early life can reduce the risk of Alzheimer’s disease (AD)

Research Method:

  Design:

  Participants:

65 healthy, cognitively normal people aged 60 and over

10 AD patients

11 healthy people in their 20s

Procedure:

They were asked questions about how mentally active had been during different periods in their lives starting age 6. Questions included whether they had read newspapers, went to the library, wrote letter or e-mails, and played games.

The ppts underwent extensive testing to assess their memory and thinking skills

Their brains were scanned using PET scanners to look for deposits of beta amyloid which could lead to AD.

Findings:

Those who had been the most mentally active had lower levels beta amyloid than those who had been less mentally active.

People who had only recently taken up crosswords and other mental exercises did not see much benefit.

Conclusion:

Engaging in mentally challenging activities earlier in life can help prevent/delay the effects of AD

Evaluation:

:) Measuring beta amyloid using PiB and PET scans is an objective and scientific measure

:) This study is useful for treatment/prevention of AD

:( The ppts were asked to recall memories from a long time ago and they may not be accurate

Learning Objectives:

Examine one interaction between cognition and physiology in terms of behaviour

[ib-psych0logy]

Huntley et al. (2011)

Who?

Huntley et al.

When?

2011

Information found in:

Class notes

Aim:

To investigate how ‘chunking’ affects memory in patients with mild Alzheimer’s disease (AD) and in a control group of elderly people without cognitive impairment

Research Method:

Quasi Experiment

Design:

Independent Measures

Participants:

28 mild and very mild Alzheimer’s patients

Control group of 15 elderly people (matched on age, gender and level of education but not IQ)

Procedure:

All the participants performed digit and spatial working memory tasks requiring either unstructured sequences or structured sequences (which encourages chunking of information) to be recalled.

Findings:

All groups performed significantly better on structured trials of the digit working memory tasks than unstructured.

The control and very mild disease groups also performed significantly better on structured trials of the spatial task.

The mild disease group had no significant difference between the structured and unstructured spatial conditions.

Conclusion:

The ability to use chunking as an encoding strategy to improve verbal working memory performance is preserved at the mild stage of AD but chunking for spatial working memory is impaired by this stage. Simple training in the use of chunking might be a beneficial therapeutic strategy to prolong working memory for early AD patients.

Evaluation:

:) Use of matched control group so results can be directly compared

:) Useful because training in chunking could help to prolong the functionality of working memory

:( The control wasn’t matched on IQ level

:( Doesn’t explicitly show that chunking was actually used to remember the digits.

Learning Objectives:

Examine one interaction between cognition and physiology in terms of behaviour

[ib-psych0logy]

Gottesman & Shields (1976)

Who?

Gottesman & Shields

When?

1976

Information found in:

A2 OCR Psychology Textbook

978-0-435806-95-4

Aim:

To review research on genetic transmission of schizophrenia.

Research Method:

Review of adoption and twin studies into schizophrenia.

Design:

Correlational?

Participants:

Three adoption studies: 711 participants

Five twin studies: 210 monozygotic twins; 319 dizygotic twins;

Procedure:

They reviewed whether schizophrenia was present in biological families and adopted families

The concordance rates for twins were compared.

Findings:

All three adoption studies found increased incidence of schizophrenia in adopted children when their biological parents had schizophrenia.

Kety (1975) found that biological siblings had a higher percentage of schizophrenia (19.2%) than adoptive siblings (6.3%).

All five twin studies found a higher concordance rate of schizophrenia between monozygotic twins than dizygotic twins.

Gottesman and Shields own twin study found a 58% concordance rate in monozygotic twins but only a 12% concordance rate in dizygotic twins.

Conclusion:

The research reviewed shows that a key factor in schizophrenia is genetics and nature. It may be that dopamine is more present in some families than others. However, even when there wasn’t a biological family member with schizophrenia, it was still present so it shows an element of nature and environment in the development of schizophrenia.

  Evaluation:

:) The adoption studies were high in internal validity because the participants with schizophrenia grew up in an environment without schizophrenia as their adoptive parents didn’t suffer from it.

:) There could be no possible effect of demand characteristics or investigator effects because they used concordance rates as opposed to looking at behaviour.

:( In the twin studies they may have been genetically predisposed to schizophrenia but having a twin with schizophrenia meant the environment could have an effect so lack internal validity.

Learning Objectives:

Outline principles that define the biological level of analysis

Explain how principles that define the biological level of analysis may be demonstrated in research

With reference to relevant studies, to what extent does genetic inheritance influence behaviour?

[ib-psych0logy]

Fisher (2005)

Who?

Fisher

When?

2005

Information found in:

Class notes

Aim:

  Research Method:

Lab Experiment

IV=picture of ‘lover’ or neutral stimulus

DV=dopamine activity in the brain

Design:

Repeated Measures

Participants:

17

Procedure:

Used fMRI scans and should the ppts pictures of their ‘lovers’ or neutral stimuli.

Findings:

The dopamine pathways/region were activated when they were shown pictures of loved ones.

Conclusion:

  Evaluation:

    Learning Objectives:

Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behaviour